/shared/codes.php

<?php
/**
 * Transform some text containing UBB-like code sequences.
 *
 * @todo CDATA for proxy http://javascript.about.com/library/blxhtml.htm
 * @todo &#91;files] - most recent files, in a compact list
 * @todo &#91;files=section:&lt;id>] - files attached in the given section
 * @todo &#91;links] - most recent links, in a compact list
 * @todo &#91;links=section:&lt;id>] - links attached in the given section
 * @todo for [read, add hits aside
 * @todo add a code to link images with clickable maps
 * @todo replace marquee with our own customizable scroller
 * @todo WiKi rendering for lists
 *
 * This module uses the Skin class for the actual rendering.
 *
 * Basic codes, demonstrated into [link]codes/basic.php[/link]:
 * - **...** - wiki bold text
 * - &#91;b]...[/b] - bold text
 * - //...// - italics
 * - &#91;i]...[/i] - italics
 * - __...__ - underlined
 * - &#91;u]...[/u] - underlined
 * - ##...## - monospace
 * - &#91;code]...[/code] - a short sample of fixed-size text (e.g. a file name)
 * - &#91;color]...[/color] - change font color
 * - &#91;tiny]...[/tiny] - tiny size
 * - &#91;small]...[/small] - small size
 * - &#91;big]...[/big] - big size
 * - &#91;huge]...[/huge] - huge size
 * - &#91;subscript]...[/subscript] - subscript
 * - &#91;superscript]...[/superscript] - superscript
 * - ++...++ - inserted
 * - &#91;inserted]...[/inserted] - inserted
 * - --...-- - deleted
 * - &#91;deleted]...[/deleted] - deleted
 * - &#91;flag]...[/flag] - draw attention
 * - &#91;lang=xy]...[/lang] - show some text only on matching language
 * - &#91;style=sans-serif]...[/style] - use a sans-serif font
 * - &#91;style=serif]...[/style] - use a serif font
 * - &#91;style=cursive]...[/style] - mimic hand writing
 * - &#91;style=comic]...[/style] - make it funny
 * - &#91;style=fantasy]...[/style] - guess what will appear
 * - &#91;style=my_style]...[/style] - translated to &lt;span class="my_style"&gt;...&lt;/span&gt;
 *
 * @see codes/basic.php
 *
 * Block codes, demonstrated in [link]codes/blocks.php[/link]:
 * - &#91;indent]...[/indent] - shift text to the right
 * - &#91;center]...[/center] - some centered text
 * - &#91;right]...[/right] - some right-aligned text
 * - &#91;decorated]...[/decorated] - some pretty paragraphs
 * - &#91;caution]...[/caution] - a warning paragraph
 * - &#91;note]...[/note] - a noticeable paragraph
 * - &#91;php]...[/php] - a snippet of php
 * - &#91;snippet]...[/snippet] - a snippet of fixed font data
 * - &#91;quote]...[/quote] - a block of quoted text
 * - &#91;folded]...[/folded] - click to view its content, or to fold it away
 * - &#91;folded=foo bar]...[/folded] - with title 'foo bar'
 * - &#91;unfolded]...[/unfolded] - click to fold
 * - &#91;unfolded=foo bar]...[/unfolded] - with title 'foo bar'
 * - &#91;sidebar]...[/sidebar] - a nice box aside
 * - &#91;sidebar=foo bar]...[/sidebar] - with title 'foo bar'
 * - &#91;scroller]...[/scroller] - some scrolling text
 *
 * @see codes/blocks.php
 *
 * List codes, demonstrated in [link]codes/lists.php[/link]:
 * - &#91;*] - for simple lists
 * - &#91;list]...[/list] - bulleted list
 * - &#91;list=1]...[/list] - numbered list, use numbers
 * - &#91;list=a]...[/list] - numbered list, use letters
 * - &#91;list=A]...[/list] - numbered list, use capital letters
 * - &#91;list=i]...[/list] - numbered list, use roman numbers
 * - &#91;list=I]...[/list] - numbered list, use upper case roman numbers
 *
 * @see codes/lists.php
 *
 * Codes for links, demonstrated in [link]codes/links.php[/link]:
 * - &lt;url&gt; - &lt;a href="url">url&lt;/a> or &lt;a href="url" class="external">url&lt;/a>
 * - &#91;link]&lt;url&gt;[/link] - &lt;a href="url">url&lt;/a> or &lt;a href="url" class="external">url&lt;/a>
 * - &#91;&lt;label&gt;|&lt;url&gt;] - &lt;a href="url">label&lt;/a> or &lt;a href="url" class="external">label&lt;/a>
 * - &#91;link=&lt;label&gt;]&lt;url&gt;[/link] - &lt;a href="url">label&lt;/a> or &lt;a href="url" class="external">label&lt;/a>
 * - &#91;url]&lt;url&gt;[/url] - deprecated by &#91;link]
 * - &#91;url=&lt;url&gt;]&lt;label&gt;[/url] - deprecated by &#91;link]
 * - &#91;button=&lt;label&gt;|&lt;url&gt;] - build simple buttons with css
 * - &#91;click=&lt;label&gt;|&lt;url&gt;] - a button that counts clicks
 * - &#91;clicks=&lt;url&gt;] - lists people who have clicked
 * - &lt;address&gt; - &lt;a href="mailto:address" class="email">address&lt;/a>
 * - &#91;email]&lt;address&gt;[/email] - &lt;a href="mailto:address" class="email">address&lt;/a>
 * - &#91;email=&lt;name&gt;]&lt;address&gt;[/email] - &lt;a href="mailto:address" class="email">name&lt;/a>
 * - &#91;go=&lt;name&gt;, &lt;label&gt;] - trigger the selector on 'name'
 * - &#91;&#91;&lt;name&gt;, &lt;label&gt;]] - Wiki selector
 * - &#91;article=&lt;id>] - use article title as link label
 * - &#91;article=&lt;id>, foo bar] - with label 'foo bar'
 * - &#91;article.description=&lt;id>] - insert article description
 * - &#91;form=&lt;id>] - use form title as link label
 * - &#91;form=&lt;id>, foo bar] - with label 'foo bar'
 * - &#91;next=&lt;id>] - shortcut to next article
 * - &#91;next=&lt;id>, foo bar] - with label 'foo bar'
 * - &#91;previous=&lt;id>] - shortcut to previous article
 * - &#91;previous=&lt;id>, foo bar] - with label 'foo bar'
 * - &#91;random] - pick up one page randomly
 * - &#91;random=&lt;section:id>] - one page in this section
 * - &#91;section=&lt;id>] - use section title as link label
 * - &#91;section=&lt;id>, foo bar] - with label 'foo bar'
 * - &#91;category=&lt;id>] - use category title as link label
 * - &#91;category=&lt;id>, foo bar] - with label 'foo bar'
 * - &#91;category.description=&lt;id>] - insert category description
 * - &#91;decision=&lt;id>] - use decision id in link label
 * - &#91;decision=&lt;id>, foo bar] - with label 'foo bar'
 * - &#91;user=&lt;id>] - use nick name as link label
 * - &#91;user=&lt;id>, foo bar] - with label 'foo bar'
 * - &#91;server=&lt;id>] - use server title as link label
 * - &#91;server=&lt;id>, foo bar] - with label 'foo bar'
 * - &#91;file=&lt;id>] - use file title as link label
 * - &#91;file=&lt;id>, foo bar] - with label 'foo bar'
 * - &#91;download=&lt;id>] - a link to download a file
 * - &#91;download=&lt;id>, foo bar] - with label 'foo bar'
 * - &#91;comment=&lt;id>] - use comment id in link label
 * - &#91;comment=&lt;id>, foo bar] - with label 'foo bar'
 * - &#91;script]&lt;path/script.php&gt;[/script] - to the phpDoc page for script 'path/script.php'
 * - &#91;search] - a search form
 * - &#91;search=&lt;word&gt;] - hit Enter to search for 'word'
 * - &#91;action=&lt;id>] - use action title as link label
 * - &#91;action=&lt;id>, foo bar] - with label 'foo bar'
 * - &#91;wikipedia=&lt;keyword] - search Wikipedia
 * - &#91;wikipedia=&lt;keyword, foo bar] - search Wikipedia, with label 'foo bar'
 *
 * @see codes/links.php
 *
 * Titles and questions, demonstrated in [link]codes/titles.php[/link]:
 * - &#91;toc] - table of contents
 * - ==...== - a level 1 headline
 * - &#91;title]...[/title] - a level 1 headline, put in the table of contents
 * - ===...=== - a level 2 headline
 * - &#91;subtitle]...[/subtitle] - a level 2 headline
 * - &#91;header1]...[/header1] - a level 1 headline
 * - &#91;header2]...[/header2] - a level 2 headline
 * - &#91;header3]...[/header3] - a level 3 headline
 * - &#91;header4]...[/header4] - a level 4 headline
 * - &#91;header5]...[/header5] - a level 5 headline
 * - &#91;toq] - the table of questions for this page
 * - &#91;question]...[/question] - a question-title
 * - &#91;question] - a simple question
 * - &#91;answer] - some answer in a FAQ
 *
 * @see codes/titles.php
 *
 * Tables, demonstrated in [link]codes/tables.php[/link]:
 * - &#91;table]...[/table] - one simple table
 * - &#91;table=grid]...[/table] - add a grid
 * - &#91;table].[body].[/table] - a table with headers
 * - &#91;csv]...[/csv] - import some data from Excel
 * - &#91;csv=;]...[/csv] - import some data from Excel
 * - &#91;table.json] - format a table as json
 *
 * @see codes/tables.php
 *
 * Live codes, demonstrated in [link]codes/live.php[/link]:
 * - &#91;sections] - site map
 * - &#91;sections=section:&lt;id>] - sub-sections
 * - &#91;sections=self] - sections assigned to current surfer
 * - &#91;sections=user:&lt;id>] - sections assigned to given user
 * - &#91;categories] - category tree
 * - &#91;categories=category:&lt;id>] - sub-categories
 * - &#91;categories=self] - categories assigned to current surfer
 * - &#91;categories=user:&lt;id>] - categories assigned to given user
 * - &#91;published] - most recent published pages, in a compact list
 * - &#91;published=section:&lt;id>] - articles published most recently in the given section
 * - &#91;published=category:&lt;id>] - articles published most recently in the given category
 * - &#91;published=user:&lt;id>] - articles published most recently created by given user
 * - &#91;published.decorated=self, 20] - 20 most recent pages from current surfer, as a decorated list
 * - &#91;updated] - most recent updated pages, in a compact list
 * - &#91;updated=section:&lt;id>] - articles updated most recently in the given section
 * - &#91;updated=category:&lt;id>] - articles updated most recently in the given category
 * - &#91;updated=user:&lt;id>] - articles updated most recently created by given user
 * - &#91;updated.simple=self, 12] - articles updated most recently created by current surfer, as a simple list
 * - &#91;read] - most read articles, in a compact list
 * - &#91;read=section:&lt;id>] - articles of fame in the given section
 * - &#91;read=self] - personal hits
 * - &#91;read=user:&lt;id>] - personal hits
 * - &#91;voted] - most voted articles, in a compact list
 * - &#91;voted=section:&lt;id>] - articles of fame in the given section
 * - &#91;voted=self] - personal hits
 * - &#91;voted=user:&lt;id>] - personal hits
 * - &#91;collections] - list available collections
 * - &#91;users=present] - list of users present on site
 *
 * @see codes/live.php
 *
 * Widgets, demonstrated in [link]codes/widgets.php[/link]:
 * - &#91;newsfeed=url] - integrate a newsfeed dynamically
 * - &#91;newsfeed.embed=url] - integrate a newsfeed dynamically
 * - &#91;twitter=id] - twitter updates of one person
 * - &#91;tsearch=token] - twitter search on a given topic
 * - &#91;iframe=&lt;width&gt;, &lt;height&gt;]&lt;url&gt;[/iframe] - include some external page
 * - &#91;freemind] - a Freemind map of site content
 * - &#91;freemind=section:&lt;id>] - a Freemind map of a section and its content
 * - &#91;freemind=section:&lt;id>, width, height] - a Freemind map of a section and its content
 * - &#91;cloud] - the tags used at this site
 * - &#91;cloud=12] - maximum count of tags used at this site
 * - &#91;calendar] - events for this month
 * - &#91;calendar=section:&lt;id>] - dates in one section
 * - &#91;locations=all] - newest locations
 * - &#91;locations=users] - map user locations on Google maps
 * - &#91;location=latitude, longitude, label] - to build a dynamic map
 *
 * @see codes/widgets.php
 *
 * Miscellaneous codes, demonstrated in [link]codes/misc.php[/link]:
 * - &#91;chart]...[/chart] - draw a dynamic chart
 * - &#91;hint=&lt;help popup]...[/hint] - &lt;acronym tite="help popup">...&lt;/acronym>
 * - &#91;nl] - new line
 * - ----... - line break
 * - &#91;---] or &#91;___] - horizontal rule
 * - &#91;new] - something new
 * - &#91;popular] - people love it
 * - &#91;be] - country flag
 * - &#91;ca] - country flag
 * - &#91;ch] - country flag
 * - &#91;de] - country flag
 * - &#91;en] - country flag
 * - &#91;es] - country flag
 * - &#91;fr] - country flag
 * - &#91;gb] - country flag
 * - &#91;gr] - country flag
 * - &#91;it] - country flag
 * - &#91;pt] - country flag
 * - &#91;us] - country flag
 *
 * @see codes/misc.php
 *
 * In-line elements:
 * - &#91;embed=&lt;id>, &lt;width>, &lt;height>, &lt;flashparams>] - embed a multimedia file
 * - &#91;embed=&lt;id>, window] - render a multimedia file in a separate window
 * - &#91;freemind=&lt;id>] - a Freemind map out of given file
 * - &#91;sound=&lt;id>] - play a sound
 * - &#91;image=&lt;id>] - an inline image
 * - &#91;image=&lt;id>,left] - a left-aligned image
 * - &#91;image=&lt;id>,center] - a centered image
 * - &#91;image=&lt;id>,right] - a right-aligned image
 * - &#91;image]src[/image]
 * - &#91;image=&lt;alt>]src[/image]
 * - &#91;images=&lt;id1>, &lt;id2>, ...] - a stack of images
 * - &#91;img]src[/img] (deprecated)
 * - &#91;img=&lt;alt>]src[/img] (deprecated)
 * - &#91;table=&lt;id>] - an inline table
 * - &#91;location=&lt;id>] - embed a map
 * - &#91;location=&lt;id>, foo bar] - with label 'foo bar'
 * - &#91;clear] - to introduce breaks after floating elements
 *
 * @link http://www.estvideo.com/dew/index/2005/02/16/370-player-flash-mp3-leger-comme-une-plume the dewplayer page
 *
 * Other codes:
 * - &#91;menu=label]url[/menu] -> one of the main menu command
 * - &#91;submenu=label]url[/submenu]	-> one of the second-level menu commands
 * - &#91;escape]...[/escape]
 * - &#91;anonymous]...[/anonymous] 	-> for non-logged people only
 * - &#91;restricted]...[/restricted]		-> for logged members only
 * - &#91;hidden]...[/hidden]		-> for associates only
 * - &#91;parameter=name]	-> value of one attribute of the global context
 *
 *
 * This script attempts to fight bbCode code injections by filtering strings to be used
 * as [code]src[/code] or as [code]href[/code] attributes (Thank you Mordread).
 *
 * @author Bernard Paques
 * @author Mordread Wallas
 * @author GnapZ
 * @author Alain Lesage (Lasares)
 * @tester Viviane Zaniroli
 * @tester Agnes
 * @tester Pat
 * @tester Guillaume Perez
 * @tester Fw_crocodile
 * @tester Christian Piercot
 * @tester Christian Loubechine
 * @reference
 * @license http://www.gnu.org/copyleft/lesser.txt GNU Lesser General Public License
 */
Class Codes {

	/**
	 * beautify some text for final rendering
	 *
	 * This function is used to transform some text before sending it back to the browser.
	 * It actually performs following analysis:
	 * - implicit formatting
	 * - formatting codes
	 * - smileys
	 *
	 * If the keyword [escape][formatted][/escape] appears at the first line of text,
	 * or if options have the keyword ##formatted##, no implicit formatting is performed.
	 *
	 * If the keyword [escape][hardcoded][/escape] appears at the first line of text,
	 * or if options have the keyword ##hardcoded##, the only transformation is is new lines to breaks.
	 *
	 * If options feature the keyword ##compact##, then YACS codes that may
	 * generate big objects are removed, such as [escape][table]...[/table][/escape]
	 * and [escape][location][/escape].
	 *
	 * @param string the text to beautify
	 * @param string the set of options that apply to this text
	 * @return the beautified text
	 *
	 * @see articles/view.php
	 */
	function &beautify($text, $options='') {
		global $context;

		// save CPU cycles
		$text = trim($text);
		if(!$text)
			return $text;

		//
		// looking for compact content
		//
		if(preg_match('/\bcompact\b/i', $options))
			$text = preg_replace(array('/\[table.+?\/table\]/', '/\[location.+?\]/'), '', $text);

		//
		// implicit formatting
		//

		// new lines will have to be checked
		$new_lines = 'proceed';

		// text is already formatted
		if(!strncmp($text, '[formatted]', 11)) {
			$new_lines = 'none';
			$text = substr($text, 11);

		// text is already formatted (through options)
		} elseif(preg_match('/\bformatted\b/i', $options))
			$new_lines = 'none';

		// newlines are hard coded
		elseif(!strncmp($text, '[hardcoded]', 11)) {
			$new_lines = 'hardcoded';
			$text = substr($text, 11);

		// newlines are hard coded (through options)
		} elseif(preg_match('/\bhardcoded\b/i', $options))
			$new_lines = 'hardcoded';

		// implicit formatting
		else
			$text =& Codes::beautify_implied($text, 'text');

		//
		// translate codes
		//

		// render codes
		$text =& Codes::render($text);

		// render smileys after codes, else it will break escaped strings
		if(is_callable(array('Smileys', 'render_smileys')))
			$text =& Smileys::render_smileys($text);

		// relocate images
		$text = str_replace('"skins/', '"'.$context['path_to_root'].'skins/', $text);

		//
		// adjust end of lines
		//

		// newlines are hard coded
		if($new_lines == 'hardcoded')
			$text = nl2br($text);

		// implicit formatting
		elseif($new_lines == 'proceed')
			$text =& Codes::beautify_implied($text, 'newlines');

		return $text;
	}

	/**
	 * beautify some text in the extra panel
	 *
	 * @param string the text to beautify
	 * @return the beautified text
	 *
	 * @see articles/view.php
	 */
	function &beautify_extra($text) {
		global $context;

		$search = array();
		$replace = array();

		// [box.extra=title]...[/box]
		$search[] = '/\[box\.(extra)=([^\]]+?)\](.*?)\[\/box\]/ise';
		$replace[] = "Skin::build_box(stripslashes('$2'), stripslashes('$3'), '$1')";

		// [box.navigation=title]...[/box]
		$search[] = '/\[box\.(navigation)=([^\]]+?)\](.*?)\[\/box\]/ise';
		$replace[] = "Skin::build_box(stripslashes('$2'), stripslashes('$3'), '$1')";

		// process all codes
		$text = preg_replace($search, $replace, $text);

		// regular rendering
		$text =& Codes::beautify($text);

		return $text;

	}

	/**
	 * render some basic formatting
	 *
	 * - suppress multiple newlines
	 * - render empty lines
	 * - render simple bulleted lines
	 * - make URL clickable (http://..., www.foo.bar, foo.bar@foo.com)
	 *
	 * Now this function looks for the keyword &#91;escape] in order
	 * to avoid for formatting pre-formatted areas.
	 *
	 * For example, if you type:
	 * [snippet]
	 * hello
	 * world
	 *
	 * how are
	 * you doing?
	 *
	 * - my first item
	 * - my second item
	 *
	 * > quoted from
	 * > a previous message
	 * [/snippet]
	 *
	 * This will be rendered visually in the browser as:
	 * [snippet]
	 * hello world
	 *
	 * how are you doing?
	 *
	 * - my first item
	 * - my second item
	 *
	 * > quoted from
	 * > a previous message
	 * [/snippet]
	 *
	 * @param string the text to transform
	 * @param sring either 'text' or 'newlines'
	 * @return the modified string
	 */
	function &beautify_implied($text, $variant='text') {

		// streamline newlines, even if this has been done elsewhere
		$text = str_replace(array("\r\n", "\r"), "\n", $text);

		// only change end of lines
		if($variant == 'newlines') {

			// formatting patterns
			$search = array(
				"|<br\s*/>\n+|i",		/* don't insert additional \n after <br /> */
				"|\n\n+|i"				/* force an html space between paragraphs */
				);

			$replace = array(
				BR,
				BR.BR
				);

		// change everything, except new lines
		} else {

			// formatting patterns
			$search = array(
				"|</h1>\n+|i",			/* strip \n after title */
				"|</h2>\n+|i",
				"|</h3>\n+|i",
				"|</h4>\n+|i",
				'/http:\/\/www\.youtube\.com\/watch\?v=([a-zA-Z0-9]+)/i', // YouTube link
				"#^([a-z]+?)://([a-z0-9_\-\.\~\/@&;:=%$\?]+)#ie", /* make URL clickable */
				"#([\n\t ])([a-z]+?)://([a-z0-9_\-\.\~\/@&;:=%$\?]+)#ie", /* make URL clickable */
				"#([\n\t \(])www\.([a-z0-9\-]+)\.([a-z0-9_\-\.\~]+)((?:/[^,< \r\n\)]*)?)#ie",	/* web server */
				"/^\<p\>(-|\*)\s+(.+)\<\/p\>$/im", /* lists hard-coded with -, *, ¤, or • -- no space ahead */
				"/^(-|\*)\s+(.+)$/m", /* lists hard-coded with -, *, ¤, or • -- no space ahead */
				"/\n[ \t]*(From|To|cc|bcc|Subject|Date):(\s*)/i",	/* common message headers */
				"|\n[ \t]*>(\s*)|i",		/* quoted by > */
				"|\n[ \t]*\|(\s*)|i",		/* quoted by | */
				"#([\n\t ])(mailto:|)([a-z0-9_\-\.\~]+?)@([a-z0-9_\-\.\~]+\.[a-z0-9_\-\.\~]+)([\n\t ]*)#ie" /* mail address*/
				);

			$replace = array(
				"</h1>",
				"</h2>",
				"</h3>",
				"</h4>",
				'<iframe class="youtube-player" type="text/html" width="445" height="364" src="http://www.youtube.com/embed/$1" frameborder="0"></iframe>', // YouTube link
				"Skin::build_link('$1://$2', '$1://$2')",
				"'$1'.Skin::build_link('$2://$3', '$2://$3')",
				"'$1'.Skin::build_link('http://www.$2.$3$4', 'www.$2.$3$4')",
				"<ul><li>$2</li></ul>",
				"<ul><li>$2</li></ul>",
				BR."$1:$2",
				BR.">$1",
				BR."|$1",
				"'$1'.Skin::build_link('mailto:$3@$4', '$3@$4', 'email').'$5'"
				);
		}

		// preserve escaped areas
		$text = str_replace(array('[escape]', '[/escape]', '[list]', '[/list]', '[php]', '[/php]', '[snippet]', '[/snippet]'),
			array('<escape>', '</escape>', '<list>', '</list>', '<php>', '</php>', '<snippet>', '</snippet>'), $text);

		// locate pre-formatted areas
		$areas = preg_split('/<(code|escape|list|php|snippet|pre)>(.*?)<\/\1>/is', trim($text), -1, PREG_SPLIT_DELIM_CAPTURE);

		// format only adequate areas
		$index = 0;
		$formatted = '';
		$inside = FALSE;
		$target = '';
		foreach($areas as $area) {

			switch($index%3) {
			case 0: // area to be formatted

				// do not rewrite tags
				$items = preg_split('/<(.+?)>/is', $area, -1, PREG_SPLIT_DELIM_CAPTURE);
				$where = 0;
				foreach($items as $item) {

					switch($where%2) {

					case 0: // outside a tag
						if($inside)
							$target .= $item;
						else
							$formatted .= preg_replace($search, $replace, $item);
						break;

					case 1: // inside a tag

						// inside or outside a link
						if($inside && !strncmp($item, '/a', 2)) {
							$formatted .= preg_replace($search, $replace, $target).'<'.$item.'>';
							$target = '';
							$inside = FALSE;
						} elseif($inside)
							$target .= '<'.$item.'>';
						elseif(!strncmp($item, 'a ', 2)) {
							$formatted .= '<'.$item.'>';
							$inside = TRUE;
						} else
							$formatted .= '<'.$item.'>';
						break;

					}
					$where++;
				}
				break;

			case 1: // area boundary
				$tag = $area;
				break;

			case 2: // pre-formatted area - left unmodified

				// inside a link, or regular text
				if($inside)
					$target .= '<'.$tag.'>'.$area.'</'.$tag.'>';
				else
					$formatted .= '<'.$tag.'>'.$area.'</'.$tag.'>';
				break;

			}
			$index++;
		}

		// post-optimization
		if($variant == 'text')
			$formatted = preg_replace('#</ul>\n{0,1}<ul>#', '', $formatted);
		$formatted = preg_replace('#\n\n+<ul#', "\n<ul", $formatted);

		// restore escaped areas
		$formatted = str_replace(array('<escape>', '</escape>', '<list>', '</list>', '<php>', '</php>', '<snippet>', '</snippet>'),
			array('[escape]', '[/escape]', '[list]', '[/list]', '[php]', '[/php]', '[snippet]', '[/snippet]'), $formatted);

		return $formatted;
	}

	/**
	 * format an introduction
	 *
	 * @param string raw introduction
	 * @return string finalized title
	 */
	function &beautify_introduction($text) {

		// render codes
		$output =& Codes::render($text);

		// render smileys after codes, else it will break escaped strings
		if(is_callable(array('Smileys', 'render_smileys')))
			$output =& Smileys::render_smileys($output);

		// return by reference
		return $output;
	}

	/**
	 * format a title
	 *
	 * New lines and images are the only things accepted in titles.
	 * The goal is to provide a faster service than beautify()
	 *
	 * @param string raw title
	 * @return string finalized title
	 */
	function &beautify_title($text) {

		// suppress pairing codes
		$output =& Codes::strip($text);

		// the only code transformed in titles
		$output = str_replace(array('[nl]', '[NL]'), '<br />', $output);

		// remove everything, except links, breaks and images, and selected tags
		$output = strip_tags($output, '<a><abbr><acronym><b><big><br><code><del><div><dfn><em><i><img><ins><p><q><small><span><strong><sub><sup><tt><u>');

		// return by reference
		return $output;
	}

	/**
	 * determine if a code is already in some text
	 *
	 * @param string the text to check
	 * @param string code to check (e.g., 'embed')
	 * @param int the id of the object
	 * @return boolean TRUE if the code is present, false otherwise
	 */
	function check_embedded($text, $code, $id) {

		// we check the string of digits
		$id = strval($id);

		// parse the full string
		$count = strlen($text);
		$position = 0;

		// look for '[embed' or similar
		while(($position = strpos($text, '['.$code, $position)) !== FALSE) {
			$position += 1+strlen($code);

			// parse remaining chars
			while($position < $count) {

				// digits just follow the '=' sign
				if($text[$position] == '=') {
					$position++;

					// exact match
					if(($position + 2 + strlen($id) < $count) && !strcmp(substr($text, $position, strlen($id)), $id))
						return TRUE;

					// not in this code, look at next one
					break;

				// malformed code
				} elseif($text[$position] == ']') {
					$position++;
					break;
				}

				// next char
				$position++;
			}
		}

		// not found
		return FALSE;
	}

	/**
	 * delete a code if it is present in some text
	 *
	 * @param string the text to check
	 * @param string code to check (e.g., 'embed')
	 * @param int the id of the object
	 * @return string the resulting string
	 */
	function delete_embedded($text, $code, $id) {

		// we check the string of digits
		$id = strval($id);

		// parse the full string
		$count = strlen($text);
		$position = 0;

		// look for '[embed' or similar
		while(($position = strpos($text, '['.$code, $position)) !== FALSE) {

			// we have to take everything before that point
			$prefix = $position;

			// next char
			$position += 1+strlen($code);

			// parse remaining chars
			while($position < $count) {

				// digits just follow the '=' sign
				if($text[$position] == '=') {
					$position++;

					// exact match
					if(($position + strlen($id) <= $count) && !strcmp(substr($text, $position, strlen($id)), $id)) {
						$position += strlen($id);

						// look for ']'
						while($position < $count) {
							if($text[$position] == ']') {
								$position++;
								break;
							}
							$position++;
						}

						// do the deletion
						$modified = '';
						if($prefix > 0)
							$modified .= substr($text, 0, $prefix);
						if($position < $count)
							$modified .= substr($text, $position, $count-$position);
						return $modified;
					}

					// not in this code, look at next one
					break;

				// malformed code
				} elseif($text[$position] == ']') {
					$position++;
					break;
				}

				// next char
				$position++;
			}
		}

		// not found
		return $text;
	}

	/**
	 * fix line breaks introduced by FCKEditor
	 *
	 * This function moves unclosed tags to the beginning of content.
	 *
	 * @param string input
	 * @return string original or modified content
	 */
	function &fix_tags($text) {

		// look for opening tag at content end
		$last_open = strrpos($text, '<p>');
		$last_close = strrpos($text, '</p');
		if($last_open && (($last_close === FALSE) || ($last_open > $last_close))) {

			// trail
			$trail = '';
			if(strlen($text) > $last_open + 3)
				$trail = substr($text, $last_open + 3);

			// move it to content start to restore pairing tags
			$text = '<p>'.substr($text, 0, $last_open).$trail;

		}

		// also fix broken img tags, if any
		$text = preg_replace('/\<(img[^\<\/]+)\>/i', '<\\1 />', $text);

		// remove slashes added by preg_replace -- only for double quotes
		$text = str_replace('\"', '"', $text);

		// done
		return $text;
	}

	/**
	 * get the value of one global parameter
	 *
	 * @param string name of the parameter
	 * @param mixed default value, if any
	 * @return the actual value of this parameter, else the default value, else ''
	 */
	function &get_parameter($name, $default='') {
		global $context;

		if(isset($context[$name])) {
			$output =& $context[$name];
			return $output;
		}

		$output = $default;
		return $output;
	}

	/**
	 * reset global variables used for rendering
	 *
	 * This function should be called between the processing of different articles in a loop
	 *
	 * @param string the target URL for this rendering (e.g., 'articles/view.php/123')
	 */
	function initialize($main_target=NULL) {
		global $context;

		if($main_target)
			$context['self_url'] = $context['url_to_root'].$main_target;

	}

	/**
	 * list all ids matching some code
	 *
	 * @param string the text to check
	 * @param string code to check (e.g., 'embed')
	 * @return array the list of matching ids
	 */
	function list_embedded($text, $code='embed') {

		// all ids we have found
		$ids = array();

		// parse the full string
		$count = strlen($text);
		$position = 0;

		// look for '[embed' or similar
		while(($position = strpos($text, '['.$code, $position)) !== FALSE) {
			$position += 1+strlen($code);

			// parse remaining chars
			while($position < $count) {

				// digits just follow the '=' sign
				if($text[$position] == '=') {
					$position++;

					// capture all digits
					$id = '';
					while($position < $count) {
						if(($text[$position] >= '0') && ($text[$position] <= '9')) {
							$id .= $text[$position];
							$position++;
						} else
							break;
					}

					// save this id
					if(strlen($id))
						$ids[] = $id;

					// look at next code
					break;

				// malformed code
				} elseif($text[$position] == ']') {
					$position++;
					break;
				}

				// next char
				$position++;
			}
		}

		// job done
		return $ids;
	}

	/**
	 * transform codes to html
	 *
	 * [php]
	 * // build the page
	 * $context['text'] .= ...
	 *
	 * // transform codes
	 * $context['text'] = Codes::render($context['text']);
	 *
	 * // final rendering
	 * render_skin();
	 * [/php]
	 *
	 * @param string the input string
	 * @return string the transformed string
	 */
	function &render($text) {
		global $context;

		// streamline newlines, even if this has been done elsewhere
		$text = str_replace(array("\r\n", "\r"), "\n", $text);

		// prevent wysiwyg editors to bracket our own tags
		$text = preg_replace('/^<p>(\[.+\])<\/p>$/m', '\\1', $text);

 		// initialize only once
		static $pattern;
		if(!isset($pattern)) {

//			$pattern[] = ;
//			$replace[] = ;
//
//			$pattern[] = ;
//			$replace[] = ;
//
//			$pattern[] = ;
//			$replace[] = ;
//
//			$pattern[] = ;
//			$replace[] = ;
//
//			$pattern[] = ;
//			$replace[] = ;

			$pattern = array(
				"|<!-- .* -->|i",								// remove HTML comments
				'/\[escape\](.*?)\[\/escape\]/ise', 	// [escape]...[/escape] (before everything)
				'/\[php\](.*?)\[\/php\]/ise',			// [php]...[/php]
				'/\[snippet\](.*?)\[\/snippet\]/ise',	// [snippet]...[/snippet]
				'/(\[page\].*)$/is',					// [page] (provide only the first one)
				'/\[hidden\](.*?)\[\/hidden\]/ise', 	// [hidden]...[/hidden] (save some cycles if at the beginning)
				'/\[restricted\](.*?)\[\/restricted\]/ise', // [restricted]...[/restricted] (save some cycles if at the beginning)
				'/\[anonymous\](.*?)\[\/anonymous\]/ise', // [anonymous]...[/anonymous] (save some cycles if at the beginning)
				'/\[parameter=([^\]]+?)\]/ise', 		// [parameter=<name>]
				'/\[lang=([^\]]+?)\](.*?)\[\/lang\]/ise',		// [lang=xy]...[/lang]
				'/\[csv=(.)\](.*?)\[\/csv\]/ise',		// [csv=;]...[/csv] (before [table])
				'/\[csv\](.*?)\[\/csv\]/ise',			// [csv]...[/csv] (before [table])
				'/\[table=([^\]]+?)\](.*?)\[\/table\]/ise', // [table=variant]...[/table]
				'/\[table\](.*?)\[\/table\]/ise',		// [table]...[/table]
				'/\[images=([^\]]+?)\]/ie', 				// [images=<ids>] (before other links)
				'/\[image\](.*?)\[\/image\]/ise',		// [image]src[/image]
				'/\[image=([^\]]+?)\](.*?)\[\/image\]/ise', // [image=alt]src[/image]
				'/\[img\](.*?)\[\/img\]/ise',			// [img]src[/img]
				'/\[img=([^\]]+?)\](.*?)\[\/img\]/ise', 	// [img=alt]src[/img]
				'/\[image=([^\]]+?)\]/ie',					// [image=<id>]
				'/##(\S.*?\S)##/is',					// ##...##
				'/\[code\](.*?)\[\/code\]/is',			// [code]...[/code]
				'/\[indent\](.*?)\[\/indent\]/ise', 	// [indent]...[/indent]
				'/\[quote\](.*?)\[\/quote\]/ise',		// [quote]...[/quote]
				'/\[folded=([^\]]+?)\](.*?)\[\/folded\]\s*/ise',	// [folded=...]...[/folded]
				'/\[folded\](.*?)\[\/folded\]\s*/ise',	// [folded]...[/folded]
				'/\[folder=([^\]]+?)\](.*?)\[\/folder\]\s*/ise',	// [folder=...]...[/folder]
				'/\[folder\](.*?)\[\/folder\]\s*/ise',	// [folder]...[/folder]
				'/\[unfolded=([^\]]+?)\](.*?)\[\/unfolded\]\s*/ise',	// [unfolded=...]...[/unfolded]
				'/\[unfolded\](.*?)\[\/unfolded\]\s*/ise',	// [unfolded]...[/unfolded]
				'/\[sidebar=([^\]]+?)\](.*?)\[\/sidebar\]\s*/ise',	// [sidebar=...]...[/sidebar]
				'/\[sidebar\](.*?)\[\/sidebar\]\s*/ise',	// [sidebar]...[/sidebar]
				'/\[note\](.*?)\[\/note\]\s*/ise',		// [note]...[/note]
				'/\[caution\](.*?)\[\/caution\]\s*/ise', // [caution]...[/caution]
				'/\[search=([^\]]+?)\]/ise',				// [search=words]
				'/\[search\]/ise',						// [search]
				'/\[cloud=(\d+?)\]/ise',				// [cloud=12]
				'/\[cloud\]/ise',						// [cloud]
				'/\[collections\]/ise', 				// [collections]
				'/\[login=([^\]]+?)\]/is',				// [login=words] --obsoleted
				'/\[login\]/is',						// [login] --obsoleted
				'/\[center\](.*?)\[\/center\]/ise', 	// [center]...[/center]
				'/\[right\](.*?)\[\/right\]/ise',		// [right]...[/right]
				'/\[decorated\](.*?)\[\/decorated\]/ise',// [decorated]...[/decorated]
				'/\[style=([^\]]+?)\](.*?)\[\/style\]/ise', // [style=variant]...[/style]
				'/\[hint=([^\]]+?)\](.*?)\[\/hint\]/is',	// [hint=help]...[/hint]
				'/\[tiny\](.*?)\[\/tiny\]/ise', 		// [tiny]...[/tiny]
				'/\[small\](.*?)\[\/small\]/ise',		// [small]...[/small]
				'/\[big\](.*?)\[\/big\]/ise',			// [big]...[/big]
				'/\[huge\](.*?)\[\/huge\]/ise', 		// [huge]...[/huge]
				'/\[subscript\](.*?)\[\/subscript\]/is',// [subscript]...[/subscript]
				'/\[superscript\](.*?)\[\/superscript\]/is',// [superscript]...[/superscript]
				'/\+\+(\S.*?\S)\+\+/is',				// ++...++
				'/\[(---+|___+)\]\s*/ise',				// [---], [___] --- before inserted
				'/^-----*/me',							// ----
				'/\[inserted\](.*?)\[\/inserted\]/is',	// [inserted]...[/inserted]
				'/ --(\S.*?\S)--/is',					// --...--
				'/\[deleted\](.*?)\[\/deleted\]/is',	// [deleted]...[/deleted]
				'/\*\*(\S.*?\S)\*\*/is',				// **...**
				'/\[b\](.*?)\[\/b\]/is',				// [b]...[/b]
				'/ \/\/(\S.*?\w)\/\//is',				// //...//
				'/\[i\](.*?)\[\/i\]/is',				// [i]...[/i]
				'/__(\S.*?\S)__/is',					// __...__
				'/\[u\](.*?)\[\/u\]/is',				// [u]...[/u]
				'/\[color=([^\]]+?)\](.*?)\[\/color\]/is',	// [color=<color>]...[/color]
				'/\[new\]/ie',							// [new]
				'/\[popular\]/ie',						// [popular]
				'/\[flag=([^\]]+?)\]/ie',				// [flag=<flag>]
				'/\[flag\](.*?)\[\/flag\]/ise', 		// [flag]...[/flag]
				'/\[list\](.*?)\[\/list\]/ise', 		// [list]...[/list]
				'/\[list=([^\]]+?)\](.*?)\[\/list\]/ise',	// [list=1]...[/list]
				'/\n\n+[ \t]*\[\*\][ \t]*/ie',			// [*] (outside [list]...[/list])
				'/\n?[ \t]*\[\*\][ \t]*/ie',
				'/\[li\](.*?)\[\/li\]/is',				// [li]...[/li] (outside [list]...[/list])
				'/\[chart=([^\]]+?)\](.*?)\[\/chart\]/ise',	// [chart=<width>, <height>, <params>]...[/chart]
				'/\[embed=([^\]]+?)\]/ie',					// [embed=<id>, <width>, <height>, <params>] or [embed=<id>, window]
				'/\[flash=([^\]]+?)\]/ie',					// [flash=<id>, <width>, <height>, <params>] or [flash=<id>, window]
				'/\[sound=([^\]]+?)\]/ie',					// [sound=<id>]
				'/\[go=([^\]]+?)\]/ie', 					// [go=<name>]
				'/\[\[([^\]]+?)\]\]/ie', 					// [[<name>]]
				'/\[article\.description=([^\]]+?)\]/ie',	// [article.description=<id>]
				'/\[article=([^\]]+?)\]/ie',				// [article=<id>] or [article=<id>, title]
				'/\[next=([^\]]+?)\]/ie',					// [next=<id>]
				'/\[previous=([^\]]+?)\]/ie',				// [previous=<id>]
				'/\[random\]/ie',							// [random]
				'/\[random\.description=([^\]]+?)\]/ie',	// [random.description=section:<id>]
				'/\[random=([^\]]+?)\]/ie',					// [random=section:<id>] or [random=category:<id>]
				'/\[form=([^\]]+?)\]/ie',					// [form=<id>] or [form=<id>, title]
				'/\[section=([^\]]+?)\]/ie',				// [section=<id>] or [section=<id>, title]
				'/\[category\.description=([^\]]+?)\]\n*/ise',	// [category.description=<id>]
				'/\[category=([^\]]+?)\]/ie',				// [category=<id>] or [category=<id>, title]
				'/\[user=([^\]]+?)\]/ie',					// [user=<id>] or [user=<id>, title]
				'/\[server=([^\]]+?)\]/ie', 				// [server=<id>]
				'/\[file=([^\]]+?)\]/ie',					// [file=<id>] or [file=<id>, title]
				'/\[download=([^\]]+?)\]/ie',				// [download=<id>] or [download=<id>, title]
				'/\[action=([^\]]+?)\]/ie', 				// [action=<id>]
				'/\[comment=([^\]]+?)\]/ie',				// [comment=<id>] or [comment=<id>, title]
				'/\[decision=([^\]]+?)\]/ie',				// [decision=<id>] or [decision=<id>, title]
				'/\[url=([^\]]+?)\](.*?)\[\/url\]/ise', 	// [url=url]label[/url] (deprecated by [link])
				'/\[url\](.*?)\[\/url\]/ise',				// [url]url[/url] (deprecated by [link])
				'/\[link=([^\]]+?)\](.*?)\[\/link\]/ise',	// [link=label]url[/link]
				'/\[link\](.*?)\[\/link\]/ise', 			// [link]url[/link]
				'/\[button=([^\]]+?)\](.*?)\[\/button\]/ise',	// [button=label]url[/button]
				'/\[button=([^\|]+?)\|([^\]]+?)]/ise',		// [button=label|url]
				'/\[click=([^\|]+?)\|([^\]]+?)]/ise',		// [click=label|url]
				'/\[clicks=([^\]]+?)]/ise',					// [clicks=url]
				'/\[script\](.*?)\[\/script\]/ise', 		// [script]url[/script]
				'/\[menu\](.*?)\[\/menu\]\n*/ise',			// [menu]url[/menu]
				'/\[menu=([^\]]+?)\](.*?)\[\/menu\]\n{0,1}/ise',	// [menu=label]url[/menu]
				'/\[submenu\](.*?)\[\/submenu\]\n{0,1}/ise',	// [submenu]url[/submenu]
				'/\[submenu=([^\]]+?)\](.*?)\[\/submenu\]\n*/ise', // [submenu=label]url[/submenu]
				'/\[email=([^\]]+?)\](.*?)\[\/email\]/ise', // [email=label]url[/email]
				'/\[email\](.*?)\[\/email\]/ise',			// [email]url[/email]
				'/\[([^ ][^\]\|]+?[^ ])\|([^ ][^\]]+?[^ ])\]/ise',			// [label|url]
				'/\[question\](.*?)\[\/question\]\n*/ise',	// [question]...[/question]
				'/\[question\]/ise',						// [question]
				'/\[answer\]/ise',							// [answer]
				'/\[newsfeed=([^\]]+?)\]/ise',				// [newsfeed=url]
				'/\[newsfeed\.([^=\]]+?)=([^\]]+?)\]/ise',	// [newsfeed.variant=url]
				'/\[twitter=([^\]]+?)\]/ise',				// [twitter=id]
				'/\[tsearch=([^\]]+?)\]/ise',				// [tsearch=id]
				'/\[retweet\]/ise',							// [retweet]
				'/\[iframe\](.*?)\[\/iframe\]/ise',			// [iframe]<url>[/iframe]
				'/\[iframe=([^\]]+?)\](.*?)\[\/iframe\]/ise',	// [iframe=<width>, <height>]<url>[/iframe]
				'/\[scroller\](.*?)\[\/scroller\]/ise', 	// [scroller]...[/scroller]
				'/\[toq\]\n*/ise',							// [toq] (table of questions)
				'/\[title\](.*?)\[\/title\]\n*/is', 		// [title]...[/title]
				'/\[subtitle\](.*?)\[\/subtitle\]\n*/is',	// [subtitle]...[/subtitle]
				'/\[(header[1-5])\](.*?)\[\/\1\]\n*/ise',	// [header1]...[/header1] ... [header5]...[/header5]
				'/^======(\S.*?\S)======/me',				// ======...====== level 5 headline
				'/<(br \/|p)>======(\S.*?\S)======<(br \/|\/p)>/me',		// ======...====== level 5 headline
				'/^=====(\S.*?\S)=====/me',					// =====...===== level 4 headline
				'/<(br \/|p)>=====(\S.*?\S)=====<(br \/|\/p)>/me',			// =====...===== level 4 headline
				'/^====(\S.*?\S)====/me',					// ====...==== level 3 headline
				'/<(br \/|p)>====(\S.*?\S)====<(br \/|\/p)>/me',			// ====...==== level 3 headline
				'/^===(\S.*?\S)===/me',						// ===...=== level 2 headline
				'/<(br \/|p)>===(\S.*?\S)===<(br \/|\/p)>/me',				// ===...=== level 2 headline
				'/^==(\S.*?\S)==/me',						// ==...== level 1 headline
				'/<(br \/|p)>==(\S.*?\S)==<(br \/|\/p)>/me',				// ==...== level 1 headline
				'/\[toc\]\n*/ise',							// [toc] (table of content)
				'/\[published\.([^\]=]+?)=([^\]]+?)\]\n*/ise',	// [published.decorated=section:4029]
				'/\[published\.([^\]]+?)\]\n*/ise',			// [published.decorated]
				'/\[published=([^\]]+?)\]\n*/ise',			// [published=section:4029]
				'/\[published\]\n*/ise',					// [published]
				'/\[read\.([^\]=]+?)=([^\]]+?)\]\n*/ise',	// [read.decorated=section:4029]
				'/\[read\.([^\]]+?)\]\n*/ise',				// [read.decorated]
				'/\[read=([^\]]+?)\]\n*/ise',				// [read=section:4029]
				'/\[read\]\n*/ise', 						// [read]
				'/\[updated\.([^\]=]+?)=([^\]]+?)\]\n*/ise', // [updated.simple=section:4029] (a list of recent updates)
				'/\[updated\.([^\]]+?)\]\n*/ise', 			// [updated.simple] (a list of recent updates)
				'/\[updated=([^\]]+?)\]\n*/ise', 			// [updated=section:4029] (a compact list of recent updates)
				'/\[updated\]\n*/ise',						// [updated] (a compact list of recent updates)
				'/\[voted\.([^\]=]+?)=([^\]]+?)\]\n*/ise',	// [voted.decorated=section:4029]
				'/\[voted\.([^\]]+?)\]\n*/ise',				// [voted.decorated]
				'/\[voted=([^\]]+?)\]\n*/ise',				// [voted=section:4029]
				'/\[voted\]\n*/ise', 						// [voted]
				'/\[freemind\]\n*/ise', 					// [freemind] (a mind map of site content)
				'/\[freemind=([^\]]+?)\]\n*/ise',			// [freemind=section:4029] (a mind map of section content)
				'/\[sections\]\n*/ise',						// [sections] (site map)
				'/\[sections\.([^\]=]+?)\]\n*/ise',			// [sections.folded] (site map)
				'/\[sections=([^\]]+?)\]\n*/ise',			// [sections=section:4029] (sub-sections)
				'/\[sections\.([^\]=]+?)=([^\]]+?)\]\n*/ise',	// [sections.simple=self] (assigned)
				'/\[categories\]\n*/ise',					// [categories] (category tree)
				'/\[categories\.([^\]=]+?)\]\n*/ise',		// [categories.folded] (category tree)
				'/\[categories=([^\]]+?)\]\n*/ise',			// [categories=section:4029] (sub-categories)
				'/\[categories\.([^\]=]+?)=([^\]]+?)\]\n*/ise',	// [categories.simple=self] (assigned)
				'/\[calendar\]\n*/ise',					// [calendar]
				'/\[calendar=([^\]]+?)\]\n*/ise',		// [calendar=section:4029]
				'/\[users=([^\]]+?)\]/ie',					// [users=present]
				'/\[news=([^\]]+?)\]/ise',				// [news=flash]
				'/\[table=([^\]]+?)\]/ise', 			// [table=<id>]
				'/\[table\.([^=\]]+?)=([^\]]+?)\]/ise', // [table.json=<id>]  [table.timeplot=<id>]
				'/\[locations=([^\]]+?)\]/ise', 		// [locations=<id>]
				'/\[location=([^\]]+?)\]/ise',			// [location=<id>]
				'/\[wikipedia=([^\]]+?)\]/ise', 		// [wikipedia=keyword] or [wikipedia=keyword, title]
				'/\[digraph\](.*?)\[\/digraph\]/ise',	// [digraph]url[/digraph]
				'/\[be\]/i',							// [be] belgian flag
				'/\[ca\]/i',							// [ca] canadian flag
				'/\[ch\]/i',							// [ch] swiss flag
				'/\[de\]/i',							// [de] german flag
				'/\[en\]/i',							// [en] english flag
				'/\[es\]/i',							// [es] spanish flag
				'/\[fr\]/i',							// [fr] french flag
				'/\[gb\]/i',							// [gb] gb flag
				'/\[gr\]/i',							// [gr] greek flag
				'/\[it\]/i',							// [it] italian flag
				'/\[pt\]/i',							// [pt] portuguese flag
				'/\[us\]/i',							// [pt] us flag
				'/\[clear\]\n*/i',						// [clear]
				'/\[nl\]\n*/si',						// [nl] (after tables)
				'/\[br\]/i' 							// [br] (deprecated by [nl])
			);
		}

		// initialize only once
		static $replace;
		if(!isset($replace)) {
			$replace = array(
				'',																// delete HTML comments
				"Codes::render_escaped(Codes::fix_tags('$1'))",						// [escape]...[/escape]
				"Codes::render_pre(Codes::fix_tags('$1'), 'php')",					// [php]...[/php]
				"Codes::render_pre(Codes::fix_tags('$1'), 'snippet')",				// [snippet]...[/snippet]
				'', 																// [page]
				"Codes::render_hidden(Codes::fix_tags('$1'), 'hidden')",			// [hidden]...[/hidden]
				"Codes::render_hidden(Codes::fix_tags('$1'), 'restricted')",		// [restricted]...[/restricted]
				"Codes::render_hidden(Codes::fix_tags('$1'), 'anonymous')",			// [anonymous]...[/anonymous]
				"Codes::get_parameter('\\1')",										// [parameter=<name>]
				"i18n::filter(Codes::fix_tags('$2'), '$1')", 						// [lang=xy]...[/lang]
				"utf8::encode(str_replace('$1', '|', utf8::from_unicode(Codes::fix_tags('$2'))))",	// [csv=;]...[/csv]
				"str_replace(',', '|', Codes::fix_tags('$1'))",						// [csv]...[/csv]
				"Codes::render_static_table(Codes::fix_tags('$2'), '$1')",			// [table=variant]...[/table]
				"Codes::render_static_table(Codes::fix_tags('$1'), '')",			// [table]...[/table]
				"Codes::render_object('images', '$1')",								// [images=<ids>]
				"'<div class=\"external_image\"><img src=\"'.encode_link('$1').'\" alt=\"\" /></div>'",	// [image]src[/image]
				"'<div class=\"external_image\"><img src=\"'.encode_link('$2').'\" alt=\"'.encode_link('$1').'\" /></div>'", // [image=alt]src[/image]
				"'<div class=\"external_image\"><img src=\"'.encode_link('$1').'\" alt=\"\" /></div>'",	// [img]src[/img]
				"'<div class=\"external_image\"><img src=\"'.encode_link('$2').'\" alt=\"'.encode_link('$1').'\" /></div>'", // [img=alt]src[/img]
				"Codes::render_object('image', Codes::fix_tags('$1'))",				// [image=<id>]
				'<code>\\1</code>', 												// ##...##
				'<code>\\1</code>', 												// [code]...[/code]
				"Skin::build_block(Codes::fix_tags('$1'), 'indent')", 				// [indent]...[indent]
				"Skin::build_block(Codes::fix_tags('$1'), 'quote')",				// [quote]...[/quote]
				"Skin::build_box('$1', Codes::fix_tags('$2'), 'folded')",			// [folded=title]...[/folded]
				"Skin::build_box(NULL, Codes::fix_tags('$1'), 'folded')", 			// [folded]...[/folded]
				"Skin::build_box('$1', Codes::fix_tags('$2'), 'folded')",			// [folder=title]...[/folder]
				"Skin::build_box(NULL, Codes::fix_tags('$1'), 'folded')", 			// [folder]...[/folder]
				"Skin::build_box('$1', Codes::fix_tags('$2'), 'unfolded')",			// [unfolded=title]...[/unfolded]
				"Skin::build_box(NULL, Codes::fix_tags('$1'), 'unfolded')", 		// [unfolded]...[/unfolded]
				"Skin::build_box('$1', Codes::fix_tags('$2'), 'sidebar')",			// [sidebar=title]...[/sidebar]
				"Skin::build_box(NULL, Codes::fix_tags('$1'), 'sidebar')",			// [sidebar]...[/sidebar]
				"Skin::build_block(Codes::fix_tags('$1'), 'note')",					// [note]...[/note]
				"Skin::build_block(Codes::fix_tags('$1'), 'caution')",				// [caution]...[/caution]
				"Skin::build_block('$1', 'search')",								// [search=<words>]
				"Skin::build_block(NULL, 'search')",								// [search]
				"Codes::render_cloud('$1')",										// [cloud=12]
				"Codes::render_cloud(20)",											// [cloud]
				"Codes::render_collections()",										// [collections]
				'', 																// [login=<words>] --obsoleted
				'', 																// [login] --obsoleted
				"Skin::build_block(Codes::fix_tags('$1'), 'center')", 				// [center]...[/center]
				"Skin::build_block(Codes::fix_tags('$1'), 'right')",				// [right]...[/right]
				"Skin::build_block(Codes::fix_tags('$1'), 'decorated')",			// [decorated]...[/decorated]
				"Skin::build_block(Codes::fix_tags('$2'), '$1')", 					// [style=variant]...[/style]
				'<acronym title="\\1">\\2</acronym>',								// [hint=help]...[/hint]
				"Skin::build_block(Codes::fix_tags('$1'), 'tiny')",					// [tiny]...[/tiny]
				"Skin::build_block(Codes::fix_tags('$1'), 'small')",				// [small]...[/small]
				"Skin::build_block(Codes::fix_tags('$1'), 'big')",					// [big]...[/big]
				"Skin::build_block(Codes::fix_tags('$1'), 'huge')",					// [huge]...[/huge]
				'<sub>\\1</sub>',													// [subscript]...[/subscript]
				'<sup>\\1</sup>',													// [superscript]...[/superscript]
				'<ins>\\1</ins>',													// ++...++
				"HORIZONTAL_RULER", 												// [---], [___]
				"HORIZONTAL_RULER", 												// ----
				'<ins>\\1</ins>',													// [inserted]...[/inserted]
				' <del>\\1</del>',													// --...--
				'<del>\\1</del>',													// [deleted]...[/deleted]
				'<b>\\1</b>',														// **...**
				'<b>\\1</b>',														// [b]...[/b]
				' <i>\\1</i>',														// //...//
				'<i>\\1</i>',														// [i]...[/i]
				'<span style="text-decoration: underline">\\1</span>',				// __...__
				'<span style="text-decoration: underline">\\1</span>',				// [u]...[/u]
				'<span style="color: \\1">\\2</span>',								// [color]...[/color]
				"NEW_FLAG", 														// [new]
				"POPULAR_FLAG", 													// [popular]
				"Skin::build_flag('\\1')",											// [flag=....]
				"Skin::build_flag('\\1')",											// [flag]...[/flag]
				"Codes::render_list(Codes::fix_tags('$1'), NULL)",					// [list]...[/list]
				"Codes::render_list(Codes::fix_tags('$2'), '$1')",					// [list=?]...[/list]
				"BR.BR.BULLET_IMG.'&nbsp;'",										// standalone [*]
				"BR.BULLET_IMG.'&nbsp;'",
				'<li>\\1</li>', 													// [li]...[/li]
				"Codes::render_chart(Codes::fix_tags('$2'), '$1')",					// [chart=<width>, <height>, <params>]...[/chart]
				"Codes::render_embed(Codes::fix_tags('$1'))",						// [embed=<id>, <width>, <height>, <params>]
				"Codes::render_embed(Codes::fix_tags('$1'))",						// [flash=<id>, <width>, <height>, <params>] -- obsoleted by 'embed'
				"Codes::render_object('sound', Codes::fix_tags('$1'))",				// [sound=<id>]
				"Codes::render_object('go', Codes::fix_tags('$1'))",				// [go=<name>]
				"Codes::render_object('go', Codes::fix_tags('$1'))",				// [[<name>]]
				"Codes::render_object('article.description', Codes::fix_tags('$1'))",// [article.description=<id>]
				"Codes::render_object('article', Codes::fix_tags('$1'))",			// [article=<id>]
				"Codes::render_object('next', Codes::fix_tags('$1'))",				// [next=<id>]
				"Codes::render_object('previous', Codes::fix_tags('$1'))",			// [previous=<id>]
				"Codes::render_random()",											// [random]
				"Codes::render_random('$1', 'description')",						// [random.description=section:<id>]
				"Codes::render_random('$1')",										// [random=section:<id>]
				"Codes::render_object('form', Codes::fix_tags('$1'))",				// [form=<id>]
				"Codes::render_object('section', Codes::fix_tags('$1'))",			// [section=<id>]
				"Codes::render_object('category.description', '$1')", 				// [category.description=<id>]
				"Codes::render_object('category', Codes::fix_tags('$1'))",	 		// [category=<id>]
				"Codes::render_object('user', Codes::fix_tags('$1'))",				// [user=<id>]
				"Codes::render_object('server', Codes::fix_tags('$1'))",			// [server=<id>]
				"Codes::render_object('file', Codes::fix_tags('$1'))",				// [file=<id>] or [file=<id>, title]
				"Codes::render_object('download', Codes::fix_tags('$1'))",			// [download=<id>] or [download=<id>, title]
				"Codes::render_object('action', Codes::fix_tags('$1'))",			// [action=<id>]
				"Codes::render_object('comment', Codes::fix_tags('$1'))",			// [comment=<id>] or [comment=<id>, title]
				"Codes::render_object('decision', Codes::fix_tags('$1'))", 			// [decision=<id>] or [decision=<id>, title]
				"Skin::build_link(encode_link('$1'), Codes::fix_tags('$2'))",		// [url=url]label[/link] (deprecated by [link])
				"Skin::build_link(encode_link('$1'), NULL)",						// [url]url[/url] (deprecated by [link])
				"Skin::build_link(encode_link('$2'), Codes::fix_tags('$1'))",		// [link=label]url[/link]
				"Skin::build_link(encode_link('$1'), NULL)",						// [link]url[/link]
				"Skin::build_link(encode_link('$2'), Codes::fix_tags('$1'), 'button')",	// [button=label]url[/button]
				"Skin::build_link(encode_link('$2'), Codes::fix_tags('$1'), 'button')",	// [button=label|url]
				"Skin::build_link(encode_link('$2'), Codes::fix_tags('$1'), 'click')",	// [click=label|url]
				"Codes::render_clicks('$1')",										// [clicks=url]
				"Skin::build_link(encode_link('$1'), '$1', 'script')",				// [script]url[/script]
				"Skin::build_link(encode_link('$1'), '$1', 'menu_1')",				// [menu]url[/menu]
				"Skin::build_link(encode_link('$2'), Codes::fix_tags('$1'), 'menu_1')",	// [menu=label]url[/menu]
				"Skin::build_link(encode_link('$1'), '$1', 'menu_2')",				// [submenu]url[/submenu]
				"Skin::build_link(encode_link('$2'), Codes::fix_tags('$1'), 'menu_2')",	// [submenu=label]url[/submenu]
				"Codes::render_email(encode_link('$2'), Codes::fix_tags('$1'))",	// [email=label]url[/email]
				"Codes::render_email(encode_link('$1'), '$1')",						// [email]url[/email]
				"Skin::build_link(encode_link('$2'), Codes::fix_tags('$1'))",		// [label|url]
				"Codes::render_title(Codes::fix_tags('$1'), 'question')", 			// [question]...[/question]
				"QUESTION_FLAG",													// [question]
				"ANSWER_FLAG",														// [answer]
				"Codes::render_newsfeed('$1', 'ajax')",								// [newsfeed=url]
				"Codes::render_newsfeed('$2', '$1')",								// [newsfeed=url]
				"Codes::render_twitter('$1')",										// [twitter=id]
				"Codes::render_twitter_search('$1')",								// [tsearch=id]
				"Codes::render_retweet()",											// [retweet]
				"Codes::render_iframe(Codes::fix_tags('$1'), '500, 320')",			// [iframe]<url>[/iframe]
				"Codes::render_iframe(Codes::fix_tags('$2'), '$1')",				// [iframe=<width>, <height>]<url>[/iframe]
				"Codes::render_animated(Codes::fix_tags('$1'), 'scroller')",		// [scroller]...[/scroller]
				"Codes::render_table_of('questions')",								// [toq]
				'[header1]\\1[/header1]',											// [title]...[/title]
				'[header2]\\1[/header2]',											// [subtitle]...[/subtitle]
				"Codes::render_title(Codes::fix_tags('$2'), '$1')",					// [header1]...[/header1] ... [header5]...[/header5]
				"Codes::render_title(Codes::fix_tags('$1'), 'header5')",			// ======...====== level 5 header
				"Codes::render_title(Codes::fix_tags('$2'), 'header5')",			// ======...====== level 5 header
				"Codes::render_title(Codes::fix_tags('$1'), 'header4')",			// =====...===== level 4 header
				"Codes::render_title(Codes::fix_tags('$2'), 'header4')",			// =====...===== level 4 header
				"Codes::render_title(Codes::fix_tags('$1'), 'header3')",			// ====...==== level 3 header
				"Codes::render_title(Codes::fix_tags('$2'), 'header3')",			// ====...==== level 3 header
				"Codes::render_title(Codes::fix_tags('$1'), 'header2')",			// ===...=== level 2 header
				"Codes::render_title(Codes::fix_tags('$2'), 'header2')",			// ===...=== level 2 header
				"Codes::render_title(Codes::fix_tags('$1'), 'header1')",			// ==...== level 1 header
				"Codes::render_title(Codes::fix_tags('$2'), 'header1')",			// ==...== level 1 header
				"Codes::render_table_of('content')",								// [toc]
				"Codes::render_published('$2', '$1')",								// [published.decorated=section:4029]
				"Codes::render_published('', '$1')",								// [published.decorated]
				"Codes::render_published('$1', 'simple')",							// [published=section:4029]
				"Codes::render_published('', 'simple')",							// [published]
				"Codes::render_read('$2', '$1')",									// [read.decorated=section:4029]
				"Codes::render_read('', '$1')",										// [read.decorated]
				"Codes::render_read('$1', 'hits')",									// [read=section:4029]
				"Codes::render_read('', 'hits')",									// [read]
				"Codes::render_updated('$2', '$1')",								// [updated.simple=section:4029]
				"Codes::render_updated('', '$1')",									// [updated.simple]
				"Codes::render_updated('$1', 'simple')",							// [updated=section:4029]
				"Codes::render_updated('', 'simple')",								// [updated]
				"Codes::render_voted('$2', '$1')",									// [voted.decorated=section:4029]
				"Codes::render_voted('', '$1')",									// [voted.decorated]
				"Codes::render_voted('$1', 'simple')",								// [voted=section:4029]
				"Codes::render_voted('', 'simple')",								// [voted]
				"Codes::render_freemind('sections')",								// [freemind]
				"Codes::render_freemind('$1')", 									// [freemind=section:4029] or [freemind=123]
				"Codes::render_sections()", 										// [sections] (site map)
				"Codes::render_sections('', '$1')",									// [sections.folded] (site map)
				"Codes::render_sections('$1')", 									// [sections=section:4029] (sub-sections)
				"Codes::render_sections('$2', '$1')",								// [sections.simple=self] (assigned)
				"Codes::render_categories()", 										// [categories] (category tree)
				"Codes::render_categories('', '$1')",								// [categories.folded] (category tree)
				"Codes::render_categories('$1')", 									// [categories=category:4029] (sub-categories)
				"Codes::render_categories('$2', '$1')",								// [categories.simple=self] (assigned)
				"Codes::render_calendar()", 										// [calendar]
				"Codes::render_calendar('$1')", 									// [calendar=section:4029]
				"Codes::render_users('$1')", 										// [users=present]
				"Codes::render_news('$1')", 										// [news=flash]
				"Codes::render_dynamic_table('$1')",								// [table=<id>]
				"Codes::render_dynamic_table('$2', '$1')",							// [table.json=<id>] [table.timeplot=<id>]
				"Codes::render_locations('$1')",									// [locations=<id>]
				"Codes::render_location('$1')",										// [location=<id>]
				"Codes::render_wikipedia(Codes::fix_tags('$1'))",					// [wikipedia=keyword] or [wikipedia=keyword, title]
				"Codes::render_graphviz('$1', 'digraph')",							// [digraph]...[/digraph]
				' <img src="'.$context['url_to_root'].'skins/_reference/flags/be.gif" alt="" /> ', // [be] belgian flag
				' <img src="'.$context['url_to_root'].'skins/_reference/flags/ca.gif" alt="" /> ', // [ca] canadian flag
				' <img src="'.$context['url_to_root'].'skins/_reference/flags/ch.gif" alt="" /> ', // [ch] swiss flag
				' <img src="'.$context['url_to_root'].'skins/_reference/flags/de.gif" alt="" /> ', // [de] german flag
				' <img src="'.$context['url_to_root'].'skins/_reference/flags/gb.gif" alt="" /> ', // [en] english flag
				' <img src="'.$context['url_to_root'].'skins/_reference/flags/es.gif" alt="" /> ', // [es] spanish flag
				' <img src="'.$context['url_to_root'].'skins/_reference/flags/fr.gif" alt="" /> ', // [fr] french flag
				' <img src="'.$context['url_to_root'].'skins/_reference/flags/gb.gif" alt="" /> ', // [gb] english flag
				' <img src="'.$context['url_to_root'].'skins/_reference/flags/gr.gif" alt="" /> ', // [gr] greek flag
				' <img src="'.$context['url_to_root'].'skins/_reference/flags/it.gif" alt="" /> ', // [it] italian flag
				' <img src="'.$context['url_to_root'].'skins/_reference/flags/pt.gif" alt="" /> ', // [pt] portuguese flag
				' <img src="'.$context['url_to_root'].'skins/_reference/flags/us.gif" alt="" /> ', // [us] us flag
				' <br style="clear: both;" /> ',									// [clear]
				BR, 																// [nl]
				BR																	// [br] (deprecated by [nl])
			);
		}

		// include other codes from plugins
		$dir = $context['path_to_root'].'codes/extensions/';
    if ($handle = opendir($dir)) {

        while (false !== ($file = readdir($handle))) {
          if ($file == '..')
            continue;

          if ($file == '.')
            continue;

          include_once($dir.$file);
        }

        closedir($handle);
    }

		// ensure we have enough time to execute
		Safe::set_time_limit(30);

		// do it globally
		$text = preg_replace($pattern, $replace, $text);

		// FCKEditor optimisation
		$text = str_replace("</pre>\n<pre>", "\n", $text);

		// done
		return $text;

	}

	/**
	 * render an animated block of text
	 *
	 * @param string the text
	 * @param string the variant
	 * @return string the rendered text
	**/
	function &render_animated($text, $variant) {
		global $context, $scroller_counter;

		$scroller_counter++;
		$output = '<marquee id="scroller_'.$scroller_counter.'">'.$text.'</marquee>';
		return $output;
	}

	/**
	 * render a calendar
	 *
	 * The provided anchor can reference:
	 * - a section 'section:123'
	 * - nothing
	 *
	 * @param string the anchor (e.g. 'section:123')
	 * @return string the rendered text
	**/
	function &render_calendar($anchor='') {
		global $context;

		// a list of dates
		include_once $context['path_to_root'].'dates/dates.php';

		// sanity check
		$anchor = trim($anchor);

		// get records
		if(strpos($anchor, 'section:') === 0)
			$items =& Dates::list_for_prefix(NULL, 'compact', $anchor);
		else
			$items =& Dates::list_for_prefix(NULL, 'compact', NULL);

		// build calendar for current month
		$text =& Dates::build_months($items, FALSE, TRUE, FALSE, TRUE, gmstrftime('%Y'), gmstrftime('%m'), 'compact calendar');

		// job done
		return $text;
	}

	/**
	 * render a list of categories
	 *
	 * The provided anchor can reference:
	 * - a section 'category:123'
	 * - a user 'user:789'
	 * - 'self'
	 * - nothing
	 *
	 * @param string the anchor (e.g. 'section:123')
	 * @param string layout to use
	 * @return string the rendered text
	**/
	function &render_categories($anchor='', $layout='compact') {
		global $context;

		// we return some text;
		$text = '';

		// number of items to display
		$count = YAHOO_LIST_SIZE;
		if(($position = strpos($anchor, ',')) !== FALSE) {
			$count = (integer)trim(substr($anchor, $position+1));
			if(!$count)
				$count = YAHOO_LIST_SIZE;

			$anchor = trim(substr($anchor, 0, $position));
		}

		// scope is limited to current surfer
		if(($anchor == 'self') && Surfer::get_id()) {
			$anchor = 'user:'.Surfer::get_id();

			// refresh on every page load
			Cache::poison();

		}

		// scope is limited to one category
		if(strpos($anchor, 'category:') === 0)
			$text =& Categories::list_by_title_for_anchor($anchor, 0, $count, $layout);

		// scope is limited to one author
		elseif(strpos($anchor, 'user:') === 0)
			$text =& Members::list_categories_by_title_for_member($anchor, 0, $count, $layout);

		// consider all pages
		if(!$text)
			$text =& Categories::list_by_title_for_anchor(NULL, 0, $count, $layout);

		// we have an array to format
		if(is_array($text))
			$text =& Skin::build_list($text, $layout);

		// job done
		return $text;
	}

	/**
	 * render a chart
	 *
	 * @param string chart data, in JSON format
	 * @param string chart parameters
	 * @return string the rendered text
	**/
	function &render_chart($data, $variant) {
		global $context;

		// split parameters
		$attributes = preg_split("/\s*,\s*/", $variant, 4);

		// set a default size
		if(!isset($attributes[0]))
			$attributes[0] = 320;
		if(!isset($attributes[1]))
			$attributes[1] = 240;

		// object attributes
		$width = $attributes[0];
		$height = $attributes[1];
		$flashvars = '';
		if(isset($attributes[2]))
			$flashvars = $attributes[2];

		// allow several charts to co-exist in the same page
		static $chart_index;
		if(!isset($chart_index))
			$chart_index = 1;
		else
			$chart_index++;

		$url = $context['url_to_home'].$context['url_to_root'].'included/browser/open-flash-chart.swf';
		$text = '<div id="open_flash_chart_'.$chart_index.'" class="no_print">Flash plugin or Javascript are turned off. Activate both and reload to view the object</div>'."\n"
			.JS_PREFIX
			.'var params = {};'."\n"
			.'params.base = "'.dirname($url).'/";'."\n"
			.'params.quality = "high";'."\n"
			.'params.wmode = "opaque";'."\n"
			.'params.allowscriptaccess = "always";'."\n"
			.'params.menu = "false";'."\n"
			.'params.flashvars = "'.$flashvars.'";'."\n"
			.'swfobject.embedSWF("'.$url.'", "open_flash_chart_'.$chart_index.'", "'.$width.'", "'.$height.'", "6", "'.$context['url_to_home'].$context['url_to_root'].'included/browser/expressinstall.swf", {"get-data":"open_flash_chart_'.$chart_index.'"}, params);'."\n"
			."\n"
			.'var chart_data_'.$chart_index.' = '.trim(str_replace(array('<br />', "\n"), ' ', $data)).';'."\n"
			."\n"
			.'function open_flash_chart_'.$chart_index.'() {'."\n"
			.'	return Object.toJSON(chart_data_'.$chart_index.');'."\n"
			.'}'."\n"
			.JS_SUFFIX;

		return $text;

	}

	/**
	 * list clicks
	 *
	 * @param string web address that is monitored
	 * @return string the rendered text
	**/
	function &render_clicks($url) {
		global $context;

		$text = '';

		// sanity check
		if(!$url)
			return $text;

		// if we received only an id, assume file access
		if(preg_match('/^[0-9]+$/', $url))
			$url = 'file:'.$url;

		// the list of people who have followed this link
		include_once $context['path_to_root'].'users/activities.php';
		if($users = Activities::list_at($url, array('click', 'fetch'), 50, 'comma')) {

			$count = Activities::count_at($url, array('click', 'fetch'));
			$text .= sprintf(i18n::ns('%d named person has followed the link: %s', '%d named persons have followed the link: %s', $count), $count, $users);

		} else
			$text .= i18n::s('No authenticated person has used this link yet');

		return $text;

	}

	/**
	 * render the cloud of tags
	 *
	 * @param string the number of items to list
	 * @return string the rendered text
	**/
	function &render_cloud($count=40) {
		global $context;

		// sanity check
		if(!(int)$count)
			$count = 40;

		// query the database and layout that stuff
		if(!$text =& Members::list_categories_by_count_for_anchor(NULL, 0, $count, 'cloud'))
			$text = '<p>'.i18n::s('No item has been found.').'</p>';

		// we have an array to format
		if(is_array($text))
			$text =& Skin::build_list($text, '2-columns');

		// job done
		return $text;

	}

	/**
	 * list available collections
	 *
	 * @return string the rendered text
	**/
	function &render_collections() {
		global $context;

		// has one collection been defined?
		Safe::load('parameters/collections.include.php');
		if(!isset($context['collections']) || !is_array($context['collections'])) {
			$output = NULL;
			return $output;
		}

		// use attributes set for each collection
		$text = '';
		foreach($context['collections'] as $name => $attributes) {

			// retrieve collection information
			list($title, $path, $url, $introduction, $description, $prefix, $suffix, $visibility) = $attributes;

			// skip protected collections
			if(($visibility == 'N') && !Surfer::is_associate())
				continue;
			if(($visibility == 'R') && !Surfer::is_member())
				continue;

			// ensure we have a title for this collection
			if(!trim($title))
				$title = str_replace(array('.', '_', '%20'), ' ', $name);

			// build some hovering title
			$hover = ' title="'.encode_field(i18n::s('Access collection')." '".strip_tags($title)."'").'"';

			// signal restricted and private collections
			if($visibility == 'N')
				$title = PRIVATE_FLAG.$title;
			elseif($visibility == 'R')
				$title = RESTRICTED_FLAG.$title;

			// link to collection index page
			if($context['with_friendly_urls'] == 'Y')
				$link = 'collections/browse.php/'.rawurlencode($name);
			else
				$link = 'collections/browse.php?path='.urlencode($name);
			$text .= '<li><a href="'.$context['url_to_root'].$link.'"'.$hover.'>'.$title.'</a>';

			// add introduction text, if any
			if($introduction)
				$text .= ' - '.Codes::beautify($introduction);

			$text .= "</li>\n";
		}

		// finalize the list
		if($text)
			$text = '<ul class="collections">'."\n".$text."</ul>\n";

		// job done
		return $text;

	}

	/**
	 * render a dynamic table
	 *
	 * @param string the table content
	 * @param string the variant, if any
	 * @return string the rendered text
	**/
	function &render_dynamic_table($id, $variant='inline') {
		global $context;

		// refresh on every page load
		Cache::poison();

		// get actual content
		include_once $context['path_to_root'].'tables/tables.php';

		// use SIMILE Exhibit
		if($variant == 'filter') {

			// load the SIMILE Exhibit javascript library in shared/global.php
			$context['javascript']['exhibit'] = TRUE;

			// load data
			$context['page_header'] .= "\n".'<link href="'.$context['url_to_root'].Tables::get_url($id, 'fetch_as_json').'" type="application/json" rel="exhibit/data" />';

			// exhibit data in a table
			$text = '<div ex:role="exhibit-view" ex:viewClass="Exhibit.TabularView" ex:columns="'.Tables::build($id, 'json-labels').'" ex:columnLabels="'.Tables::build($id, 'json-titles').'" ex:border="0" ex:cellSpacing="0" ex:cellPadding="0" ex:showToolbox="true" ></div>'."\n";

			// allow for filtering
			$facets = '<div class="exhibit-facet">'
				.'<div class="exhibit-facet-header"><span class="exhibit-facet-header-title">'.i18n::s('Filter').'</span></div>'
				.'<div class="exhibit-facet-body-frame" style="margin: 0 2px 1em 0;">'
				.'<div ex:role="facet" ex:facetClass="TextSearch" style="display: block;"></div>'
				.'</div></div>';

			// facets from first columns
			$facets .= Tables::build($id, 'json-facets');

			// filter and facets aside
			$context['components']['boxes'] .= $facets;

		// build sparkline
		} elseif($variant == 'bars') {
			$text = '<img border="0" align="baseline" hspace="0" src="'.$context['url_to_root'].Tables::get_url($id, 'fetch_as_png').'&order=0&gap;0.5" alt="" />';

		// buid a Flash chart
		} elseif($variant == 'chart') {

			// split parameters
			$attributes = preg_split("/\s*,\s*/", $id, 4);

			// set a default size
			if(!isset($attributes[1]))
				$attributes[1] = 480;
			if(!isset($attributes[2]))
				$attributes[2] = 360;

			// object attributes
			$width = $attributes[1];
			$height = $attributes[2];
			$flashvars = '';
			if(isset($attributes[3]))
				$flashvars = $attributes[3];

			// allow several charts to co-exist in the same page
			static $chart_index;
			if(!isset($chart_index))
				$chart_index = 1;
			else
				$chart_index++;

			// get data in the suitable format
			$data = Tables::build($attributes[0], 'chart');

			// load it through Javascript
			$url = $context['url_to_home'].$context['url_to_root'].'included/browser/open-flash-chart.swf';
			$text = '<div id="table_chart_'.$chart_index.'" class="no_print">Flash plugin or Javascript are turned off. Activate both and reload to view the object</div>'."\n"
				.JS_PREFIX
				.'var params = {};'."\n"
				.'params.base = "'.dirname($url).'/";'."\n"
				.'params.quality = "high";'."\n"
				.'params.wmode = "opaque";'."\n"
				.'params.allowscriptaccess = "always";'."\n"
				.'params.menu = "false";'."\n"
				.'params.flashvars = "'.$flashvars.'";'."\n"
				.'swfobject.embedSWF("'.$url.'", "table_chart_'.$chart_index.'", "'.$width.'", "'.$height.'", "6", "'.$context['url_to_home'].$context['url_to_root'].'included/browser/expressinstall.swf", {"get-data":"table_chart_'.$chart_index.'"}, params);'."\n"
				."\n"
				.'var chart_data_'.$chart_index.' = '.trim(str_replace(array('<br />', "\n"), ' ', $data)).';'."\n"
				."\n"
				.'function table_chart_'.$chart_index.'() {'."\n"
				.'	return Object.toJSON(chart_data_'.$chart_index.');'."\n"
				.'}'."\n"
				.JS_SUFFIX;

		// build sparkline
		} elseif($variant == 'line') {
			$text = '<img border="0" align="baseline" hspace="0" src="'.$context['url_to_root'].Tables::get_url($id, 'fetch_as_png').'&order=2&gap=0.0" alt="" />';

		// we do the rendering ourselves
		} else
			$text = Tables::build($id, $variant);

		// put that into the web page
		return $text;
	}

	/**
	 * render an email address
	 *
	 * @param string the address
	 * @param string the label
	 * @return string the rendered text
	**/
	function &render_email($address, $text) {

		// be sure to display something
		if(!$text)
			$text = $address;

		// specify a scheme if not done yet
		if(!preg_match('/^[a-z]+:/i', $address))
			$address = 'mailto:'.$address;

		// return a complete anchor
		$output = Skin::build_link($address, $text, 'email');
		return $output;
	}

	/**
	 * embed an interactive object
	 *
	 * The id designates the target file.
	 * It can also include width and height of the target canvas, as in: '12, 100%, 250px'
	 *
	 * @param string id of the target file
	 * @return string the rendered string
	**/
	function &render_embed($id) {
		global $context;

		// split parameters
		$attributes = preg_split("/\s*,\s*/", $id, 4);
		$id = $attributes[0];

		// get the file
		if(!$item =& Files::get($id)) {
			$output = '[embed='.$id.']';
			return $output;
		}

		// stream in a separate page
		if(isset($attributes[1]) && preg_match('/window/i', $attributes[1])) {
			if(!isset($attributes[2]))
				$attributes[2] = i18n::s('Play in a separate window');
			$output = '<a href="'.$context['url_to_home'].$context['url_to_root'].Files::get_url($item['id'], 'stream', $item['file_name']).'" onclick="window.open(this.href); return false;" class="button"><span>'.$attributes[2].'</span></a>';
			return $output;
		}

		// file extension
		$extension = strtolower(substr($item['file_name'], -3));

		// set a default size
		if(!isset($attributes[1])) {
			if(!strcmp($extension, 'gan'))
				$attributes[1] = '98%';
			elseif(!strcmp($extension, 'mm') && isset($context['skins_freemind_canvas_width']))
				$attributes[1] = $context['skins_freemind_canvas_width'];
			else
				$attributes[1] = 480;
		}
		if(!isset($attributes[2])) {
			if(!strcmp($extension, 'gan'))
				$attributes[2] = '300px';
			elseif(!strcmp($extension, 'mm') && isset($context['skins_freemind_canvas_height']))
				$attributes[2] = $context['skins_freemind_canvas_height'];
			else
				$attributes[2] = 360;
		}

		// object attributes
		$width = $attributes[1];
		$height = $attributes[2];
		$flashvars = '';
		if(isset($attributes[3]))
			$flashvars = $attributes[3];

		// rendering depends on file extension
		switch($extension) {

		// stream a video
		case '3gp':
		case 'flv':
		case 'm4v':
		case 'mov':
		case 'mp4':

			// a flash player to stream a flash video
			$flvplayer_url = $context['url_to_home'].$context['url_to_root'].'included/browser/player_flv_maxi.swf';

			// file is elsewhere
			if(isset($item['file_href']) && $item['file_href'])
				$url = $item['file_href'];

			// prevent leeching (the flv player will provide session cookie, etc)
			else
				$url = $context['url_to_home'].$context['url_to_root'].Files::get_url($item['id'], 'fetch', $item['file_name']);

			// pass parameters to the player
			if($flashvars)
				$flashvars = str_replace('autostart=true', 'autoplay=1', $flashvars).'&';
			$flashvars .= 'width='.$width.'&height='.$height;

			// rely on Flash
			if(Surfer::has_flash()) {

				// the full object is built in Javascript --see parameters at http://flv-player.net/players/maxi/documentation/
				$output = '<div id="flv_'.$item['id'].'" class="no_print">Flash plugin or Javascript are turned off. Activate both and reload to view the object</div>'."\n"
					.JS_PREFIX
					.'var flashvars = { flv:"'.$url.'", '.str_replace(array('&', '='), array('", ', ':"'), $flashvars).'", autoload:0, margin:1, showiconplay:1, playeralpha:50, iconplaybgalpha:30, showloading:"always", ondoubleclick:"fullscreen" }'."\n"
					.'var params = { allowfullscreen: "true", allowscriptaccess: "always" }'."\n"
					.'var attributes = { id: "file_'.$item['id'].'", name: "file_'.$item['id'].'"}'."\n"
					.'swfobject.embedSWF("'.$flvplayer_url.'", "flv_'.$item['id'].'", "'.$width.'", "'.$height.'", "9", "'.$context['url_to_home'].$context['url_to_root'].'included/browser/expressinstall.swf", flashvars, params);'."\n"
					.JS_SUFFIX."\n";

			// native support
 			} else {

				// <video> is HTML5, <object> is legacy
 				$output = '<video width="'.$width.'" height="'.$height.'" autoplay="" controls="">'."\n"
					.'	<source src="'.$url.'" />'."\n"
					.'	<object width="'.$width.'" height="'.$height.'" data="'.$url.'" type="'.Files::get_mime_type($item['file_name']).'">'."\n"
					.'		<param value="'.$url.'" name="movie" />'."\n"
					.'		<param value="true" name="allowFullScreen" />'."\n"
					.'		<param value="always" name="allowscriptaccess" />'."\n"
					.'		<a href="'.$url.'">No video playback capabilities, please download the file</a>'."\n"
 					.'	</object>'."\n"
					.'</video>'."\n";

			}

			// job done
			return $output;

		// a ganttproject timeline
		case 'gan':

			// where the file is
			$path = 'files/'.$context['virtual_path'].str_replace(':', '/', $item['anchor']).'/'.rawurlencode($item['file_name']);

			// we actually use a transformed version of the file
			$cache_id = Cache::hash($path).'.xml';

			// apply the transformation
			if(!file_exists($context['path_to_root'].$cache_id) || (filemtime($context['path_to_root'].$cache_id) < filemtime($context['path_to_root'].$path)) || (!$text = Safe::file_get_contents($context['path_to_root'].$cache_id))) {

				// transform from GanttProject to SIMILE Timeline
				$text = Files::transform_gan_to_simile($path);

				// put in cache
				Safe::file_put_contents($cache_id, $text);

			}

			// load the SIMILE Timeline javascript library in shared/global.php
			$context['javascript']['timeline'] = TRUE;

			// cache would kill the loading of the library
			cache::poison();

			// 1 week ago
			$now = gmdate('M d Y H:i:s', time()-7*24*60*60);

			// load the right file
			$output = '<div id="gantt" style="height: '.$height.'; width: '.$width.'; border: 1px solid #aaa; font-family: Trebuchet MS, Helvetica, Arial, sans serif; font-size: 8pt"></div>'."\n"
				.JS_PREFIX
				.'var simile_handle;'."\n"
				.'function onLoad() {'."\n"
				.'  var eventSource = new Timeline.DefaultEventSource();'."\n"
				.'	var theme = Timeline.ClassicTheme.create();'."\n"
				.'            theme.event.bubble.width = 350;'."\n"
				.'            theme.event.bubble.height = 300;'."\n"
				.'  var bandInfos = ['."\n"
				.'    Timeline.createBandInfo({'."\n"
				.'        eventSource:    eventSource,'."\n"
				.'        date:           "'.$now.'",'."\n"
				.'        width:          "80%",'."\n"
				.'        intervalUnit:   Timeline.DateTime.WEEK,'."\n"
				.'        intervalPixels: 200,'."\n"
				.'		  theme:          theme,'."\n"
				.'        layout:         "original"  // original, overview, detailed'."\n"
				.'    }),'."\n"
				.'    Timeline.createBandInfo({'."\n"
				.'        showEventText: false,'."\n"
				.'        trackHeight: 0.5,'."\n"
				.'        trackGap: 0.2,'."\n"
				.'        eventSource:    eventSource,'."\n"
				.'        date:           "'.$now.'",'."\n"
				.'        width:          "20%",'."\n"
				.'        intervalUnit:   Timeline.DateTime.MONTH,'."\n"
				.'        intervalPixels: 50'."\n"
				.'    })'."\n"
				.'  ];'."\n"
				.'  bandInfos[1].syncWith = 0;'."\n"
				.'  bandInfos[1].highlight = true;'."\n"
				.'  bandInfos[1].eventPainter.setLayout(bandInfos[0].eventPainter.getLayout());'."\n"
				.'  simile_handle = Timeline.create(document.getElementById("gantt"), bandInfos, Timeline.HORIZONTAL);'."\n"
				.'	simile_handle.showLoadingMessage();'."\n"
				.'  Timeline.loadXML("'.$context['url_to_home'].$context['url_to_root'].$cache_id.'", function(xml, url) { eventSource.loadXML(xml, url); });'."\n"
				.'	simile_handle.hideLoadingMessage();'."\n"
				.'}'."\n"
				."\n"
				.'var resizeTimerID = null;'."\n"
				.'function onResize() {'."\n"
				.'    if (resizeTimerID == null) {'."\n"
				.'        resizeTimerID = window.setTimeout(function() {'."\n"
				.'            resizeTimerID = null;'."\n"
				.'            simile_handle.layout();'."\n"
				.'        }, 500);'."\n"
				.'    }'."\n"
				.'}'."\n"
				."\n"
				.'// observe page major events'."\n"
				.'Event.observe(window, "load", onLoad);'."\n"
				.'Event.observe(window, "resize", onResize);'."\n"
				.JS_SUFFIX;

			// job done
			return $output;

		// a Freemind map
		case 'mm':

			// if we have an external reference, use it
			if(isset($item['file_href']) && $item['file_href']) {
				$target_href = $item['file_href'];

			// else redirect to ourself
			} else {

				// ensure a valid file name
				$file_name = utf8::to_ascii($item['file_name']);

				// where the file is
				$path = 'files/'.$context['virtual_path'].str_replace(':', '/', $item['anchor']).'/'.rawurlencode($item['file_name']);

				// map the file on the regular web space
				$url_prefix = $context['url_to_home'].$context['url_to_root'];

				// redirect to the actual file
				$target_href = $url_prefix.$path;
			}

			// allow several viewers to co-exist in the same page
			static $freemind_viewer_index;
			if(!isset($freemind_viewer_index))
				$freemind_viewer_index = 1;
			else
				$freemind_viewer_index++;

			// load flash player
			$url = $context['url_to_home'].$context['url_to_root'].'included/browser/visorFreemind.swf';

			// variables
			$flashvars = 'initLoadFile='.$target_href.'&openUrl=_self';

			$output = '<div id="freemind_viewer_'.$freemind_viewer_index.'">Flash plugin or Javascript are turned off. Activate both and reload to view the object</div>'."\n"
				.JS_PREFIX
				.'var params = {};'."\n"
				.'params.base = "'.dirname($url).'/";'."\n"
				.'params.quality = "high";'."\n"
				.'params.wmode = "transparent";'."\n"
				.'params.menu = "false";'."\n"
				.'params.flashvars = "'.$flashvars.'";'."\n"
				.'swfobject.embedSWF("'.$url.'", "freemind_viewer_'.$freemind_viewer_index.'", "'.$width.'", "'.$height.'", "6", "'.$context['url_to_home'].$context['url_to_root'].'included/browser/expressinstall.swf", false, params);'."\n"
				.JS_SUFFIX."\n";

			// offer to download a copy of the map
			$menu = array($target_href => i18n::s('Browse this map with Freemind'));

			// display menu commands below the viewer
			$output .= Skin::build_list($menu, 'menu_bar');

			// job done
			return $output;

		// native flash
		case 'swf':

			// where to get the file
			if(isset($item['file_href']) && $item['file_href'])
				$url = $item['file_href'];

			// we provide the native file because of basename
			else
				$url = $context['url_to_home'].$context['url_to_root'].'files/'.str_replace(':', '/', $item['anchor']).'/'.rawurlencode($item['file_name']);

			$output = '<div id="swf_'.$item['id'].'" class="no_print">Flash plugin or Javascript are turned off. Activate both and reload to view the object</div>'."\n"
				.JS_PREFIX
				.'var params = {};'."\n"
				.'params.base = "'.dirname($url).'/";'."\n"
				.'params.quality = "high";'."\n"
				.'params.wmode = "transparent";'."\n"
				.'params.allowfullscreen = "true";'."\n"
				.'params.allowscriptaccess = "always";'."\n"
				.'params.flashvars = "'.$flashvars.'";'."\n"
				.'swfobject.embedSWF("'.$url.'", "swf_'.$item['id'].'", "'.$width.'", "'.$height.'", "6", "'.$context['url_to_home'].$context['url_to_root'].'included/browser/expressinstall.swf", false, params);'."\n"
				.JS_SUFFIX."\n";
			return $output;

		// link to file page
		default:

			// link label
			$text = Skin::strip( $item['title']?$item['title']:str_replace('_', ' ', $item['file_name']) );

			// make a link to the target page
			$url = Files::get_permalink($item);

			// return a complete anchor
			$output =& Skin::build_link($url, $text);
			return $output;

		}

	}

	/**
	 * escape code sequences
	 *
	 * @param string the text
	 * @return string the rendered text
	**/
	function &render_escaped($text) {

		// replace strings --initialize only once
		static $from, $to;
		if(!isset($from)) {

			// chars or strings to be escaped
			$tags = array(
				'##' => '&#35;&#35;',
				'*' => '&#42;',
				'+' => '&#43;',
				'-' => '&#45;',
				'/' => '&#47;',
				':' => '&#58;',
				'=' => '&#61;',
				'[' => '&#91;',
				']' => '&#93;',
				'_' => '&#95;',
				'<' => '&#139;' // escape HTML as well
			);

			// initialize only once
			$from = array();
			$to = array();
			foreach($tags as $needle => $replace) {
				$from[] = $needle;
				$to[] = $replace;
			}
		}

		// do the job
		$text = str_replace($from, $to, $text);

		$output = '<code>'.nl2br($text).'</code>';
		return $output;
	}

	/**
	 * render an interactive Freemind map
	 *
	 * The id can be:
	 * - 'sections' - the entire content tree
	 * - 'section:123' - some branch of the content tree
	 * - '123' - the file with the provided id, if it is a Freemind map
	 * - 'http://link/to/a/map.mm' - has to reference this server
	 *
	 * The id can also include width and height of the target canvas, as in
	 * following examples:
	 * - '100%, 250px' - actual id is assumed to be 'sections'
	 * - 'section:4059, 100%, 250px'
	 *
	 * The Flash viewer is available at http://evamoraga.net/efectokiwano/mm/index.mm
	 *
	 * @link http://evamoraga.net/efectokiwano/mm/index.mm
	 *
	 * @param string id of the target map
	 * @return string the rendered string
	**/
	function &render_freemind($id) {
		global $context;

		// process parameters
		$attributes = preg_split("/\s*,\s*/", $id, 3);
		switch(count($attributes)) {
		case 3: // id, width, height
			$id = $attributes[0];
			$width = $attributes[1];
			$height = $attributes[2];
			break;
		case 2: // width, height
			$id = 'sections';
			$width = $attributes[0];
			$height = $attributes[1];
			break;
		case 1: // id
			$id = $attributes[0];
			$width = isset($context['skins_freemind_canvas_width']) ? $context['skins_freemind_canvas_width'] : '100%';
			$height = isset($context['skins_freemind_canvas_height']) ? $context['skins_freemind_canvas_height'] : '500px';
			break;
		}

		// additional commands
		$menu = array();

		// web reference to site full content
		if($id == 'sections') {
			$target_href = $context['url_to_home'].$context['url_to_root'].Sections::get_url('all', 'freemind', utf8::to_ascii($context['site_name'].'.mm'));
			$menu = array_merge($menu, array(Sections::get_url('all', 'view_as_freemind', utf8::to_ascii($context['site_name'].'.mm')) => i18n::s('Full-size')));

		// content of one section
		} elseif(($position = strpos($id, 'section:')) !== FALSE) {

			if(!$item =& Sections::get(substr($id, $position + strlen('section:')))) {
				$text = '[freemind='.$id.']';
				return $text;
			}

			$target_href = $context['url_to_home'].$context['url_to_root'].Sections::get_url($item['id'], 'freemind', utf8::to_ascii($context['site_name'].' - '.strip_tags(Codes::beautify(trim($item['title']))).'.mm'));

			$menu = array_merge($menu, array(Sections::get_url($item['id'], 'view_as_freemind', utf8::to_ascii($context['site_name'].' - '.strip_tags(Codes::beautify(trim($item['title']))).'.mm')) => i18n::s('Full-size')));

		// direct reference to the target file
		} elseif(strpos($id, $context['url_to_home']) === 0) {
			$target_href = $id;

		// one file, as a freemind map
		} elseif(($item =& Files::get($id)) && isset($item['id'])) {

			// if we have an external reference, use it
			if(isset($item['file_href']) && $item['file_href']) {
				$target_href = $item['file_href'];

			// else redirect to ourself
			} else {

				// ensure a valid file name
				$file_name = utf8::to_ascii($item['file_name']);

				// where the file is
				$path = 'files/'.$context['virtual_path'].str_replace(':', '/', $item['anchor']).'/'.rawurlencode($item['file_name']);

				// map the file on the regular web space
				$url_prefix = $context['url_to_home'].$context['url_to_root'];

				// redirect to the actual file
				$target_href = $url_prefix.$path;
			}

		// no way to render this id
		} else {
			$text = '[freemind='.$id.']';
			return $text;
		}

		// allow several viewers to co-exist in the same page
		static $freemind_viewer_index;
		if(!isset($freemind_viewer_index))
			$freemind_viewer_index = 1;
		else
			$freemind_viewer_index++;

		// load flash player
		$url = $context['url_to_home'].$context['url_to_root'].'included/browser/visorFreemind.swf';

		// variables
		$flashvars = 'initLoadFile='.$target_href.'&openUrl=_self';

		$text = '<div id="freemind_viewer_'.$freemind_viewer_index.'">Flash plugin or Javascript are turned off. Activate both and reload to view the object</div>'."\n"
			.JS_PREFIX
			.'var params = {};'."\n"
			.'params.base = "'.dirname($url).'/";'."\n"
			.'params.quality = "high";'."\n"
			.'params.wmode = "transparent";'."\n"
			.'params.menu = "false";'."\n"
			.'params.flashvars = "'.$flashvars.'";'."\n"
			.'swfobject.embedSWF("'.$url.'", "freemind_viewer_'.$freemind_viewer_index.'", "'.$width.'", "'.$height.'", "6", "'.$context['url_to_home'].$context['url_to_root'].'included/browser/expressinstall.swf", false, params);'."\n"
			.JS_SUFFIX."\n";

		// offer to download a copy of the map
		$menu = array_merge($menu, array($target_href => i18n::s('Browse this map with Freemind')));

		// display menu commands below the viewer
		if(count($menu))
			$text .= Skin::build_list($menu, 'menu_bar');

		// job done
		return $text;

	}

	/**
	 * render a graphviz
	 *
	 * @param string the text
	 * @param string the variant
	 * @return string the rendered text
	**/
	function &render_graphviz($text, $variant='digraph') {
		global $context;

		// sanity check
		if(!$text)
			$text = 'Hello->World!';

		// remove tags put by WYSIWYG editors
		$text = strip_tags(str_replace(array('&gt;', '&lt;', '&amp;', '&quot;', '\"'), array('>', '<', '&', '"', '"'), str_replace(array('<br />', '</p>'), "\n", $text)));

		// build the .dot content
		switch($variant) {
		case 'digraph':
		default:
			$text = 'digraph G { '.$text.' }'."\n";
			break;
		}

		// id for this object
		$hash = md5($text);

		// path to cached files
		$path = $context['path_to_root'].'temporary/graphviz.';

		// we cache content
		if($content = Safe::file_get_contents($path.$hash.'.html'))
			return $content;

		// build a .dot file
		if(!Safe::file_put_contents($path.$hash.'.dot', $text)) {
			$content = '[error writing .dot file]';
			return $content;
		}

		// process the .dot file
		if(isset($context['dot.command']))
			$command = $context['dot.command'];
		else
			$command = 'dot';
//		$font = '"/System/Library/Fonts/Times.dfont"';
//		$command = '/sw/bin/dot -v -Nfontname='.$font
		$command .= ' -Tcmapx -o "'.$path.$hash.'.map"'
			.' -Tpng -o "'.$path.$hash.'.png"'
			.' "'.$path.$hash.'.dot"';

		if(Safe::shell_exec($command) == NULL) {
			$content = '[error while using graphviz]';
			return $content;
		}

		// produce the HTML
		$content = '<img src="'.$context['url_to_root'].'temporary/graphviz.'.$hash.'.png" usemap="#mainmap" />';
		$content .= Safe::file_get_contents($path.$hash.'.map');

		// put in cache
		Safe::file_put_contents($path.$hash.'.html', $content);

		// done
		return $content;
	}


	/**
	 * render or not some text
	 *
	 * If variant = 'anonymous' and surfer is not logged, then display the block.
	 * If the surfer is an associate, then display the text.
	 * Else if the surfer is an authenticated member and variant = 'restricted', then display the text
	 * Else return an empty string
	 *
	 * @param string the text
	 * @param either 'anonymous', or 'restricted' or 'hidden'
	 * @return string the rendered text
	**/
	function &render_hidden($text, $variant) {

		// this block should only be visible from non-logged surfers
		if($variant == 'anonymous') {
			if(Surfer::is_logged())
				$text = '';
			return $text;
		}

		// associates may see everything else
		if(Surfer::is_associate())
			return $text;

		// this block is restricted to members
		if(Surfer::is_member() && ($variant == 'restricted'))
			return $text;

		// tough luck
		$text = '';
		return $text;
	}

	/**
	 * render an iframe
	 *
	 * @param string URL to be embedded
	 * @param string iframe parameters
	 * @return string the rendered text
	**/
	function &render_iframe($url, $variant) {
		global $context;

		// split parameters
		$attributes = preg_split("/\s*,\s*/", $variant, 2);

		// set a default size
		if(!isset($attributes[0]))
			$attributes[0] = 320;
		if(!isset($attributes[1]))
			$attributes[1] = 240;

		$text = '<iframe src="'.$url.'" style="width: '.$attributes[0].'px; height: '.$attributes[1].'px" scrolling="no" marginwidth="0" marginheight="0" frameborder="0" vspace="0" hspace="0">'."\n"
			.i18n::s('Your browser does not accept iframes')
			.'</iframe>';

		return $text;

	}

	/**
	 * render a list
	 *
	 * @param string the list content
	 * @param string the variant, if any
	 * @return string the rendered text
	**/
	function &render_list($content, $variant='') {
		global $context;

		if(!$content = trim($content)) {
			$output = NULL;
			return $output;
		}

		// preserve existing list, if any --coming from implied beautification
		if(preg_match('#^<ul>#', $content) && preg_match('#</ul>$#', $content))
			$items = preg_replace(array('#^<ul>#', '#</ul>$#'), '', $content);

		// split items
		else {
			$content = preg_replace(array("/<br \/>\n-/s", "/\n-/s", "/^-/", '/\[\*\]/'), '[*]', $content);
			$items = '<li>'.join('</li><li>', preg_split("/\[\*\]/s", $content, -1, PREG_SPLIT_NO_EMPTY)).'</li>';
		}

		// an ordinary bulleted list
		if(!$variant) {
			$output = '<ul>'.$items.'</ul>';
			return $output;

		// style a bulleted list, but ensure it's not numbered '1 incremental'
		} elseif($variant && (strlen($variant) > 1) && ($variant[1] != ' ')) {
			$output = '<ul class="'.$variant.'">'.$items.'</ul>';
			return $output;
		}

		// type has been deprecated, use styles
		$style = '';
		switch($variant) {
		case 'a':
			$style = 'style="list-style-type: lower-alpha"';
			break;

		case 'A':
			$style = 'style="list-style-type: upper-alpha"';
			break;

		case 'i':
			$style = 'style="list-style-type: lower-roman"';
			break;

		case 'I':
			$style = 'style="list-style-type: upper-roman"';
			break;

		default:
			$style = 'class="'.encode_field($variant).'"';
			break;

		}

		// a numbered list with style
		$output = '<ol '.$style.'>'.$items.'</ol>';
		return $output;
	}

	/**
	 * render a location
	 *
	 * @param string the id, with possible options or variant
	 * @return string the rendered text
	**/
	function &render_location($id) {
		global $context;

		// the required library
		include_once $context['path_to_root'].'locations/locations.php';

		// check all args
		$attributes = preg_split("/\s*,\s*/", $id, 3);

		// [location=latitude, longitude, label]
		if(count($attributes) === 3) {
			$item = array();
			$item['latitude'] = $attributes[0];
			$item['longitude'] = $attributes[1];
			$item['description'] = $attributes[2];

		// [location=id, label] or [location=id]
		} else {
			$id = $attributes[0];

			// a record is mandatory
			if(!$item =& Locations::get($id)) {
				if(Surfer::is_member()) {
					$output = '&#91;location='.$id.']';
					return $output;
				} else {
					$output = '';
					return $output;
				}
			}

			// build a small dynamic image if we cannot use Google maps
			if(!isset($context['google_api_key']) || !$context['google_api_key']) {
				$output = BR.'<img src="'.$context['url_to_root'].'locations/map_on_earth.php?id='.$item['id'].'" width="310" height="155" alt="'.$item['geo_position'].'" />'.BR;
				return $output;
			}

			// use provided text, if any
			if(isset($attributes[1]))
				$item['description'] = $attributes[1].BR.$item['description'];

		}

		// map on Google
		$output =& Locations::map_on_google(array($item));
		return $output;

	}

	/**
	 * render several locations
	 *
	 * @param string 'all' or 'users'
	 * @return string the rendered text
	**/
	function &render_locations($id='all') {
		global $context;

		// the required library
		include_once $context['path_to_root'].'locations/locations.php';

		// get markers
		$items = array();
		switch($id) {
		case 'all':
			$items = Locations::list_by_date(0, 100, 'raw');
			break;

		case 'users':
			$items = Locations::list_users_by_date(0, 100, 'raw');
			break;

		default:
			if(Surfer::is_member()) {
				$output = '&#91;locations='.$id.']';
				return $output;
			} else {
				$output = '';
				return $output;
			}
		}

		// integrate with google maps
		$output =& Locations::map_on_google($items);
		return $output;

	}

	/**
	 * render some animated news
	 *
	 * We have replaced the old fat object by a lean, clean, and valid XHTML solution.
	 * However, as explained by Jeffrey Zeldmann in his book "designing with web standards",
	 * it may happen that this way of doing don't display correctly sometimes.
	 *
	 * @param string the variant - default is 'flash'
	 * @return string the rendered text
	**/
	function &render_news($variant) {
		global $context;

		switch($variant) {
		case 'flash':

			// sanity check
			if(!isset($context['root_flash_at_home']) || ($context['root_flash_at_home'] != 'Y'))
				$text = '';

			else {
				$url = $context['url_to_home'].$context['url_to_root'].'feeds/flash/slashdot.php';
				$flashvars = '';
				$text = '<div id="local_news" class="no_print">Flash plugin or Javascript are turned off. Activate both and reload to view the object</div>'."\n"
					.JS_PREFIX
					.'var params = {};'."\n"
					.'params.base = "'.dirname($url).'/";'."\n"
					.'params.quality = "high";'."\n"
					.'params.wmode = "transparent";'."\n"
					.'params.menu = "false";'."\n"
					.'params.flashvars = "'.$flashvars.'";'."\n"
					.'swfobject.embedSWF("'.$url.'", "local_news", "80%", "50", "6", "'.$context['url_to_home'].$context['url_to_root'].'included/browser/expressinstall.swf", false, params);'."\n"
					.JS_SUFFIX;
			}

			return $text;

		case 'dummy':
			$text = 'hello world';
			return $text;

		default:
			$text = '??'.$variant.'??';
			return $text;
		}
	}

	/**
	 * integrate content of a newsfeed
	 *
	 * @param string address of the newsfeed to get
	 * @return string the rendered text
	**/
	function &render_newsfeed($url, $variant='ajax') {
		global $context;

		// we allow multiple calls
		static $count;
		if(!isset($count))
			$count = 1;
		else
			$count++;

		switch($variant) {

		case 'ajax': // asynchronous loading
		default:

			$text = '<div id="newsfeed_'.$count.'" class="no_print"></div>'."\n"
			.JS_PREFIX
			.'Event.observe(window, "load", function() { Yacs.spin("newsfeed_'.$count.'"); Yacs.call( { method: \'feed.proxy\', params: { url: \''.$url.'\' } }, function(s) { if(s.text) { $("newsfeed_'.$count.'").update(s.text.toString()); } else { $("newsfeed_'.$count.'").update(""); } } ) } );'."\n"
			.JS_SUFFIX;

			return $text;

		case 'embed': // integrate newsfeed into the page

			include_once $context['path_to_root'].'feeds/proxy_hook.php';
			$parameters = array('url' => $url);
			if($output = Proxy_hook::serve($parameters))
				$text = $output['text'];

			return $text;

		}
	}

	/**
	 * render a link to an object
	 *
	 * Following types are supported:
	 * - action - link to an action page
	 * - article - link to an article page
	 * - category - link to a category page
	 * - comment - link to a comment page
	 * - decision - link to a decision page
	 * - download - link to a download page
	 * - file - link to a file page
	 * - flash - display a file as a native flash object, or play a flash video
	 * - sound - launch dewplayer
	 * - go
	 * - image - display an in-line image
	 * - next - link to an article page
	 * - previous - link to an article page
	 * - section - link to a section page
	 * - server - link to a server page
	 * - user - link to a user page
	 *
	 * @param string the type
	 * @param string the id, with possible options or variant
	 * @return string the rendered text
	**/
	function &render_object($type, $id) {
		global $context;

		// depending on type
		switch($type) {

		// link to an action
		case 'action':
			include_once $context['path_to_root'].'actions/actions.php';

			// maybe an alternate title has been provided
			$attributes = preg_split("/\s*,\s*/", $id, 2);
			$id = $attributes[0];

			// load the record from the database
			if(!$item =& Actions::get($id))
				$output = '[action='.$id.']';

			else {

				// ensure we have a label for this link
				if(isset($attributes[1]))
					$text = $attributes[1];
				else
					$text =& Skin::strip($item['title']);

				// make a link to the target page
				$url = $context['url_to_home'].$context['url_to_root'].Actions::get_url($item['id']);

				// return a complete anchor
				$output =& Skin::build_link($url, $text, 'basic');
			}

			return $output;

		// link to an article
		case 'article':

			// maybe an alternate title has been provided
			$attributes = preg_split("/\s*,\s*/", $id, 2);
			$id = $attributes[0];

			// load the record from the database
			if(!$item =& Articles::get($id))
				$output = '[article='.$id.']';

			else {

				// ensure we have a label for this link
				if(isset($attributes[1])) {
					$text = $attributes[1];
					$type = 'basic';
				} else
					$text = Skin::strip($item['title']);

				// make a link to the target page
				$url =& Articles::get_permalink($item);

				// return a complete anchor
				$output =& Skin::build_link($url, $text, $type);
			}

			return $output;

		// insert article description
		case 'article.description':

			// maybe an alternate title has been provided
			$attributes = preg_split("/\s*,\s*/", $id, 2);
			$id = $attributes[0];

			// load the record from the database
			if(!$item =& Articles::get($id))
				$output = '[article.description='.$id.']';

			else {

				// ensure we have a label for this link
				if(isset($attributes[1])) {
					$text = $attributes[1];
					$type = 'basic';
				} else
					$text = Skin::strip($item['title']);

				// make a link to the target page
				$url =& Articles::get_permalink($item);

				// return a complete anchor
				$output =& Skin::build_link($url, $text, 'article');

				// the introduction text, if any
				$output .= BR.Codes::beautify($item['introduction']);

				// load overlay, if any
				if(isset($item['overlay']) && $item['overlay']) {
					include_once '../overlays/overlay.php';
					$overlay = Overlay::load($item);

					// get text related to the overlay, if any
					if(is_object($overlay))
						$output .= $overlay->get_text('view', $item);

				}

				// the description, which is the actual page body
				$output .= '<div>'.Codes::beautify($item['description']).'</div>';

			}

			return $output;

		// link to a category
		case 'category':

			// maybe an alternate title has been provided
			$attributes = preg_split("/\s*,\s*/", $id, 2);
			$id = $attributes[0];

			// load the record from the database
			if(!$item =& Categories::get($id))
				$output = '[category='.$id.']';

			else {

				// ensure we have a label for this link
				if(isset($attributes[1])) {
					$text = $attributes[1];
					$type = 'basic';
				} else
					$text = Skin::strip($item['title']);

				// make a link to the target page
				$url =& Categories::get_permalink($item);

				// return a complete anchor
				$output =& Skin::build_link($url, $text, $type);
			}

			return $output;

		// insert category description
		case 'category.description':

			// maybe an alternate title has been provided
			$attributes = preg_split("/\s*,\s*/", $id, 2);
			$id = $attributes[0];

			// load the record from the database
			if(!$item =& Categories::get($id))
				$output = '[category.description='.$id.']';

			else {

				// ensure we have a label for this link
				if(isset($attributes[1])) {
					$text = $attributes[1];
					$type = 'basic';
				} else
					$text = Skin::strip($item['title']);

				// make a link to the target page
				$url =& Categories::get_permalink($item);

				// return a complete anchor
				$output =& Skin::build_link($url, $text, 'category');

				// the introduction text, if any
				$output .= BR.Codes::beautify($item['introduction']);

				// load overlay, if any
				if(isset($item['overlay']) && $item['overlay']) {
					include_once '../overlays/overlay.php';
					$overlay = Overlay::load($item);

					// get text related to the overlay, if any
					if(is_object($overlay))
						$output .= $overlay->get_text('view', $item);

				}

				// the description, which is the actual page body
				$output .= '<div>'.Codes::beautify($item['description']).'</div>';

			}

			return $output;

		// link to a comment
		case 'comment':
			include_once $context['path_to_root'].'comments/comments.php';

			// maybe an alternate title has been provided
			$attributes = preg_split("/\s*,\s*/", $id, 2);
			$id = $attributes[0];

			// load the record from the database
			if(!$item =& Comments::get($id))
				$output = '[comment='.$id.']';

			else {

				// ensure we have a label for this link
				if(isset($attributes[1]))
					$text = $attributes[1];
				else
					$text = i18n::s('View this comment');

				// make a link to the target page
				$url = $context['url_to_home'].$context['url_to_root'].Comments::get_url($item['id']);

				// return a complete anchor
				$output =& Skin::build_link($url, $text, 'basic');
			}

			return $output;

		// link to a decision
		case 'decision':
			include_once $context['path_to_root'].'decisions/decisions.php';

			// maybe an alternate title has been provided
			$attributes = preg_split("/\s*,\s*/", $id, 2);
			$id = $attributes[0];

			// load the record from the database
			if(!$item =& Decisions::get($id))
				$output = '[decision='.$id.']';

			else {

				// ensure we have a label for this link
				if(isset($attributes[1]))
					$text = $attributes[1];
				else
					$text = i18n::s('View this decision');

				// make a link to the target page
				$url = $context['url_to_home'].$context['url_to_root'].Decisions::get_url($item['id']);

				// return a complete anchor
				$output =& Skin::build_link($url, $text, 'basic');

			}
			return $output;

		// link to a download
		case 'download':

			// maybe an alternate title has been provided
			$attributes = preg_split("/\s*,\s*/", $id, 2);
			$id = $attributes[0];

			// load the record from the database
			if(!$item =& Files::get($id))
				$output = '[download='.$id.']';

			else {

				// ensure we have a label for this link
				if(isset($attributes[1]))
					$text = $attributes[1];
				else
					$text = Skin::strip( $item['title']?$item['title']:str_replace('_', ' ', $item['file_name']) );

				// always download the file
				$url = $context['url_to_home'].$context['url_to_root'].Files::get_url($item['id'], 'fetch', $item['file_name']);

				// return a complete anchor
				$output =& Skin::build_link($url, $text, 'file');
			}

			return $output;

		// link to a file
		case 'file':

			// maybe an alternate title has been provided
			$attributes = preg_split("/\s*,\s*/", $id, 2);
			$id = $attributes[0];

			// load the record from the database
			if(!$item =& Files::get($id))
				$output = '[file='.$id.']';

			else {

				// maybe we want to illustrate this file
				$output = Files::interact($item);

				// ensure we have a label for this link
				if(isset($attributes[1]))
					$text = $attributes[1];
				else
					$text = Skin::strip( $item['title']?$item['title']:str_replace('_', ' ', $item['file_name']) );

				// make a link to the target page
				$url = Files::get_permalink($item);

				// return a complete anchor
				$output .= Skin::build_link($url, $text, 'basic');
			}
			return $output;

		// link to a form
		case 'form':
			include_once $context['path_to_root'].'forms/forms.php';

			// maybe an alternate title has been provided
			$attributes = preg_split("/\s*,\s*/", $id, 2);
			$id = $attributes[0];

			// load the record from the database
			if(!$item =& Forms::get($id))
				$output = '[form='.$id.']';

			else {

				// ensure we have a label for this link
				if(isset($attributes[1])) {
					$text = $attributes[1];
					$type = 'basic';
				} else
					$text = Skin::strip($item['title']);

				// make a link to the target page
				$url = $context['url_to_home'].$context['url_to_root'].Forms::get_url($item['id']);

				// return a complete anchor
				$output =& Skin::build_link($url, $text, $type);
			}

			return $output;

		// invoke the selector
		case 'go':

			// extract the label, if any
			$attributes = preg_split("/\s*,\s*/", $id, 2);
			$name = $attributes[0];

			// ensure we have a label for this link
			if(isset($attributes[1]))
				$text = $attributes[1];
			else
				$text = $name;

			// return a complete anchor
			$output = Skin::build_link($context['url_to_home'].$context['url_to_root'].normalize_shortcut($name), $text, 'basic');
			return $output;

		// embed an image
		case 'image':
			include_once $context['path_to_root'].'images/images.php';

			// get the variant, if any
			$attributes = preg_split("/\s*,\s*/", $id, 2);
			$id = $attributes[0];
			if(isset($attributes[1]))
				$variant = $attributes[1];
			else
				$variant = 'inline';

			// get the image record
			if(!$image =& Images::get($id)) {
				$output = '[image='.$id.']';
				return $output;
			}

			// a title for the image --do not force a title
			if(isset($image['title']))
				$title = $image['title'];
			else
				$title = '';

			// provide thumbnail if not defined, or forced, or for large images
			if(!$image['use_thumbnail']
				|| ($image['use_thumbnail'] == 'A')
				|| (($image['use_thumbnail'] == 'Y') && ($image['image_size'] > $context['thumbnail_threshold'])) ) {

				// not inline anymore, but thumbnail --preserve other variants
				if($variant == 'inline')
					$variant = 'thumbnail';

				// where to fetch the image file
				$href = Images::get_thumbnail_href($image);

				// to drive to plain image
				$link = Images::get_icon_href($image);

			// add an url, if any
			} elseif($image['link_url']) {

				// flag large images
				if($image['image_size'] > $context['thumbnail_threshold'])
					$variant = rtrim('large '.$variant);

				// where to fetch the image file
				$href = Images::get_icon_href($image);

				// transform local references, if any
				include_once $context['path_to_root'].'/links/links.php';
				$attributes = Links::transform_reference($image['link_url']);
				if($attributes[0])
					$link = $context['url_to_root'].$attributes[0];

				// direct use of this link
				else
					$link = $image['link_url'];

			// get the <img ... /> element
			} else {

				// do not append poor titles to inline images
				if($variant == 'inline')
					$title = '';

				// flag large images
				if($image['image_size'] > $context['thumbnail_threshold'])
					$variant = rtrim('large '.$variant);

				// where to fetch the image file
				$href = Images::get_icon_href($image);

				// no link
				$link = '';

			}

			// use the skin
			if(Images::allow_modification($image['anchor'],$id))
			   // build editable image
			   $output =& Skin::build_image($variant, $href, $title, $link, $id);
			else 
			   $output =& Skin::build_image($variant, $href, $title, $link);
			return $output;

		// embed a stack of images
		case 'images':
			include_once $context['path_to_root'].'images/images.php';

			// get the list of ids
			$ids = preg_split("/\s*,\s*/", $id);
			if(!count($ids)) {
				$output =  '[images=id1, id2, ...]';
				return $output;
			}

			// build the list of images
			$items = array();
			foreach($ids as $id) {

				// get the image record
				if($image =& Images::get($id)) {

					// a title for the image --do not force a title
					if(isset($image['title']))
						$title = $image['title'];
					else
						$title = '';

					// provide thumbnail if not defined, or forced, or for large images
					$variant = 'inline';
					if(!$image['use_thumbnail']
						|| ($image['use_thumbnail'] == 'A')
						|| (($image['use_thumbnail'] == 'Y') && ($image['image_size'] > $context['thumbnail_threshold'])) ) {

						// not inline anymore, but thumbnail
						$variant = 'thumbnail';

						// where to fetch the image file
						$href = Images::get_thumbnail_href($image);

						// to drive to plain image
						$link = $context['url_to_root'].Images::get_url($id);

					// add an url, if any
					} elseif($image['link_url']) {

						// flag large images
						if($image['image_size'] > $context['thumbnail_threshold'])
							$variant = rtrim('large '.$variant);

						// where to fetch the image file
						$href = Images::get_icon_href($image);

						// transform local references, if any
						include_once $context['path_to_root'].'/links/links.php';
						$attributes = Links::transform_reference($image['link_url']);
						if($attributes[0])
							$link = $context['url_to_root'].$attributes[0];

						// direct use of this link
						else
							$link = $image['link_url'];

					// get the <img ... /> element
					} else {

						// flag large images
						if($image['image_size'] > $context['thumbnail_threshold'])
							$variant = rtrim('large '.$variant);

						// where to fetch the image file
						$href = Images::get_icon_href($image);

						// no link
						$link = '';

					}

					// use the skin
					$label =& Skin::build_image($variant, $href, $title, $link);

					// add item to the stack
					$items[]  = $label;

				}

			}

			// format the list
			$output = '';
			if(count($items)) {

				// stack items
				$output = Skin::finalize_list($items, 'stack');

				// rotate items
				$output = Skin::rotate($output);
			}

			// done
			return $output;

		// link to the next article
		case 'next':

			// maybe an alternate title has been provided
			$attributes = preg_split("/\s*,\s*/", $id, 2);
			$id = $attributes[0];

			// load the record from the database
			if(!$item =& Articles::get($id))
				$output = '[next='.$id.']';

			else {

				// ensure we have a label for this link
				if(isset($attributes[1]))
					$text = $attributes[1];
				else
					$text = Skin::strip($item['title']);

				// make a link to the target page
				$url = Articles::get_permalink($item);

				// return a complete anchor
				$output =& Skin::build_link($url, $text, 'next');
			}

			return $output;

		// link to the previous article
		case 'previous':

			// maybe an alternate title has been provided
			$attributes = preg_split("/\s*,\s*/", $id, 2);
			$id = $attributes[0];

			// load the record from the database
			if(!$item =& Articles::get($id))
				$output = '[previous='.$id.']';

			else {

				// ensure we have a label for this link
				if(isset($attributes[1]))
					$text = $attributes[1];
				else
					$text = Skin::strip($item['title']);

				// make a link to the target page
				$url = Articles::get_permalink($item);

				// return a complete anchor
				$output =& Skin::build_link($url, $text, 'previous');
			}

			return $output;

		// link to a section
		case 'section':

			// maybe an alternate title has been provided
			$attributes = preg_split("/\s*,\s*/", $id, 2);
			$id = $attributes[0];

			// load the record from the database
			if(!$item =& Sections::get($id))
				$output = '[section='.$id.']';

			else {

				// ensure we have a label for this link
				if(isset($attributes[1])) {
					$text = $attributes[1];
					$type = 'basic';
				} else
					$text = Skin::strip($item['title']);

				// make a link to the target page
				$url =& Sections::get_permalink($item);

				// return a complete anchor
				$output =& Skin::build_link($url, $text, $type);
			}

			return $output;

		// link to a server
		case 'server':
			include_once $context['path_to_root'].'servers/servers.php';

			// maybe an alternate title has been provided
			$attributes = preg_split("/\s*,\s*/", $id, 2);
			$id = $attributes[0];

			// load the record from the database
			if(!$item =& Servers::get($id))
				$output = '[server='.$id.']';

			else {

				// ensure we have a label for this link
				if(isset($attributes[1])) {
					$text = $attributes[1];
					$type = 'basic';
				} else
					$text = Skin::strip($item['title']);

				// make a link to the target page
				$url = $context['url_to_home'].$context['url_to_root'].Servers::get_url($id);

				// return a complete anchor
				$output =& Skin::build_link($url, $text, $type);
			}

			return $output;

		// render a sound object
		case 'sound':

			// maybe an alternate title has been provided
			$attributes = preg_split("/\s*,\s*/", $id, 2);
			$id = $attributes[0];
			$flashvars = '';
			if(isset($attributes[1]))
				$flashvars = $attributes[1];

			// get the file
			if(!$item =& Files::get($id)) {
				$output = '[sound='.$id.']';
				return $output;
			}

			// where to get the file
			if(isset($item['file_href']) && $item['file_href'])
				$url = $item['file_href'];
			else
				$url = $context['url_to_home'].$context['url_to_root'].'files/'.str_replace(':', '/', $item['anchor']).'/'.rawurlencode($item['file_name']);

			// several ways to play flash
			switch(strtolower(substr(strrchr($url, '.'), 1))) {

			// stream a sound file
			case 'mp3':

				// a flash player to stream a sound
				$dewplayer_url = $context['url_to_root'].'included/browser/dewplayer.swf';
				if($flashvars)
					$flashvars = 'son='.$url.'&'.$flashvars;
				else
					$flashvars = 'son='.$url;

				$output = '<div id="sound_'.$item['id'].'" class="no_print">Flash plugin or Javascript are turned off. Activate both and reload to view the object</div>'."\n"
					.JS_PREFIX
					.'var params = {};'."\n"
					.'params.base = "'.dirname($url).'/";'."\n"
					.'params.quality = "high";'."\n"
					.'params.wmode = "transparent";'."\n"
					.'params.menu = "false";'."\n"
					.'params.flashvars = "'.$flashvars.'";'."\n"
					.'swfobject.embedSWF("'.$dewplayer_url.'", "sound_'.$item['id'].'", "200", "20", "6", "'.$context['url_to_home'].$context['url_to_root'].'included/browser/expressinstall.swf", false, params);'."\n"
					.JS_SUFFIX."\n";
				return $output;

			// link to file page
			default:

				// link label
				$text = Skin::strip( $item['title']?$item['title']:str_replace('_', ' ', $item['file_name']) );

				// make a link to the target page
				$url = Files::get_permalink($item);

				// return a complete anchor
				$output =& Skin::build_link($url, $text, 'basic');
				return $output;

			}

		// link to a user
		case 'user':

			// maybe an alternate title has been provided
			$attributes = preg_split("/\s*,\s*/", $id, 2);
			$id = $attributes[0];

			// load the record from the database
			if(!$item =& Users::get($id))
				$output = '[user='.$id.']';

			else {

				// ensure we have a label for this link
				if(isset($attributes[1])) {
					$text = $attributes[1];
					$type = 'basic';
				} elseif(isset($item['full_name']) && $item['full_name'])
					$text = ucfirst($item['full_name']);
				else
					$text = ucfirst($item['nick_name']);

				// make a link to the target page
				$url = Users::get_permalink($item);

				// return a complete anchor
				$output =& Skin::build_link($url, $text, $type);
			}

			return $output;

		// invalid type
		default:
			$output = '['.$type.']';
			return $output;

		}

	}

	/**
	 * render a block of code
	 *
	 * @param string the text
	 * @return string the rendered text
	**/
	function &render_pre($text, $variant='snippet') {

		// change new lines
		$text = trim(str_replace("\r", '', str_replace(array("<br>\n", "<br/>\n", "<br />\n", '<br>', '<br/>', '<br />'), "\n", $text)));

		// caught from tinymce
		if(preg_match('/<p>(.*)<\/p>$/s', $text, $matches)) {
			$text = $matches[1];
			$text = str_replace(array('&amp;', '<p>', '</p>'), array('&', '', "\n"), $text);
		}

		// match some php code
		$explicit = FALSE;
		if(preg_match('/<\?php\s/', $text))
			$variant = 'php';
		elseif(($variant == 'php') && !preg_match('/<\?'.'php.+'.'\?'.'>/', $text)) {
			$text = '<?'.'php'."\n".$text."\n".'?'.'>';
			$explicit = TRUE;
		}

		// highlight php code, if any
		if($variant == 'php') {

			// fix some chars set by wysiwig editors
			$text = str_replace(array('&lt;', '&gt;', '&nbsp;', '&quot;'), array('<', '>', ' ', '"'), $text);

			// wrap long lines if necessary
// 			$lines = explode("\n", $text);
// 			$text = '';
// 			foreach($lines as $line)
// 				$text .= wordwrap($line, 100, " \n", 0)."\n";

			// handle newlines and indentations properly
			$text = str_replace(array("\n<span", "\n</code", "\n</pre", "\n</span"), array('<span', '</code', '</pre', '</span'), Safe::highlight_string($text));

			// remove explicit php prefix and suffix -- dependant of highlight_string() evolution
			if($explicit)
				$text = preg_replace(array('/&lt;\?php<br\s*\/>/', '/\?&gt;/'), '', $text);

		// or prevent html rendering
		} else
			$text = str_replace(array('<', "\n"), array('&lt;', '<br/>'), $text);

		// prevent additional transformations
		$search = array(	'[',		']',		':',		'//',			'##',			'**',			'++',			'--',			'__');
		$replace = array(	'&#91;',	'&#93;',	'&#58;',	'&#47;&#47;',	'&#35;&#35;',	'&#42;&#42;',	'&#43;&#43;',	'&#45;&#45;',	'&#95;&#95;');
		$output = '<pre>'.str_replace($search, $replace, $text).'</pre>';

		return $output;

	}

	/**
	 * render a compact list of recent publications
	 *
	 * The provided anchor can reference:
	 * - a section 'section:123'
	 * - a category 'category:456'
	 * - a user 'user:789'
	 * - 'self'
	 * - nothing
	 *
	 * @param string the anchor (e.g. 'section:123')
	 * @param string layout to use
	 * @return string the rendered text
	**/
	function &render_published($anchor='', $layout='compact') {
		global $context;

		// we return some text;
		$text = '';

		// number of items to display
		$count = COMPACT_LIST_SIZE;
		if($position = strrpos($anchor, ',')) {
			$count = (integer)trim(substr($anchor, $position+1));
			if(!$count)
				$count = COMPACT_LIST_SIZE;

			$anchor = trim(substr($anchor, 0, $position));
		}

		// scope is limited to current surfer
		if(($anchor == 'self') && Surfer::get_id()) {
			$anchor = 'user:'.Surfer::get_id();

			// refresh on every page load
			Cache::poison();

		}

		// scope is limited to one section
		if(strpos($anchor, 'section:') === 0) {

			// look at this level
			$anchors = array($anchor);

			// first level of depth
			$topics =& Sections::get_children_of_anchor($anchor, 'main');
			$anchors = array_merge($anchors, $topics);

			// second level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($topics, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// third level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($topics, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// fourth level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($topics, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// fifth level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($topics, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// query the database and layout that stuff
			$text =& Articles::list_for_anchor_by('publication', $anchors, 0, $count, $layout);

		// scope is limited to one category
		} elseif(strpos($anchor, 'category:') === 0) {

			// first level of depth
			$anchors = array();

			// get sections linked to this category
			if($topics =& Members::list_sections_by_title_for_anchor($anchor, 0, 50, 'raw')) {
				foreach($topics as $id => $not_used)
					$anchors = array_merge($anchors, array('section:'.$id));
			}

			// second level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($anchors, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// third level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($anchors, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// fourth level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($anchors, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// fifth level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($anchors, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// the category itself is an anchor
			$anchors[] = $anchor;

			// ensure anchors are referenced only once
			$anchors = array_unique($anchors);

			// query the database and layout that stuff
			$text =& Members::list_articles_by_date_for_anchor($anchors, 0, $count, $layout);

		// scope is limited to one author
		} elseif(strpos($anchor, 'user:') === 0)
			$text =& Articles::list_for_author_by('publication', str_replace('user:', '', $anchor), 0, $count, $layout);

		// consider all pages
		else
			$text =& Articles::list_by('publication', 0, $count, $layout);

		// we have an array to format
		if(is_array($text))
			$text =& Skin::build_list($text, $layout);

		// job done
		return $text;
	}

	/**
	 * select a random page
	 *
	 * The provided anchor can reference:
	 * - a section 'section:123'
	 * - a category 'category:456'
	 * - a user 'user:789'
	 * - 'self'
	 * - nothing
	 *
	 * @param string the anchor (e.g. 'section:123')
	 * @param string layout to use
	 * @return string the rendered text
	**/
	function &render_random($anchor='', $layout='') {
		global $context;

		// we return some text;
		$text = '';

		// label is explicit
		$label = '';
		if($position = strrpos($anchor, ',')) {
			$label = trim(substr($anchor, $position+1));
			$anchor = trim(substr($anchor, 0, $position));
		}

		// scope is limited to current surfer
		if(($anchor == 'self') && Surfer::get_id()) {
			$anchor = 'user:'.Surfer::get_id();

			// refresh on every page load
			Cache::poison();

		}

		// scope is limited to one section
		if(!strncmp($anchor, 'section:', 8)) {

			// look at this level
			$anchors = array($anchor);

			// first level of depth
			$topics =& Sections::get_children_of_anchor($anchor, 'main');
			$anchors = array_merge($anchors, $topics);

			// second level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($topics, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// third level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($topics, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// fourth level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($topics, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// fifth level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($topics, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// query the database and layout that stuff
			$items =& Articles::list_for_anchor_by('random', $anchors, 0, 1, 'raw');

		// scope is limited to one author
		} elseif(!strncmp($anchor, 'user:', 5))
			$items =& Articles::list_for_author_by('random', str_replace('user:', '', $anchor), 0, 1, 'raw');

		// consider all pages
		else
			$items =& Articles::list_by('random', 0, 1, 'raw');

		// we have an array to format
 		if($items) {
 			foreach($items as $id => $item) {

				// make a link to the target page
				$link =& Articles::get_permalink($item);
				if(!$label)
					$label = Skin::strip($item['title']);
				$text =& Skin::build_link($link, $label, 'article');

				if($layout == 'description') {

					// the introduction text, if any
					$text .= BR.Codes::beautify($item['introduction']);

					// load overlay, if any
					if(isset($item['overlay']) && $item['overlay']) {
						include_once '../overlays/overlay.php';
						$overlay = Overlay::load($item);

						// get text related to the overlay, if any
						if(is_object($overlay))
							$text .= $overlay->get_text('view', $item);

					}

					// the description, which is the actual page body
					$text .= '<div>'.Codes::beautify($item['description']).'</div>';

				}

				// we take only one item
				break;
			}
 		}

		// job done
		return $text;
	}

	/**
	 * render a compact list of hits
	 *
	 * @param string the anchor (e.g. 'section:123')
	 * @param string layout to use
	 * @return string the rendered text
	**/
	function &render_read($anchor='', $layout='hits') {
		global $context;

		// we return some text;
		$text = '';

		// number of items to display
		$count = COMPACT_LIST_SIZE;
		if(($position = strpos($anchor, ',')) !== FALSE) {
			$count = (integer)trim(substr($anchor, $position+1));
			if(!$count)
				$count = COMPACT_LIST_SIZE;

			$anchor = trim(substr($anchor, 0, $position));
		}

		// scope is limited to current surfer
		if(($anchor == 'self') && Surfer::get_id()) {
			$anchor = 'user:'.Surfer::get_id();

			// refresh on every page load
			Cache::poison();

		}

		// scope is limited to one section
		if(strpos($anchor, 'section:') === 0) {

			// look at this level
			$anchors = array($anchor);

			// first level of depth
			$topics =& Sections::get_children_of_anchor($anchor, 'main');
			$anchors = array_merge($anchors, $topics);

			// second level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($topics, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// third level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($topics, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// fourth level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($topics, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// fifth level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($topics, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// query the database and layout that stuff
			$text =& Articles::list_for_anchor_by('hits', $anchors, 0, $count, $layout);

		// scope is limited to pages of one surfer
		} elseif(strpos($anchor, 'user:') === 0)
			$text =& Articles::list_for_user_by('hits', substr($anchor, 5), 0, $count, $layout);

		// consider all pages
		if(!$text)
			$text =& Articles::list_by('hits', 0, $count, $layout);

		// we have an array to format
		if(is_array($text))
			$text =& Skin::build_list($text, $layout);

		// job done
		return $text;
	}

	/**
	 * render tweetmeme button
	 *
	 * @return string the rendered text
	**/
	function &render_retweet() {
		global $context;

		// we return some text --$context['self_url'] already has $context['url_to_root'] in it
		$text = JS_PREFIX
			.'tweetmeme_url = "'.$context['url_to_home'].$context['self_url'].'";'."\n"
			.JS_SUFFIX
			.'<script type="text/javascript" src="http://tweetmeme.com/i/scripts/button.js"></script>';

		// job done
		return $text;
	}

	/**
	 * render a list of sections
	 *
	 * The provided anchor can reference:
	 * - a section 'section:123'
	 * - a user 'user:789'
	 * - 'self'
	 * - nothing
	 *
	 * @param string the anchor (e.g. 'section:123')
	 * @param string layout to use
	 * @return string the rendered text
	**/
	function &render_sections($anchor='', $layout='simple') {
		global $context;

		// we return some text;
		$text = '';

		// number of items to display
		$count = YAHOO_LIST_SIZE;
		if(($position = strpos($anchor, ',')) !== FALSE) {
			$count = (integer)trim(substr($anchor, $position+1));
			if(!$count)
				$count = YAHOO_LIST_SIZE;

			$anchor = trim(substr($anchor, 0, $position));
		}

		// scope is limited to current surfer
		if(($anchor == 'self') && Surfer::get_id()) {
			$anchor = 'user:'.Surfer::get_id();

			// refresh on every page load
			Cache::poison();

		}

		// scope is limited to one section
		if(strpos($anchor, 'section:') === 0)
			$text =& Sections::list_by_title_for_anchor($anchor, 0, $count, $layout);

		// scope is limited to one author
		elseif(strpos($anchor, 'user:') === 0)
			$text =& Members::list_sections_by_title_for_anchor($anchor, 0, $count, $layout);

		// consider all pages
		else
			$text =& Sections::list_by_title_for_anchor(NULL, 0, $count, $layout);

		// we have an array to format
		if(is_array($text))
			$text =& Skin::build_list($text, $layout);

		// job done
		return $text;
	}

	/**
	 * render a table
	 *
	 * @param string the table content
	 * @param string the variant, if any
	 * @return string the rendered text
	**/
	function render_static_table($content, $variant='') {
		global $context;

		// we are providing inline tables
		if($variant)
			$variant = 'inline '.$variant;
		else
			$variant = 'inline';

		// do we have headers to proceed?
		$in_body = !preg_match('/\[body\]/i', $content);

		// start at first line, except if headers have to be printed first
		if($in_body)
			$count = 1;
		else
			$count = 2;

		// split lines
		$rows = explode("\n", $content);
		if(!is_array($rows))
			return '';

		// one row per line - cells are separated by |, \t, or 2 spaces
		$text =& Skin::table_prefix($variant);
		foreach($rows as $row) {

			// skip blank lines
			if(!$row)
				continue;

			// header row
			if(!$in_body) {
				if(preg_match('/\[body\]/i', $row))
					$in_body = true;
				else
					$text .= Skin::table_row(preg_split("/([\|\t]| "." )/", $row), 'header');

			// body row
			} else
				$text .= Skin::table_row(preg_split("/([\|\t]| "." )/", $row), $count++);

		}

		// return the complete table
		$text .= Skin::table_suffix();
		return $text;
	}

	/**
	 * render a table of links
	 *
	 * @param string the variant
	 * @return string the rendered text
	**/
	function &render_table_of($variant) {
		global $context;

		// nothing to return yet
		$output = '';

		// list of questions for a FAQ
		if($variant == 'questions') {

			// only if the table is not empty
			global $codes_toq;
			if(isset($codes_toq) && $codes_toq) {

				// to be rendered by css, using selector .toq_box ul, etc.
				$text = '<ul>'."\n";
				foreach($codes_toq as $link)
					$text .= '<li>'.$link.'</li>'."\n";
				$text .= '</ul>'."\n";

				$output =& Skin::build_box('', $text, 'toq');

			}

		// list of titles
		} else {

			// only if the table is not empty
			global $codes_toc;
			if(isset($codes_toc) && $codes_toc) {

				// to be rendered by css, using selector .toc_box ul, etc.
				// <ul>
				// <li>1. link</li> 		0 -> 1
				// <li>1. link				1 -> 1
				//		<ul>
				//		<li>2. link</li>	1 -> 2
				//		<li>2. link</li>	2 -> 2
				//		</ul></li>
				// <li>1. link		 		2 -> 1
				//		<ul>
				//		<li>2. link</li>	1 -> 2
				//		<li>2. link</li>	2 -> 2
				//		</ul></li>
				// </ul>
				$text ='';
				$previous_level = 0;
				foreach($codes_toc as $attributes) {
					list($level, $link) = $attributes;

					if($previous_level == $level)
						$text .= '</li>'."\n";

					else {

						if($previous_level < $level) {
							$text .= '<ul>';
							$previous_level++;
							while($previous_level < $level) {
								$text .= '<li><ul>'."\n";
								$previous_level++;
							}
						}

						if($previous_level > $level) {
							$text .= '</li>';
							while($previous_level > $level) {
								$text .= '</ul></li>'."\n";
								$previous_level--;
							}
						}
					}

					$text .= '<li>'.$link;

				}

				if($previous_level > 0) {
					$text .= '</li>';
					while($previous_level > 0) {
						if($previous_level > 1)
							$text .= '</ul></li>'."\n";
						else
							$text .= '</ul>'."\n";
						$previous_level--;
					}
				}

				$output =& Skin::build_box('', $text, 'toc');

			}

		}

		return $output;
	}

	/**
	 * render a title, a sub-title, or a question
	 *
	 * @param string the text
	 * @param string the variant
	 * @return string the rendered text
	**/
	function &render_title($text, $variant) {
		global $codes_toc, $codes_toq, $context;

		// remember questions
		if($variant == 'question') {
			$index = count($codes_toq)+1;
			$id = 'question_'.$index;
			$url = $context['self_url'].'#'.$id;
			$codes_toq[] = Skin::build_link($url, ucfirst($text), 'basic');
			$text = QUESTION_FLAG.$text;

		// remember level 1 titles ([title]...[/title] or [header1]...[/header1])
		} elseif($variant == 'header1') {
			$index = count($codes_toc)+1;
			$id = 'title_'.$index;
			$url = $context['self_url'].'#'.$id;
			$codes_toc[] = array(1, Skin::build_link($url, ucfirst($text), 'basic'));

		// remember level 2 titles ([subtitle]...[/subtitle] or [header2]...[/header2])
		} elseif($variant == 'header2') {
			$index = count($codes_toc)+1;
			$id = 'title_'.$index;
			$url = $context['self_url'].'#'.$id;
			$codes_toc[] = array(2, Skin::build_link($url, ucfirst($text), 'basic'));

		// remember level 3 titles
		} elseif($variant == 'header3') {
			$index = count($codes_toc)+1;
			$id = 'title_'.$index;
			$url = $context['self_url'].'#'.$id;
			$codes_toc[] = array(3, Skin::build_link($url, ucfirst($text), 'basic'));

		// remember level 4 titles
		} elseif($variant == 'header4') {
			$index = count($codes_toc)+1;
			$id = 'title_'.$index;
			$url = $context['self_url'].'#'.$id;
			$codes_toc[] = array(4, Skin::build_link($url, ucfirst($text), 'basic'));

		// remember level 5 titles
		} elseif($variant == 'header5') {
			$index = count($codes_toc)+1;
			$id = 'title_'.$index;
			$url = $context['self_url'].'#'.$id;
			$codes_toc[] = array(5, Skin::build_link($url, ucfirst($text), 'basic'));
		}

		// the rendered text
		$output =& Skin::build_block($text, $variant, $id);
		return $output;
	}

	/**
	 * render twitter profile
	 *
	 * @param string twitter id to display, plus optional parameters, if any
	 * @return string the rendered text
	**/
	function &render_twitter($id) {
		global $context;

		// up to 4 parameters: id, width, height, styles
		$attributes = preg_split("/\s*,\s*/", $id, 4);
		$id = $attributes[0];

		// width
		if(isset($attributes[1]))
			$width = $attributes[1];
		else
			$width = 250;

		// height
		if(isset($attributes[2]))
			$height = $attributes[2];
		else
			$height = 300;

		// theme
		if(isset($attributes[3]))
			$theme = $attributes[3];
		else
			$theme = 'theme: { shell: {'."\n"
				.'      background: "#3082af",'."\n"
				.'      color: "#ffffff"'."\n"
				.'    },'."\n"
				.'    tweets: {'."\n"
				.'      background: "#ffffff",'."\n"
				.'      color: "#444444",'."\n"
				.'      links: "#1985b5"'."\n"
				.'    }}';

		// allow multiple widgets
		static $count;
		if(!isset($count))
			$count = 1;
		else
			$count++;

		// we return some text --$context['self_url'] already has $context['url_to_root'] in it
		$text = '<div id="twitter_'.$count.'"></div>'."\n"
			.'<script src="http://widgets.twimg.com/j/1/widget.js" type="text/javascript"></script>'."\n"
			.'<link href="http://widgets.twimg.com/j/1/widget.css" type="text/css" rel="stylesheet" />'."\n"
			.'<script type="text/javascript">'."\n"
			.'new TWTR.Widget({'."\n"
			.'  profile: true,'."\n"
			.'  id: "twitter_'.$count.'",'."\n"
			.'  loop: true,'."\n"
			.'  width: '.$width.','."\n"
			.'  height: '.$height.','."\n"
			.'  '.$theme."\n"
			.'}).render().setProfile("'.$id.'").start();'."\n"
			.'</script>';

		// job done
		return $text;
	}

	/**
	 * render twitter search
	 *
	 * @param string twitter searched keywords, plus optional parameters, if any
	 * @return string the rendered text
	**/
	function &render_twitter_search($id) {
		global $context;

		// up to 4 parameters: id, width, height, styles
		$attributes = preg_split("/\s*,\s*/", $id, 4);
		$id = $attributes[0];

		// width
		if(isset($attributes[1]))
			$width = $attributes[1];
		else
			$width = 250;

		// height
		if(isset($attributes[2]))
			$height = $attributes[2];
		else
			$height = 300;

		// theme
		if(isset($attributes[3]))
			$theme = $attributes[3];
		else
			$theme = 'theme: { shell: {'."\n"
				.'      background: "#3082af",'."\n"
				.'      color: "#ffffff"'."\n"
				.'    },'."\n"
				.'    tweets: {'."\n"
				.'      background: "#ffffff",'."\n"
				.'      color: "#444444",'."\n"
				.'      links: "#1985b5"'."\n"
				.'    }}';

		// allow multiple widgets
		static $count;
		if(!isset($count))
			$count = 1;
		else
			$count++;

		// $context['self_url'] already has $context['url_to_root'] in it
		$text = '<div id="tsearch_'.$count.'"></div>'."\n"
			.'<script src="http://widgets.twimg.com/j/1/widget.js" type="text/javascript"></script>'."\n"
			.'<link href="http://widgets.twimg.com/j/1/widget.css" type="text/css" rel="stylesheet" />'."\n"
			.'<script type="text/javascript">'."\n"
			.'new TWTR.Widget({'."\n"
			.'  search: "'.str_replace('"', '', $id).'",'."\n"
			.'  id: "tsearch_'.$count.'",'."\n"
			.'  loop: true,'."\n"
			.'  width: '.$width.','."\n"
			.'  height: '.$height.','."\n"
			.'  '.$theme."\n"
			.'}).render().start();'."\n"
			.'</script>';

		// job done
		return $text;
	}

	/**
	 * render a compact list of recent modifications
	 *
	 * The provided anchor can reference:
	 * - a section 'section:123'
	 * - a category 'category:456'
	 * - a user 'user:789'
	 * - 'self'
	 * - nothing
	 *
	 * @param string the anchor (e.g. 'section:123')
	 * @param string layout to use
	 * @return string the rendered text
	**/
	function &render_updated($anchor='', $layout='compact') {
		global $context;

		// we return some text;
		$text = '';

		// number of items to display
		$count = COMPACT_LIST_SIZE;
		if(($position = strpos($anchor, ',')) !== FALSE) {
			$count = (integer)trim(substr($anchor, $position+1));
			if(!$count)
				$count = COMPACT_LIST_SIZE;

			$anchor = trim(substr($anchor, 0, $position));
		}

		// scope is limited to current surfer
		if(($anchor == 'self') && Surfer::get_id()) {
			$anchor = 'user:'.Surfer::get_id();

			// refresh on every page load
			Cache::poison();

		}

		// scope is limited to one section
		if(strpos($anchor, 'section:') === 0) {

			// look at this level
			$anchors = array($anchor);

			// first level of depth
			$topics =& Sections::get_children_of_anchor($anchor, 'main');
			$anchors = array_merge($anchors, $topics);

			// second level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($topics, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// third level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($topics, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// fourth level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($topics, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// fifth level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($topics, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// query the database and layout that stuff
			$text =& Articles::list_for_anchor_by('edition', $anchors, 0, $count, $layout);

		// scope is limited to one category
		} elseif(strpos($anchor, 'category:') === 0) {

			// first level of depth
			$anchors = array();

			// get sections linked to this category
			if($topics =& Members::list_sections_by_title_for_anchor($anchor, 0, 50, 'raw')) {
				foreach($topics as $id => $not_used)
					$anchors = array_merge($anchors, array('section:'.$id));
			}

			// second level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($anchors, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// third level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($anchors, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// fourth level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($anchors, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// fifth level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($anchors, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// the category itself is an anchor
			$anchors[] = $anchor;

			// ensure anchors are referenced only once
			$anchors = array_unique($anchors);

			// query the database and layout that stuff
			$text =& Members::list_articles_by_date_for_anchor($anchors, 0, $count, $layout);

		// scope is limited to pages of one surfer
		} elseif(strpos($anchor, 'user:') === 0)
			$text =& Articles::list_for_user_by('edition', substr($anchor, 5), 0, $count, $layout);

		// consider all pages
		else
			$text =& Articles::list_by('edition', 0, $count, $layout);

		// we have an array to format
		if(is_array($text))
			$text =& Skin::build_list($text, $layout);

		// job done
		return $text;
	}

	/**
	 * render a compact list of users present on site
	 *
	 * @param string the anchor (e.g. 'present')
	 * @return string the rendered text
	**/
	function &render_users($anchor='') {
		global $context;

		// we return some text;
		$text = '';

		// number of items to display
		$count = COMPACT_LIST_SIZE;
		if(($position = strpos($anchor, ',')) !== FALSE) {
			$count = (integer)trim(substr($anchor, $position+1));
			if(!$count)
				$count = COMPACT_LIST_SIZE;

			$anchor = trim(substr($anchor, 0, $position));
		}

	    //  the list of users present on the site
    	$text = Users::list_present(0, $count, 'compact');

	  	// also mention the total number of users present, if larger than the number of users displayed
  		$stat = Users::stat_present();
	  	if($stat['count'] > $count)
  			$text = array_merge($text, array('_' => sprintf(i18n::ns('%d active now', '%d active now', $stat['count']), $stat['count'])));

		// we have an array to format
		if(is_array($text))
			$text =& Skin::build_list($text, 'compact');

		// job done
		return $text;
	}

	/**
	 * render a compact list of voted pages
	 *
	 * @param string the anchor (e.g. 'section:123')
	 * @param string layout to use
	 * @return string the rendered text
	**/
	function &render_voted($anchor='', $layout='simple') {
		global $context;

		// we return some text;
		$text = '';

		// number of items to display
		$count = COMPACT_LIST_SIZE;
		if(($position = strpos($anchor, ',')) !== FALSE) {
			$count = (integer)trim(substr($anchor, $position+1));
			if(!$count)
				$count = COMPACT_LIST_SIZE;

			$anchor = trim(substr($anchor, 0, $position));
		}

		// scope is limited to current surfer
		if(($anchor == 'self') && Surfer::get_id()) {
			$anchor = 'user:'.Surfer::get_id();

			// refresh on every page load
			Cache::poison();

		}

		// scope is limited to one section
		if(strpos($anchor, 'section:') === 0) {

			// look at this level
			$anchors = array($anchor);

			// first level of depth
			$topics =& Sections::get_children_of_anchor($anchor, 'main');
			$anchors = array_merge($anchors, $topics);

			// second level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($topics, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// third level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($topics, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// fourth level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($topics, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// fifth level of depth
			if(count($topics) && (count($anchors) < 2000)) {
				$topics =& Sections::get_children_of_anchor($topics, 'main');
				$anchors = array_merge($anchors, $topics);
			}

			// query the database and layout that stuff
			$text =& Articles::list_for_anchor_by('rating', $anchors, 0, $count, $layout);

		// scope is limited to pages of one surfer
		} elseif(strpos($anchor, 'user:') === 0)
			$text =& Articles::list_for_user_by('rating', substr($anchor, 5), 0, $count, $layout);

		// consider all pages
		else
			$text =& Articles::list_by('rating', 0, $count, $layout);

		// we have an array to format
		if(is_array($text))
			$text =& Skin::build_list($text, $layout);

		// job done
		return $text;
	}

	/**
	 * render a link to Wikipedia
	 *
	 * @param string the id, with possible options or variant
	 * @return string the rendered text
	**/
	function &render_wikipedia($id) {
		global $context;

		// maybe an alternate title has been provided
		$attributes = preg_split("/\s*,\s*/", $id, 2);
		$id = $attributes[0];

		// ensure we have a label for this link
		if(isset($attributes[1]))
			$text = $attributes[1];
		else
			$text = '';

		// select the language
		$language = $context['preferred_language'];

		// take the navigator language if possible
		if (isset($context['language']) && $context['without_language_detection']=='N')
			$language = $context['language'];

		// make a link to the target page
		$url = 'http://'.$language.'.wikipedia.org/wiki/Special:Search?search='.preg_replace('[\s]', '_', $id);

		// return a complete anchor
		$output =& Skin::build_link($url, $text, 'wikipedia');
		return $output;

	}


	/**
	 * remove YACS codes from a string
	 *
	 * @param string embedding YACS codes
	 * @return a purged string
	 */
	function &strip($text, $suppress_all_brackets=FALSE) {
		global $context;

		// suppress pairing codes
		$output = preg_replace('/\[(\w+?)[^\]]*\](.*?)\[\/\1\]/s', '${2}', $text);

		// suppress bracketed words
		if($suppress_all_brackets)
			$output = trim(preg_replace('/\[(.+?)\]/s', ' ', $output));

		return $output;
	}
}

?>