/helpers/library/HTMLPurifier/Generator.php

<?php



/**

 * Generates HTML from tokens.

 * @todo Refactor interface so that configuration/context is determined

 *       upon instantiation, no need for messy generateFromTokens() calls

 * @todo Make some of the more internal functions protected, and have

 *       unit tests work around that

 */

class HTMLPurifier_Generator

{



    /**

     * Whether or not generator should produce XML output

     */

    private $_xhtml = true;



    /**

     * :HACK: Whether or not generator should comment the insides of <script> tags

     */

    private $_scriptFix = false;



    /**

     * Cache of HTMLDefinition during HTML output to determine whether or

     * not attributes should be minimized.

     */

    private $_def;



    /**

     * Cache of %Output.SortAttr

     */

    private $_sortAttr;



    /**

     * Cache of %Output.FlashCompat

     */

    private $_flashCompat;



    /**

     * Cache of %Output.FixInnerHTML

     */

    private $_innerHTMLFix;



    /**

     * Stack for keeping track of object information when outputting IE

     * compatibility code.

     */

    private $_flashStack = array();



    /**

     * Configuration for the generator

     */

    protected $config;



    /**

     * @param $config Instance of HTMLPurifier_Config

     * @param $context Instance of HTMLPurifier_Context

     */

    public function __construct($config, $context) {

        $this->config = $config;

        $this->_scriptFix = $config->get('Output.CommentScriptContents');

        $this->_innerHTMLFix = $config->get('Output.FixInnerHTML');

        $this->_sortAttr = $config->get('Output.SortAttr');

        $this->_flashCompat = $config->get('Output.FlashCompat');

        $this->_def = $config->getHTMLDefinition();

        $this->_xhtml = $this->_def->doctype->xml;

    }



    /**

     * Generates HTML from an array of tokens.

     * @param $tokens Array of HTMLPurifier_Token

     * @param $config HTMLPurifier_Config object

     * @return Generated HTML

     */

    public function generateFromTokens($tokens) {

        if (!$tokens) return '';



        // Basic algorithm

        $html = '';

        for ($i = 0, $size = count($tokens); $i < $size; $i++) {

            if ($this->_scriptFix && $tokens[$i]->name === 'script'

                && $i + 2 < $size && $tokens[$i+2] instanceof HTMLPurifier_Token_End) {

                // script special case

                // the contents of the script block must be ONE token

                // for this to work.

                $html .= $this->generateFromToken($tokens[$i++]);

                $html .= $this->generateScriptFromToken($tokens[$i++]);

            }

            $html .= $this->generateFromToken($tokens[$i]);

        }



        // Tidy cleanup

        if (extension_loaded('tidy') && $this->config->get('Output.TidyFormat')) {

            $tidy = new Tidy;

            $tidy->parseString($html, array(

               'indent'=> true,

               'output-xhtml' => $this->_xhtml,

               'show-body-only' => true,

               'indent-spaces' => 2,

               'wrap' => 68,

            ), 'utf8');

            $tidy->cleanRepair();

            $html = (string) $tidy; // explicit cast necessary

        }



        // Normalize newlines to system defined value

        if ($this->config->get('Core.NormalizeNewlines')) {

            $nl = $this->config->get('Output.Newline');

            if ($nl === null) $nl = PHP_EOL;

            if ($nl !== "\n") $html = str_replace("\n", $nl, $html);

        }

        return $html;

    }



    /**

     * Generates HTML from a single token.

     * @param $token HTMLPurifier_Token object.

     * @return Generated HTML

     */

    public function generateFromToken($token) {

        if (!$token instanceof HTMLPurifier_Token) {

            trigger_error('Cannot generate HTML from non-HTMLPurifier_Token object', E_USER_WARNING);

            return '';



        } elseif ($token instanceof HTMLPurifier_Token_Start) {

            $attr = $this->generateAttributes($token->attr, $token->name);

            if ($this->_flashCompat) {

                if ($token->name == "object") {

                    $flash = new stdclass();

                    $flash->attr = $token->attr;

                    $flash->param = array();

                    $this->_flashStack[] = $flash;

                }

            }

            return '<' . $token->name . ($attr ? ' ' : '') . $attr . '>';



        } elseif ($token instanceof HTMLPurifier_Token_End) {

            $_extra = '';

            if ($this->_flashCompat) {

                if ($token->name == "object" && !empty($this->_flashStack)) {

                    // doesn't do anything for now

                }

            }

            return $_extra . '</' . $token->name . '>';



        } elseif ($token instanceof HTMLPurifier_Token_Empty) {

            if ($this->_flashCompat && $token->name == "param" && !empty($this->_flashStack)) {

                $this->_flashStack[count($this->_flashStack)-1]->param[$token->attr['name']] = $token->attr['value'];

            }

            $attr = $this->generateAttributes($token->attr, $token->name);

             return '<' . $token->name . ($attr ? ' ' : '') . $attr .

                ( $this->_xhtml ? ' /': '' ) // <br /> v. <br>

                . '>';



        } elseif ($token instanceof HTMLPurifier_Token_Text) {

            return $this->escape($token->data, ENT_NOQUOTES);



        } elseif ($token instanceof HTMLPurifier_Token_Comment) {

            return '<!--' . $token->data . '-->';

        } else {

            return '';



        }

    }



    /**

     * Special case processor for the contents of script tags

     * @warning This runs into problems if there's already a literal

     *          --> somewhere inside the script contents.

     */

    public function generateScriptFromToken($token) {

        if (!$token instanceof HTMLPurifier_Token_Text) return $this->generateFromToken($token);

        // Thanks <http://lachy.id.au/log/2005/05/script-comments>

        $data = preg_replace('#//\s*$#', '', $token->data);

        return '<!--//--><![CDATA[//><!--' . "\n" . trim($data) . "\n" . '//--><!]]>';

    }



    /**

     * Generates attribute declarations from attribute array.

     * @note This does not include the leading or trailing space.

     * @param $assoc_array_of_attributes Attribute array

     * @param $element Name of element attributes are for, used to check

     *        attribute minimization.

     * @return Generate HTML fragment for insertion.

     */

    public function generateAttributes($assoc_array_of_attributes, $element = false) {

        $html = '';

        if ($this->_sortAttr) ksort($assoc_array_of_attributes);

        foreach ($assoc_array_of_attributes as $key => $value) {

            if (!$this->_xhtml) {

                // Remove namespaced attributes

                if (strpos($key, ':') !== false) continue;

                // Check if we should minimize the attribute: val="val" -> val

                if ($element && !empty($this->_def->info[$element]->attr[$key]->minimized)) {

                    $html .= $key . ' ';

                    continue;

                }

            }

            // Workaround for Internet Explorer innerHTML bug.

            // Essentially, Internet Explorer, when calculating

            // innerHTML, omits quotes if there are no instances of

            // angled brackets, quotes or spaces.  However, when parsing

            // HTML (for example, when you assign to innerHTML), it

            // treats backticks as quotes.  Thus,

            //      <img alt="``" />

            // becomes

            //      <img alt=`` />

            // becomes

            //      <img alt='' />

            // Fortunately, all we need to do is trigger an appropriate

            // quoting style, which we do by adding an extra space.

            // This also is consistent with the W3C spec, which states

            // that user agents may ignore leading or trailing

            // whitespace (in fact, most don't, at least for attributes

            // like alt, but an extra space at the end is barely

            // noticeable).  Still, we have a configuration knob for

            // this, since this transformation is not necesary if you

            // don't process user input with innerHTML or you don't plan

            // on supporting Internet Explorer.

            if ($this->_innerHTMLFix) {

                if (strpos($value, '`') !== false) {

                    // check if correct quoting style would not already be

                    // triggered

                    if (strcspn($value, '"\' <>') === strlen($value)) {

                        // protect!

                        $value .= ' ';

                    }

                }

            }

            $html .= $key.'="'.$this->escape($value).'" ';

        }

        return rtrim($html);

    }



    /**

     * Escapes raw text data.

     * @todo This really ought to be protected, but until we have a facility

     *       for properly generating HTML here w/o using tokens, it stays

     *       public.

     * @param $string String data to escape for HTML.

     * @param $quote Quoting style, like htmlspecialchars. ENT_NOQUOTES is

     *               permissible for non-attribute output.

     * @return String escaped data.

     */

    public function escape($string, $quote = null) {

        // Workaround for APC bug on Mac Leopard reported by sidepodcast

        // http://htmlpurifier.org/phorum/read.php?3,4823,4846

        if ($quote === null) $quote = ENT_COMPAT;

        return htmlspecialchars($string, $quote, 'UTF-8');

    }



}



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