/plugins/com_acymailing_starter_2.0.0_2011-07-06/front/inc/emogrifier/emogrifier.php

<?php defined('_JEXEC') or die('Restricted access'); ?>

<?php

/*

UPDATES

    2008-08-10  Fixed CSS comment stripping regex to add PCRE_DOTALL (changed from '/\/\*.*\*\//U' to '/\/\*.*\*\//sU')

    2008-08-18  Added lines instructing DOMDocument to attempt to normalize HTML before processing

    2008-10-20  Fixed bug with bad variable name... Thanks Thomas!

    2008-03-02  Added licensing terms under the MIT License

                Only remove unprocessable HTML tags if they exist in the array

    2009-06-03  Normalize existing CSS (style) attributes in the HTML before we process the CSS.

                Made it so that the display:none stripper doesn't require a trailing semi-colon.

    2009-08-13  Added support for subset class values (e.g. "p.class1.class2").

                Added better protection for bad css attributes.

                Fixed support for HTML entities.

    2009-08-17  Fixed CSS selector processing so that selectors are processed by precedence/specificity, and not just in order.

    2009-10-29  Fixed so that selectors appearing later in the CSS will have precedence over identical selectors appearing earlier.

    2009-11-04  Explicitly declared static functions static to get rid of E_STRICT notices.

    2010-05-18  Fixed bug where full url filenames with protocols wouldn't get split improperly when we explode on ':'... Thanks Mark!

                Added two new attribute selectors

    2010-06-16  Added static caching for less processing overhead in situations where multiple emogrification takes place

    2010-07-26  Fixed bug where '0' values were getting discarded because of php's empty() function... Thanks Scott!

    2010-09-03  Added checks to invisible node removal to ensure that we don't try to remove non-existent child nodes of parents that have already been deleted





*/

class Emogrifier {



    private $html = '';

    private $css = '';

    private $unprocessableHTMLTags = array('wbr');



    public function __construct($html = '', $css = '') {

        $this->html = $html;

        $this->css  = $css;

    }



    public function setHTML($html = '') { $this->html = $html; }

    public function setCSS($css = '') { $this->css = $css; }



	// there are some HTML tags that DOMDocument cannot process, and will throw an error if it encounters them.

	// these functions allow you to add/remove them if necessary.

	// it only strips them from the code (does not remove actual nodes).

    public function addUnprocessableHTMLTag($tag) { $this->unprocessableHTMLTags[] = $tag; }

    public function removeUnprocessableHTMLTag($tag) {

        if (($key = array_search($tag,$this->unprocessableHTMLTags)) !== false)

            unset($this->unprocessableHTMLTags[$key]);

    }



    // applies the CSS you submit to the html you submit. places the css inline

	public function emogrify() {

	    $body = $this->html;

	    // process the CSS here, turning the CSS style blocks into inline css

	    if (count($this->unprocessableHTMLTags)) {

            $unprocessableHTMLTags = implode('|',$this->unprocessableHTMLTags);

            $body = preg_replace("/<($unprocessableHTMLTags)[^>]*>/i",'',$body);

	    }



        //$encoding = mb_detect_encoding($body);

        $encoding = 'UTF-8';

        $body = mb_convert_encoding($body, 'HTML-ENTITIES', $encoding);



        $xmldoc =@ new DOMDocument;

        if(!is_object($xmldoc) || !method_exists($xmldoc,'loadHTML')) return $this->html;



		$xmldoc->encoding = $encoding;

		$xmldoc->strictErrorChecking = false;

		$xmldoc->formatOutput = true;

        //ACYBA MODIFICATION : let's avoid some warnings

        @$xmldoc->loadHTML($body);

		$xmldoc->normalizeDocument();



		$xpath = new DOMXPath($xmldoc);



        // before be begin processing the CSS file, parse the document and normalize all existing CSS attributes (changes 'DISPLAY: none' to 'display: none');

        // we wouldn't have to do this if DOMXPath supported XPath 2.0.

        $nodes = @$xpath->query('//*[@style]');

        if ($nodes->length > 0) foreach ($nodes as $node) $node->setAttribute('style',preg_replace('/[A-z\-]+(?=\:)/Se',"strtolower('\\0')",$node->getAttribute('style')));



		// get rid of css comment code

		$re_commentCSS = '/\/\*.*\*\//sU';

		$css = preg_replace($re_commentCSS,'',$this->css);



        static $csscache = array();

        $csskey = md5($css);

        if (!isset($csscache[$csskey])) {



            // process the CSS file for selectors and definitions

            $re_CSS = '/^\s*([^{]+){([^}]+)}/mis';

            preg_match_all($re_CSS,$css,$matches);



            $all_selectors = array();

            foreach ($matches[1] as $key => $selectorString) {

                // if there is a blank definition, skip

                if (!strlen(trim($matches[2][$key]))) continue;



                // else split by commas and duplicate attributes so we can sort by selector precedence

                $selectors = explode(',',$selectorString);

                foreach ($selectors as $selector) {

                    // don't process pseudo-classes

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

                    $all_selectors[] = array('selector' => $selector,

                                             'attributes' => $matches[2][$key],

                                             'index' => $key, // keep track of where it appears in the file, since order is important

                    );

                }

            }



            // now sort the selectors by precedence

            usort($all_selectors, array('self','sortBySelectorPrecedence'));



            $csscache[$csskey] = $all_selectors;

        }



        foreach ($csscache[$csskey] as $value) {



            // query the body for the xpath selector

            $nodes = @$xpath->query($this->translateCSStoXpath(trim($value['selector'])));

			if(empty($nodes)) continue;



            foreach($nodes as $node) {

                // if it has a style attribute, get it, process it, and append (overwrite) new stuff

                if ($node->hasAttribute('style')) {

                    // break it up into an associative array

                    $oldStyleArr = $this->cssStyleDefinitionToArray($node->getAttribute('style'));

                    $newStyleArr = $this->cssStyleDefinitionToArray($value['attributes']);



                    // new styles overwrite the old styles (not technically accurate, but close enough)

                    $combinedArr = array_merge($oldStyleArr,$newStyleArr);

                    $style = '';

                    foreach ($combinedArr as $k => $v) $style .= (strtolower($k) . ':' . $v . ';');

                } else {

                    // otherwise create a new style

                    $style = trim($value['attributes']);

                }

                $node->setAttribute('style',$style);

            }

        }



		// This removes styles from your email that contain display:none. You could comment these out if you want.

        $nodes = $xpath->query('//*[contains(translate(@style," ",""),"display:none")]');

        // the checks on parentNode and is_callable below are there to ensure that if we've deleted the parent node,

        // we don't try to call removeChild on a nonexistent child node

        if ($nodes->length > 0) foreach ($nodes as $node) if ($node->parentNode && is_callable(array($node->parentNode,'removeChild'))) $node->parentNode->removeChild($node);



		return $this->fixCompatibility($xmldoc->saveHTML());



	}



    private static function sortBySelectorPrecedence($a, $b) {

        $precedenceA = self::getCSSSelectorPrecedence($a['selector']);

        $precedenceB = self::getCSSSelectorPrecedence($b['selector']);



        // we want these sorted ascendingly so selectors with lesser precedence get processed first and

        // selectors with greater precedence get sorted last

        return ($precedenceA == $precedenceB) ? ($a['index'] < $b['index'] ? -1 : 1) : ($precedenceA < $precedenceB ? -1 : 1);

    }



    private static function getCSSSelectorPrecedence($selector) {

        static $selectorcache = array();

        $selectorkey = md5($selector);

        if (!isset($selectorcache[$selectorkey])) {

            $precedence = 0;

            $value = 100;

            $search = array('\#','\.',''); // ids: worth 100, classes: worth 10, elements: worth 1



            foreach ($search as $s) {

                if (trim($selector == '')) break;

                $num = 0;

                $selector = preg_replace('/'.$s.'\w+/','',$selector,-1,$num);

                $precedence += ($value * $num);

                $value /= 10;

            }

            $selectorcache[$selectorkey] = $precedence;

        }



        return $selectorcache[$selectorkey];

    }



	// right now we support all CSS 1 selectors and /some/ CSS2/3 selectors.

	// http://plasmasturm.org/log/444/

	private function translateCSStoXpath($css_selector) {



        $css_selector = trim($css_selector);

        static $xpathcache = array();

        $xpathkey = md5($css_selector);

        if (!isset($xpathcache[$xpathkey])) {

            // returns an Xpath selector

            $search = array(

                               '/\s+>\s+/', // Matches any F element that is a child of an element E.

                               '/(\w+)\s+\+\s+(\w+)/', // Matches any F element that is a child of an element E.

                               '/\s+/', // Matches any F element that is a descendant of an E element.

                               '/(\w)\[(\w+)\]/', // Matches element with attribute

                               '/(\w)\[(\w+)\=[\'"]?(\w+)[\'"]?\]/', // Matches element with EXACT attribute

                               '/(\w+)?\#([\w\-]+)/e', // Matches id attributes

                               '/(\w+|\*)?((\.[\w\-]+)+)/e', // Matches class attributes

            );

            $replace = array(

                               '/',

                               '\\1/following-sibling::*[1]/self::\\2',

                               '//',

                               '\\1[@\\2]',

                               '\\1[@\\2="\\3"]',

                               "(strlen('\\1') ? '\\1' : '*').'[@id=\"\\2\"]'",

                               "(strlen('\\1') ? '\\1' : '*').'[contains(concat(\" \",@class,\" \"),concat(\" \",\"'.implode('\",\" \"))][contains(concat(\" \",@class,\" \"),concat(\" \",\"',explode('.',substr('\\2',1))).'\",\" \"))]'",

            );

            $xpathcache[$xpathkey] = '//'.preg_replace($search,$replace,$css_selector);

        }

        return $xpathcache[$xpathkey];

	}



	private function cssStyleDefinitionToArray($style) {

	    $definitions = explode(';',$style);

	    $retArr = array();

	    foreach ($definitions as $def) {

            if (empty($def) || strpos($def, ':') === false) continue;

    	    list($key,$value) = explode(':',$def,2);

    	    if (empty($key) || strlen(trim($value)) === 0) continue;

    	    $retArr[trim($key)] = trim($value);

	    }

	    return $retArr;

	}



	private function fixCompatibility($text){

		$replace = array();

		$replace['#<br>#i'] = '<br />';

		return preg_replace(array_keys($replace),$replace,$text);

	}

}