<?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;
$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);
}
}