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Diffstat (limited to 'include/emogrifier.class.php')
| -rw-r--r-- | include/emogrifier.class.php | 404 |
1 files changed, 404 insertions, 0 deletions
diff --git a/include/emogrifier.class.php b/include/emogrifier.class.php new file mode 100644 index 000000000..ef2c49730 --- /dev/null +++ b/include/emogrifier.class.php @@ -0,0 +1,404 @@ +<?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 + 2011-04-08 Fixed errors in CSS->XPath conversion for adjacent sibling selectors and id/class combinations... Thanks Bob V.! + 2011-06-08 Fixed an error where CSS @media types weren't being parsed correctly... Thanks Will W.! + 2011-08-03 Fixed an error where an empty selector at the beginning of the CSS would cause a parse error on the next selector... Thanks Alexei T.! + 2011-10-13 Fully fixed a bug introduced in 2011-06-08 where selectors at the beginning of the CSS would be parsed incorrectly... Thanks Thomas A.! + 2011-10-26 Added an option to allow you to output emogrified code without extended characters being turned into HTML entities. + Moved static references to class attributes so they can be manipulated. + Added the ability to clear out the (formerly) static cache when CSS is reloaded. + 2011-12-22 Fixed a bug that was overwriting existing inline styles from the original HTML... Thanks Sagi L.! + 2012-01-31 Fixed a bug that was introduced with the 2011-12-22 revision... Thanks Sagi L. and M. Bąkowski! + Added extraction of <style> blocks within the HTML due to popular demand. + Added several new pseudo-selectors (first-child, last-child, nth-child, and nth-of-type). + 2012-02-07 Fixed some recent code introductions to use class constants rather than global constants. + Fixed some recent code introductions to make it cleaner to read. + 2012-05-01 Made removal of invisible nodes operate in a case-insensitive manner... Thanks Juha P.! + 2013-10-10 Add preserveStyleTag option +*/ + +define('CACHE_CSS', 0); +define('CACHE_SELECTOR', 1); +define('CACHE_XPATH', 2); + +class Emogrifier { + + // for calculating nth-of-type and nth-child selectors + const INDEX = 0; + const MULTIPLIER = 1; + + private $html = ''; + private $css = ''; + private $unprocessableHTMLTags = array('wbr'); + private $caches = array(); + + // this attribute applies to the case where you want to preserve your original text encoding. + // by default, emogrifier translates your text into HTML entities for two reasons: + // 1. because of client incompatibilities, it is better practice to send out HTML entities rather than unicode over email + // 2. it translates any illegal XML characters that DOMDocument cannot work with + // if you would like to preserve your original encoding, set this attribute to true. + public $preserveEncoding = false; + + // by default, emogrifier removes <style> tags, set preserveStyleTag to true to keep them + public $preserveStyleTag = false; + + public function __construct($html = '', $css = '') { + $this->html = $html; + $this->css = $css; + $this->clearCache(); + } + + public function setHTML($html = '') { $this->html = $html; } + public function setCSS($css = '') { + $this->css = $css; + $this->clearCache(CACHE_CSS); + } + + public function clearCache($key = null) { + if (!is_null($key)) { + if (isset($this->caches[$key])) $this->caches[$key] = array(); + } else { + $this->caches = array( + CACHE_CSS => array(), + CACHE_SELECTOR => array(), + CACHE_XPATH => array(), + ); + } + } + + // there are some HTML tags that DOMDocument cannot process, and will throw an error if it encounters them. + // in particular, DOMDocument will complain if you try to use HTML5 tags in an XHTML document. + // these functions allow you to add/remove them if necessary. + // it only strips them from the code (does not remove actual nodes). + public function addUnprocessableHTMLTag($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 = $this->html; + + // remove any unprocessable HTML tags (tags that DOMDocument cannot parse; this includes wbr and many new HTML5 tags) + if (count($this->unprocessableHTMLTags)) { + $unprocessableHTMLTags = implode('|',$this->unprocessableHTMLTags); + $body = preg_replace("/<\/?($unprocessableHTMLTags)[^>]*>/i",'',$body); + } + + $encoding = mb_detect_encoding($body); + $body = mb_convert_encoding($body, 'HTML-ENTITIES', $encoding); + + $xmldoc = new DOMDocument; + $xmldoc->encoding = $encoding; + $xmldoc->strictErrorChecking = false; + $xmldoc->formatOutput = true; + $xmldoc->loadHTML($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. + // also store a reference of nodes with existing inline styles so we don't overwrite them + $vistedNodes = $vistedNodeRef = array(); + $nodes = @$xpath->query('//*[@style]'); + foreach ($nodes as $node) { + $normalizedOrigStyle = preg_replace('/[A-z\-]+(?=\:)/Se',"strtolower('\\0')", $node->getAttribute('style')); + + // in order to not overwrite existing style attributes in the HTML, we have to save the original HTML styles + $nodeKey = md5($node->getNodePath()); + if (!isset($vistedNodeRef[$nodeKey])) { + $vistedNodeRef[$nodeKey] = $this->cssStyleDefinitionToArray($normalizedOrigStyle); + $vistedNodes[$nodeKey] = $node; + } + + $node->setAttribute('style', $normalizedOrigStyle); + } + + // grab any existing style blocks from the html and append them to the existing CSS + // (these blocks should be appended so as to have precedence over conflicting styles in the existing CSS) + $css = $this->css; + $nodes = @$xpath->query('//style'); + foreach ($nodes as $node) { + // append the css + $css .= "\n\n{$node->nodeValue}"; + // remove the <style> node + if (!$this->preserveStyleTag) { + $node->parentNode->removeChild($node); + } + } + + // filter the CSS + $search = array( + '/\/\*.*\*\//sU', // get rid of css comment code + '/^\s*@import\s[^;]+;/misU', // strip out any import directives + '/^\s*@media\s[^{]+{\s*}/misU', // strip any empty media enclosures + '/^\s*@media\s+((aural|braille|embossed|handheld|print|projection|speech|tty|tv)\s*,*\s*)+{.*}\s*}/misU', // strip out all media types that are not 'screen' or 'all' (these don't apply to email) + '/^\s*@media\s[^{]+{(.*})\s*}/misU', // get rid of remaining media type enclosures + ); + + $replace = array( + '', + '', + '', + '', + '\\1', + ); + + $css = preg_replace($search, $replace, $css); + + $csskey = md5($css); + if (!isset($this->caches[CACHE_CSS][$csskey])) { + + // process the CSS file for selectors and definitions + preg_match_all('/(^|[^{}])\s*([^{]+){([^}]*)}/mis', $css, $matches, PREG_SET_ORDER); + + $all_selectors = array(); + foreach ($matches as $key => $selectorString) { + // if there is a blank definition, skip + if (!strlen(trim($selectorString[3]))) continue; + + // else split by commas and duplicate attributes so we can sort by selector precedence + $selectors = explode(',',$selectorString[2]); + foreach ($selectors as $selector) { + + // don't process pseudo-elements and behavioral (dynamic) pseudo-classes; ONLY allow structural pseudo-classes + if (strpos($selector, ':') !== false && !preg_match('/:\S+\-(child|type)\(/i', $selector)) continue; + + $all_selectors[] = array('selector' => trim($selector), + 'attributes' => trim($selectorString[3]), + 'line' => $key, // keep track of where it appears in the file, since order is important + ); + } + } + + // now sort the selectors by precedence + usort($all_selectors, array($this,'sortBySelectorPrecedence')); + + $this->caches[CACHE_CSS][$csskey] = $all_selectors; + } + + foreach ($this->caches[CACHE_CSS][$csskey] as $value) { + + // query the body for the xpath selector + $nodes = $xpath->query($this->translateCSStoXpath(trim($value['selector']))); + + foreach($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', $style); + } + } + + // now iterate through the nodes that contained inline styles in the original HTML + foreach ($vistedNodeRef as $nodeKey => $origStyleArr) { + $node = $vistedNodes[$nodeKey]; + $currStyleArr = $this->cssStyleDefinitionToArray($node->getAttribute('style')); + + $combinedArr = array_merge($currStyleArr, $origStyleArr); + $style = ''; + foreach ($combinedArr as $k => $v) $style .= (strtolower($k) . ':' . $v . ';'); + + $node->setAttribute('style', $style); + } + + // This removes styles from your email that contain display:none. + // We need to look for display:none, but we need to do a case-insensitive search. Since DOMDocument only supports XPath 1.0, + // lower-case() isn't available to us. We've thus far only set attributes to lowercase, not attribute values. Consequently, we need + // to translate() the letters that would be in 'NONE' ("NOE") to lowercase. + $nodes = $xpath->query('//*[contains(translate(translate(@style," ",""),"NOE","noe"),"display:none")]'); + // The checks on parentNode and is_callable below ensure that if we've deleted the parent node, + // we don't try to call removeChild on a nonexistent child node + if ($nodes->length > 0) + foreach ($nodes as $node) + if ($node->parentNode && is_callable(array($node->parentNode,'removeChild'))) + $node->parentNode->removeChild($node); + + if ($this->preserveEncoding) { + return mb_convert_encoding($xmldoc->saveHTML(), $encoding, 'HTML-ENTITIES'); + } else { + return $xmldoc->saveHTML(); + } + } + + private function sortBySelectorPrecedence($a, $b) { + $precedenceA = $this->getCSSSelectorPrecedence($a['selector']); + $precedenceB = $this->getCSSSelectorPrecedence($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['line'] < $b['line'] ? -1 : 1) : ($precedenceA < $precedenceB ? -1 : 1); + } + + private function getCSSSelectorPrecedence($selector) { + $selectorkey = md5($selector); + if (!isset($this->caches[CACHE_SELECTOR][$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; + } + $this->caches[CACHE_SELECTOR][$selectorkey] = $precedence; + } + + return $this->caches[CACHE_SELECTOR][$selectorkey]; + } + + // right now we support all CSS 1 selectors and most CSS2/3 selectors. + // http://plasmasturm.org/log/444/ + private function translateCSStoXpath($css_selector) { + + $css_selector = trim($css_selector); + $xpathkey = md5($css_selector); + if (!isset($this->caches[CACHE_XPATH][$xpathkey])) { + // returns an Xpath selector + $search = array( + '/\s+>\s+/', // Matches any element that is a child of parent. + '/\s+\+\s+/', // Matches any element that is an adjacent sibling. + '/\s+/', // Matches any element that is a descendant of an parent element element. + '/([^\/]+):first-child/i', // first-child pseudo-selector + '/([^\/]+):last-child/i', // last-child pseudo-selector + '/(\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( + '/', + '/following-sibling::*[1]/self::', + '//', + '*[1]/self::\\1', + '*[last()]/self::\\1', + '\\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))).'\",\" \"))]'", + ); + + $css_selector = '//'.preg_replace($search, $replace, $css_selector); + + // advanced selectors are going to require a bit more advanced emogrification + // if we required PHP 5.3 we could do this with closures + $css_selector = preg_replace_callback('/([^\/]+):nth-child\(\s*(odd|even|[+\-]?\d|[+\-]?\d?n(\s*[+\-]\s*\d)?)\s*\)/i', array($this, 'translateNthChild'), $css_selector); + $css_selector = preg_replace_callback('/([^\/]+):nth-of-type\(\s*(odd|even|[+\-]?\d|[+\-]?\d?n(\s*[+\-]\s*\d)?)\s*\)/i', array($this, 'translateNthOfType'), $css_selector); + + $this->caches[CACHE_SELECTOR][$xpathkey] = $css_selector; + } + return $this->caches[CACHE_SELECTOR][$xpathkey]; + } + + private function translateNthChild($match) { + + $result = $this->parseNth($match); + + if (isset($result[self::MULTIPLIER])) { + if ($result[self::MULTIPLIER] < 0) { + $result[self::MULTIPLIER] = abs($result[self::MULTIPLIER]); + return sprintf("*[(last() - position()) mod %u = %u]/self::%s", $result[self::MULTIPLIER], $result[self::INDEX], $match[1]); + } else { + return sprintf("*[position() mod %u = %u]/self::%s", $result[self::MULTIPLIER], $result[self::INDEX], $match[1]); + } + } else { + return sprintf("*[%u]/self::%s", $result[self::INDEX], $match[1]); + } + } + + private function translateNthOfType($match) { + + $result = $this->parseNth($match); + + if (isset($result[self::MULTIPLIER])) { + if ($result[self::MULTIPLIER] < 0) { + $result[self::MULTIPLIER] = abs($result[self::MULTIPLIER]); + return sprintf("%s[(last() - position()) mod %u = %u]", $match[1], $result[self::MULTIPLIER], $result[self::INDEX]); + } else { + return sprintf("%s[position() mod %u = %u]", $match[1], $result[self::MULTIPLIER], $result[self::INDEX]); + } + } else { + return sprintf("%s[%u]", $match[1], $result[self::INDEX]); + } + } + + private function parseNth($match) { + + if (in_array(strtolower($match[2]), array('even','odd'))) { + $index = strtolower($match[2]) == 'even' ? 0 : 1; + return array(self::MULTIPLIER => 2, self::INDEX => $index); + // if there is a multiplier + } else if (stripos($match[2], 'n') === false) { + $index = intval(str_replace(' ', '', $match[2])); + return array(self::INDEX => $index); + } else { + + if (isset($match[3])) { + $multiple_term = str_replace($match[3], '', $match[2]); + $index = intval(str_replace(' ', '', $match[3])); + } else { + $multiple_term = $match[2]; + $index = 0; + } + + $multiplier = str_ireplace('n', '', $multiple_term); + + if (!strlen($multiplier)) $multiplier = 1; + elseif ($multiplier == 0) return array(self::INDEX => $index); + else $multiplier = intval($multiplier); + + while ($index < 0) $index += abs($multiplier); + + return array(self::MULTIPLIER => $multiplier, self::INDEX => $index); + } + } + + private function cssStyleDefinitionToArray($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; + } +}
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