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piwigo_ynh/sources/include/emogrifier.class.php
2015-07-05 19:03:18 +02:00

682 lines
24 KiB
PHP

<?php
/**
* This class provides functions for converting CSS styles into inline style attributes in your HTML code.
*
* For more information, please see the README.md file.
*
* @author Cameron Brooks
* @author Jaime Prado
*/
class Emogrifier {
/**
* @var string
*/
const ENCODING = 'UTF-8';
/**
* @var integer
*/
const CACHE_KEY_CSS = 0;
/**
* @var integer
*/
const CACHE_KEY_SELECTOR = 1;
/**
* @var integer
*/
const CACHE_KEY_XPATH = 2;
/**
* for calculating nth-of-type and nth-child selectors
*
* @var integer
*/
const INDEX = 0;
/**
* for calculating nth-of-type and nth-child selectors
*
* @var integer
*/
const MULTIPLIER = 1;
/**
* @var string
*/
const ID_ATTRIBUTE_MATCHER = '/(\\w+)?\\#([\\w\\-]+)/';
/**
* @var string
*/
const CLASS_ATTRIBUTE_MATCHER = '/(\\w+|[\\*\\]])?((\\.[\\w\\-]+)+)/';
/**
* @var string
*/
private $html = '';
/**
* @var string
*/
private $css = '';
/**
* @var array<string>
*/
private $unprocessableHtmlTags = array('wbr');
/**
* @var array<array>
*/
private $caches = array(
self::CACHE_KEY_CSS => array(),
self::CACHE_KEY_SELECTOR => array(),
self::CACHE_KEY_XPATH => array(),
);
/**
* the visited nodes with the XPath paths as array keys
*
* @var array<\DOMNode>
*/
private $visitedNodes = array();
/**
* the styles to apply to the nodes with the XPath paths as array keys for the outer array and the attribute names/values
* as key/value pairs for the inner array
*
* @var array<array><string>
*/
private $styleAttributesForNodes = 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.
*
* @var boolean
*/
public $preserveEncoding = FALSE;
/**
* The constructor.
*
* @param string $html the HTML to emogrify, must be UTF-8-encoded
* @param string $css the CSS to merge, must be UTF-8-encoded
*/
public function __construct($html = '', $css = '') {
$this->setHtml($html);
$this->setCss($css);
}
/**
* The destructor.
*/
public function __destruct() {
$this->purgeVisitedNodes();
}
/**
* Sets the HTML to emogrify.
*
* @param string $html the HTML to emogrify, must be UTF-8-encoded
*
* @return void
*/
public function setHtml($html = '') {
$this->html = $html;
}
/**
* Sets the CSS to merge with the HTML.
*
* @param string $css the CSS to merge, must be UTF-8-encoded
*
* @return void
*/
public function setCss($css = '') {
$this->css = $css;
}
/**
* Clears all caches.
*
* @return void
*/
private function clearAllCaches() {
$this->clearCache(self::CACHE_KEY_CSS);
$this->clearCache(self::CACHE_KEY_SELECTOR);
$this->clearCache(self::CACHE_KEY_XPATH);
}
/**
* Clears a single cache by key.
*
* @param integer $key the cache key, must be CACHE_KEY_CSS, CACHE_KEY_SELECTOR or CACHE_KEY_XPATH
*
* @return void
*
* @throws \InvalidArgumentException
*/
private function clearCache($key) {
$allowedCacheKeys = array(self::CACHE_KEY_CSS, self::CACHE_KEY_SELECTOR, self::CACHE_KEY_XPATH);
if (!in_array($key, $allowedCacheKeys, TRUE)) {
throw new InvalidArgumentException('Invalid cache key: ' . $key, 1391822035);
}
$this->caches[$key] = array();
}
/**
* Purges the visited nodes.
*
* @return void
*/
private function purgeVisitedNodes() {
$this->visitedNodes = array();
$this->styleAttributesForNodes = array();
}
/**
* Marks a tag for removal.
*
* There are some HTML tags that DOMDocument cannot process, and it will throw an error if it encounters them.
* In particular, DOMDocument will complain if you try to use HTML5 tags in an XHTML document.
*
* Note: The tags will not be removed if they have any content.
*
* @param string $tagName the tag name, e.g., "p"
*
* @return void
*/
public function addUnprocessableHtmlTag($tagName) {
$this->unprocessableHtmlTags[] = $tagName;
}
/**
* Drops a tag from the removal list.
*
* @param string $tagName the tag name, e.g., "p"
*
* @return void
*/
public function removeUnprocessableHtmlTag($tagName) {
$key = array_search($tagName, $this->unprocessableHtmlTags, TRUE);
if ($key !== FALSE) {
unset($this->unprocessableHtmlTags[$key]);
}
}
/**
* Applies the CSS you submit to the HTML you submit.
*
* This method places the CSS inline.
*
* @return string
*
* @throws \BadMethodCallException
*/
public function emogrify() {
if ($this->html === '') {
throw new BadMethodCallException('Please set some HTML first before calling emogrify.', 1390393096);
}
$xmlDocument = $this->createXmlDocument();
$xpath = new DOMXPath($xmlDocument);
$this->clearAllCaches();
// 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
$this->purgeVisitedNodes();
$nodesWithStyleAttributes = $xpath->query('//*[@style]');
if ($nodesWithStyleAttributes !== FALSE) {
$callback = create_function('$m', 'return strtolower($m[0]);');
/** @var $nodeWithStyleAttribute \DOMNode */
foreach ($nodesWithStyleAttributes as $node) {
$normalizedOriginalStyle = preg_replace_callback(
'/[A-z\\-]+(?=\\:)/S',
$callback,
$node->getAttribute('style')
);
// in order to not overwrite existing style attributes in the HTML, we have to save the original HTML styles
$nodePath = $node->getNodePath();
if (!isset($this->styleAttributesForNodes[$nodePath])) {
$this->styleAttributesForNodes[$nodePath] = $this->parseCssDeclarationBlock($normalizedOriginalStyle);
$this->visitedNodes[$nodePath] = $node;
}
$node->setAttribute('style', $normalizedOriginalStyle);
}
}
// 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;
$styleNodes = $xpath->query('//style');
if ($styleNodes !== FALSE) {
/** @var $styleNode \DOMNode */
foreach ($styleNodes as $styleNode) {
// append the css
$css .= "\n\n" . $styleNode->nodeValue;
// remove the <style> node
$styleNode->parentNode->removeChild($styleNode);
}
}
// filter the CSS
$search = array(
// get rid of css comment code
'/\\/\\*.*\\*\\//sU',
// strip out any import directives
'/^\\s*@import\\s[^;]+;/misU',
// strip any empty media enclosures
'/^\\s*@media\\s[^{]+{\\s*}/misU',
// strip out all media rules that are not 'screen' or 'all' (these don't apply to email)
'/^\\s*@media\\s+((aural|braille|embossed|handheld|print|projection|speech|tty|tv)\\s*,*\\s*)+{.*}\\s*}/misU',
// get rid of remaining media type rules
'/^\\s*@media\\s[^{]+{(.*})\\s*}/misU',
);
$replace = array(
'',
'',
'',
'',
'\\1',
);
$css = preg_replace($search, $replace, $css);
$cssKey = md5($css);
if (!isset($this->caches[self::CACHE_KEY_CSS][$cssKey])) {
// process the CSS file for selectors and definitions
preg_match_all('/(?:^|[^{}])\\s*([^{]+){([^}]*)}/mis', $css, $matches, PREG_SET_ORDER);
$allSelectors = array();
foreach ($matches as $key => $selectorString) {
// if there is a blank definition, skip
if (!strlen(trim($selectorString[2]))) {
continue;
}
// else split by commas and duplicate attributes so we can sort by selector precedence
$selectors = explode(',', $selectorString[1]);
foreach ($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;
}
$allSelectors[] = array('selector' => trim($selector),
'attributes' => trim($selectorString[2]),
// keep track of where it appears in the file, since order is important
'line' => $key,
);
}
}
// now sort the selectors by precedence
usort($allSelectors, array($this,'sortBySelectorPrecedence'));
$this->caches[self::CACHE_KEY_CSS][$cssKey] = $allSelectors;
}
foreach ($this->caches[self::CACHE_KEY_CSS][$cssKey] as $value) {
// query the body for the xpath selector
$nodesMatchingCssSelectors = $xpath->query($this->translateCssToXpath(trim($value['selector'])));
/** @var $node \DOMNode */
foreach ($nodesMatchingCssSelectors 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
$oldStyleDeclarations = $this->parseCssDeclarationBlock($node->getAttribute('style'));
$newStyleDeclarations = $this->parseCssDeclarationBlock($value['attributes']);
// new styles overwrite the old styles (not technically accurate, but close enough)
$combinedArray = array_merge($oldStyleDeclarations, $newStyleDeclarations);
$style = '';
foreach ($combinedArray as $attributeName => $attributeValue) {
$style .= (strtolower($attributeName) . ':' . $attributeValue . ';');
}
} else {
// otherwise create a new style
$style = trim($value['attributes']);
}
$node->setAttribute('style', $style);
}
}
// now iterate through the nodes that contained inline styles in the original HTML
foreach ($this->styleAttributesForNodes as $nodePath => $styleAttributesForNode) {
$node = $this->visitedNodes[$nodePath];
$currentStyleAttributes = $this->parseCssDeclarationBlock($node->getAttribute('style'));
$combinedArray = array_merge($currentStyleAttributes, $styleAttributesForNode);
$style = '';
foreach ($combinedArray as $attributeName => $attributeValue) {
$style .= (strtolower($attributeName) . ':' . $attributeValue . ';');
}
$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.
$nodesWithStyleDisplayNone = $xpath->query('//*[contains(translate(translate(@style," ",""),"NOE","noe"),"display:none")]');
// The checks on parentNode and is_callable below ensure that if we've deleted the parent node,
// we don't try to call removeChild on a nonexistent child node
if ($nodesWithStyleDisplayNone->length > 0) {
/** @var $node \DOMNode */
foreach ($nodesWithStyleDisplayNone as $node) {
if ($node->parentNode && is_callable(array($node->parentNode,'removeChild'))) {
$node->parentNode->removeChild($node);
}
}
}
if ($this->preserveEncoding) {
return mb_convert_encoding($xmlDocument->saveHTML(), self::ENCODING, 'HTML-ENTITIES');
} else {
return $xmlDocument->saveHTML();
}
}
/**
* Creates a DOMDocument instance with the current HTML.
*
* @return \DOMDocument
*/
private function createXmlDocument() {
$xmlDocument = new DOMDocument;
$xmlDocument->encoding = self::ENCODING;
$xmlDocument->strictErrorChecking = FALSE;
$xmlDocument->formatOutput = TRUE;
$libxmlState = libxml_use_internal_errors(TRUE);
$xmlDocument->loadHTML($this->getUnifiedHtml());
libxml_clear_errors();
libxml_use_internal_errors($libxmlState);
$xmlDocument->normalizeDocument();
return $xmlDocument;
}
/**
* Returns the HTML with the non-ASCII characters converts into HTML entities and the unprocessable HTML tags removed.
*
* @return string the unified HTML
*
* @throws \BadMethodCallException
*/
private function getUnifiedHtml() {
if (!empty($this->unprocessableHtmlTags)) {
$unprocessableHtmlTags = implode('|', $this->unprocessableHtmlTags);
$bodyWithoutUnprocessableTags = preg_replace('/<\\/?(' . $unprocessableHtmlTags . ')[^>]*>/i', '', $this->html);
} else {
$bodyWithoutUnprocessableTags = $this->html;
}
return mb_convert_encoding($bodyWithoutUnprocessableTags, 'HTML-ENTITIES', self::ENCODING);
}
/**
* @param array $a
* @param array $b
*
* @return integer
*/
private function sortBySelectorPrecedence(array $a, array $b) {
$precedenceA = $this->getCssSelectorPrecedence($a['selector']);
$precedenceB = $this->getCssSelectorPrecedence($b['selector']);
// We want these sorted in ascending order so selectors with lesser precedence get processed first and
// selectors with greater precedence get sorted last.
// The parenthesis around the -1 are necessary to avoid a PHP_CodeSniffer warning about missing spaces around
// arithmetic operators.
// @see http://forge.typo3.org/issues/55605
$precedenceForEquals = ($a['line'] < $b['line'] ? (-1) : 1);
$precedenceForNotEquals = ($precedenceA < $precedenceB ? (-1) : 1);
return ($precedenceA === $precedenceB) ? $precedenceForEquals : $precedenceForNotEquals;
}
/**
* @param string $selector
*
* @return integer
*/
private function getCssSelectorPrecedence($selector) {
$selectorKey = md5($selector);
if (!isset($this->caches[self::CACHE_KEY_SELECTOR][$selectorKey])) {
$precedence = 0;
$value = 100;
// ids: worth 100, classes: worth 10, elements: worth 1
$search = array('\\#','\\.','');
foreach ($search as $s) {
if (trim($selector == '')) {
break;
}
$number = 0;
$selector = preg_replace('/' . $s . '\\w+/', '', $selector, -1, $number);
$precedence += ($value * $number);
$value /= 10;
}
$this->caches[self::CACHE_KEY_SELECTOR][$selectorKey] = $precedence;
}
return $this->caches[self::CACHE_KEY_SELECTOR][$selectorKey];
}
/**
* Right now, we support all CSS 1 selectors and most CSS2/3 selectors.
*
* @see http://plasmasturm.org/log/444/
*
* @param string $cssSelector
*
* @return string
*/
private function translateCssToXpath($cssSelector) {
$cssSelector = trim($cssSelector);
$xpathKey = md5($cssSelector);
if (!isset($this->caches[self::CACHE_KEY_XPATH][$xpathKey])) {
// returns an Xpath selector
$search = array(
// Matches any element that is a child of parent.
'/\\s+>\\s+/',
// Matches any element that is an adjacent sibling.
'/\\s+\\+\\s+/',
// Matches any element that is a descendant of an parent element element.
'/\\s+/',
// first-child pseudo-selector
'/([^\\/]+):first-child/i',
// last-child pseudo-selector
'/([^\\/]+):last-child/i',
// Matches element with attribute
'/(\\w)\\[(\\w+)\\]/',
// Matches element with EXACT attribute
'/(\\w)\\[(\\w+)\\=[\'"]?(\\w+)[\'"]?\\]/',
);
$replace = array(
'/',
'/following-sibling::*[1]/self::',
'//',
'*[1]/self::\\1',
'*[last()]/self::\\1',
'\\1[@\\2]',
'\\1[@\\2="\\3"]',
);
$cssSelector = '//' . preg_replace($search, $replace, $cssSelector);
$cssSelector = preg_replace_callback(self::ID_ATTRIBUTE_MATCHER, array($this, 'matchIdAttributes'), $cssSelector);
$cssSelector = preg_replace_callback(self::CLASS_ATTRIBUTE_MATCHER, array($this, 'matchClassAttributes'), $cssSelector);
// Advanced selectors are going to require a bit more advanced emogrification.
// When we required PHP 5.3, we could do this with closures.
$cssSelector = preg_replace_callback(
'/([^\\/]+):nth-child\\(\s*(odd|even|[+\-]?\\d|[+\\-]?\\d?n(\\s*[+\\-]\\s*\\d)?)\\s*\\)/i',
array($this, 'translateNthChild'), $cssSelector
);
$cssSelector = preg_replace_callback(
'/([^\\/]+):nth-of-type\\(\s*(odd|even|[+\-]?\\d|[+\\-]?\\d?n(\\s*[+\\-]\\s*\\d)?)\\s*\\)/i',
array($this, 'translateNthOfType'), $cssSelector
);
$this->caches[self::CACHE_KEY_SELECTOR][$xpathKey] = $cssSelector;
}
return $this->caches[self::CACHE_KEY_SELECTOR][$xpathKey];
}
/**
* @param array $match
*
* @return string
*/
private function matchIdAttributes(array $match) {
return (strlen($match[1]) ? $match[1] : '*') . '[@id="' . $match[2] . '"]';
}
/**
* @param array $match
*
* @return string
*/
private function matchClassAttributes(array $match) {
return (strlen($match[1]) ? $match[1] : '*') . '[contains(concat(" ",@class," "),concat(" ","' .
implode(
'"," "))][contains(concat(" ",@class," "),concat(" ","',
explode('.', substr($match[2], 1))
) . '"," "))]';
}
/**
* @param array $match
*
* @return string
*/
private function translateNthChild(array $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]);
}
}
/**
* @param array $match
*
* @return string
*/
private function translateNthOfType(array $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]);
}
}
/**
* @param array $match
*
* @return array
*/
private function parseNth(array $match) {
if (in_array(strtolower($match[2]), array('even','odd'))) {
$index = strtolower($match[2]) == 'even' ? 0 : 1;
return array(self::MULTIPLIER => 2, self::INDEX => $index);
} elseif (stripos($match[2], 'n') === FALSE) {
// if there is a multiplier
$index = intval(str_replace(' ', '', $match[2]));
return array(self::INDEX => $index);
} else {
if (isset($match[3])) {
$multipleTerm = str_replace($match[3], '', $match[2]);
$index = intval(str_replace(' ', '', $match[3]));
} else {
$multipleTerm = $match[2];
$index = 0;
}
$multiplier = str_ireplace('n', '', $multipleTerm);
if (!strlen($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);
}
}
/**
* Parses a CSS declaration block into property name/value pairs.
*
* Example:
*
* The declaration block
*
* "color: #000; font-weight: bold;"
*
* will be parsed into the following array:
*
* "color" => "#000"
* "font-weight" => "bold"
*
* @param string $cssDeclarationBlock the CSS declaration block without the curly braces, may be empty
*
* @return array the CSS declarations with the property names as array keys and the property values as array values
*/
private function parseCssDeclarationBlock($cssDeclarationBlock) {
$properties = array();
$declarations = explode(';', $cssDeclarationBlock);
foreach ($declarations as $declaration) {
$matches = array();
if (!preg_match('/ *([a-z\-]+) *: *([^;]+) */', $declaration, $matches)) {
continue;
}
$propertyName = $matches[1];
$propertyValue = $matches[2];
$properties[$propertyName] = $propertyValue;
}
return $properties;
}
}