woocommerce/includes/libraries/class-emogrifier.php

1557 lines
41 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.
*
* @version 1.2.0
*
* @author Cameron Brooks
* @author Jaime Prado
* @author Oliver Klee <typo3-coding@oliverklee.de>
* @author Roman Ožana <ozana@omdesign.cz>
* @author Sander Kruger <s.kruger@invessel.com>
*/
// @codingStandardsIgnoreFile
class Emogrifier
{
/**
* @var int
*/
const CACHE_KEY_CSS = 0;
/**
* @var int
*/
const CACHE_KEY_SELECTOR = 1;
/**
* @var int
*/
const CACHE_KEY_XPATH = 2;
/**
* @var int
*/
const CACHE_KEY_CSS_DECLARATIONS_BLOCK = 3;
/**
* @var int
*/
const CACHE_KEY_COMBINED_STYLES = 4;
/**
* for calculating nth-of-type and nth-child selectors
*
* @var int
*/
const INDEX = 0;
/**
* for calculating nth-of-type and nth-child selectors
*
* @var int
*/
const MULTIPLIER = 1;
/**
* @var string
*/
const ID_ATTRIBUTE_MATCHER = '/(\\w+)?\\#([\\w\\-]+)/';
/**
* @var string
*/
const CLASS_ATTRIBUTE_MATCHER = '/(\\w+|[\\*\\]])?((\\.[\\w\\-]+)+)/';
/**
* @var string
*/
const CONTENT_TYPE_META_TAG = '<meta http-equiv="Content-Type" content="text/html; charset=utf-8">';
/**
* @var string
*/
const DEFAULT_DOCUMENT_TYPE = '<!DOCTYPE html>';
/**
* @var string
*/
private $html = '';
/**
* @var string
*/
private $css = '';
/**
* @var bool[]
*/
private $excludedSelectors = array();
/**
* @var string[]
*/
private $unprocessableHtmlTags = array( 'wbr' );
/**
* @var bool[]
*/
private $allowedMediaTypes = array( 'all' => true, 'screen' => true, 'print' => true );
/**
* @var mixed[]
*/
private $caches = array(
self::CACHE_KEY_CSS => array(),
self::CACHE_KEY_SELECTOR => array(),
self::CACHE_KEY_XPATH => array(),
self::CACHE_KEY_CSS_DECLARATIONS_BLOCK => array(),
self::CACHE_KEY_COMBINED_STYLES => array(),
);
/**
* the visited nodes with the XPath paths as array keys
*
* @var \DOMElement[]
*/
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 string[][]
*/
private $styleAttributesForNodes = array();
/**
* Determines whether the "style" attributes of tags in the the HTML passed to this class should be preserved.
* If set to false, the value of the style attributes will be discarded.
*
* @var bool
*/
private $isInlineStyleAttributesParsingEnabled = true;
/**
* Determines whether the <style> blocks in the HTML passed to this class should be parsed.
*
* If set to true, the <style> blocks will be removed from the HTML and their contents will be applied to the HTML
* via inline styles.
*
* If set to false, the <style> blocks will be left as they are in the HTML.
*
* @var bool
*/
private $isStyleBlocksParsingEnabled = true;
/**
* Determines whether elements with the `display: none` property are
* removed from the DOM.
*
* @var bool
*/
private $shouldKeepInvisibleNodes = true;
/**
* @var string[]
*/
private $xPathRules = array(
// child
'/\\s*>\\s*/' => '/',
// adjacent sibling
'/\\s+\\+\\s+/' => '/following-sibling::*[1]/self::',
// descendant
'/\\s+(?=.*[^\\]]{1}$)/' => '//',
// :first-child
'/([^\\/]+):first-child/i' => '*[1]/self::\\1',
// :last-child
'/([^\\/]+):last-child/i' => '*[last()]/self::\\1',
// attribute only
'/^\\[(\\w+|\\w+\\=[\'"]?\\w+[\'"]?)\\]/' => '*[@\\1]',
// attribute
'/(\\w)\\[(\\w+)\\]/' => '\\1[@\\2]',
// exact attribute
'/(\\w)\\[(\\w+)\\=[\'"]?([\\w\\s]+)[\'"]?\\]/' => '\\1[@\\2="\\3"]',
// element attribute~=
'/([\\w\\*]+)\\[(\\w+)[\\s]*\\~\\=[\\s]*[\'"]?([\\w-_\\/]+)[\'"]?\\]/'
=> '\\1[contains(concat(" ", @\\2, " "), concat(" ", "\\3", " "))]',
// element attribute^=
'/([\\w\\*]+)\\[(\\w+)[\\s]*\\^\\=[\\s]*[\'"]?([\\w-_\\/]+)[\'"]?\\]/' => '\\1[starts-with(@\\2, "\\3")]',
// element attribute*=
'/([\\w\\*]+)\\[(\\w+)[\\s]*\\*\\=[\\s]*[\'"]?([\\w-_\\s\\/:;]+)[\'"]?\\]/' => '\\1[contains(@\\2, "\\3")]',
// element attribute$=
'/([\\w\\*]+)\\[(\\w+)[\\s]*\\$\\=[\\s]*[\'"]?([\\w-_\\s\\/]+)[\'"]?\\]/'
=> '\\1[substring(@\\2, string-length(@\\2) - string-length("\\3") + 1) = "\\3"]',
// element attribute|=
'/([\\w\\*]+)\\[(\\w+)[\\s]*\\|\\=[\\s]*[\'"]?([\\w-_\\s\\/]+)[\'"]?\\]/'
=> '\\1[@\\2="\\3" or starts-with(@\\2, concat("\\3", "-"))]',
);
/**
* Determines whether CSS styles that have an equivalent HTML attribute
* should be mapped and attached to those elements.
*
* @var bool
*/
private $shouldMapCssToHtml = false;
/**
* This multi-level array contains simple mappings of CSS properties to
* HTML attributes. If a mapping only applies to certain HTML nodes or
* only for certain values, the mapping is an object with a whitelist
* of nodes and values.
*
* @var mixed[][]
*/
private $cssToHtmlMap = array(
'background-color' => array(
'attribute' => 'bgcolor',
),
'text-align' => array(
'attribute' => 'align',
'nodes' => array('p', 'div', 'td'),
'values' => array('left', 'right', 'center', 'justify'),
),
'float' => array(
'attribute' => 'align',
'nodes' => array('table', 'img'),
'values' => array('left', 'right'),
),
'border-spacing' => array(
'attribute' => 'cellspacing',
'nodes' => array('table'),
),
);
public static $_media = '';
/**
* 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;
}
/**
* Applies $this->css to $this->html and returns the HTML with the CSS
* applied.
*
* This method places the CSS inline.
*
* @return string
*
* @throws \BadMethodCallException
*/
public function emogrify()
{
if ($this->html === '') {
throw new BadMethodCallException('Please set some HTML first before calling emogrify.', 1390393096);
}
self::$_media = ''; // reset.
$xmlDocument = $this->createXmlDocument();
$this->process($xmlDocument);
return $xmlDocument->saveHTML();
}
/**
* Applies $this->css to $this->html and returns only the HTML content
* within the <body> tag.
*
* This method places the CSS inline.
*
* @return string
*
* @throws \BadMethodCallException
*/
public function emogrifyBodyContent()
{
if ($this->html === '') {
throw new BadMethodCallException('Please set some HTML first before calling emogrify.', 1390393096);
}
$xmlDocument = $this->createXmlDocument();
$this->process($xmlDocument);
$innerDocument = new DOMDocument();
foreach ($xmlDocument->documentElement->getElementsByTagName('body')->item(0)->childNodes as $childNode) {
$innerDocument->appendChild($innerDocument->importNode($childNode, true));
}
return html_entity_decode($innerDocument->saveHTML());
}
/**
* Applies $this->css to $xmlDocument.
*
* This method places the CSS inline.
*
* @param \DOMDocument $xmlDocument
*
* @return void
*
* @throws \InvalidArgumentException
*/
protected function process(DOMDocument $xmlDocument)
{
$xPath = new DOMXPath($xmlDocument);
$this->clearAllCaches();
// Before be begin processing the CSS file, parse the document and normalize all existing CSS attributes.
// This 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.
$this->purgeVisitedNodes();
set_error_handler(array($this, 'handleXpathError'), E_WARNING);
$nodesWithStyleAttributes = $xPath->query('//*[@style]');
if ($nodesWithStyleAttributes !== false) {
/** @var \DOMElement $node */
foreach ($nodesWithStyleAttributes as $node) {
if ($this->isInlineStyleAttributesParsingEnabled) {
$this->normalizeStyleAttributes($node);
} else {
$node->removeAttribute('style');
}
}
}
// 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)
$allCss = $this->css;
if ($this->isStyleBlocksParsingEnabled) {
$allCss .= $this->getCssFromAllStyleNodes($xPath);
}
$cssParts = $this->splitCssAndMediaQuery($allCss);
$excludedNodes = $this->getNodesToExclude($xPath);
$cssRules = $this->parseCssRules($cssParts['css']);
foreach ($cssRules as $cssRule) {
// query the body for the xpath selector
$nodesMatchingCssSelectors = $xPath->query($this->translateCssToXpath($cssRule['selector']));
// ignore invalid selectors
if ($nodesMatchingCssSelectors === false) {
continue;
}
/** @var \DOMElement $node */
foreach ($nodesMatchingCssSelectors as $node) {
if (in_array($node, $excludedNodes, true)) {
continue;
}
// if it has a style attribute, get it, process it, and append (overwrite) new stuff
if ($node->hasAttribute('style')) {
// break it up into an associative array
$oldStyleDeclarations = $this->parseCssDeclarationsBlock($node->getAttribute('style'));
} else {
$oldStyleDeclarations = array();
}
$newStyleDeclarations = $this->parseCssDeclarationsBlock($cssRule['declarationsBlock']);
if ($this->shouldMapCssToHtml) {
$this->mapCssToHtmlAttributes($newStyleDeclarations, $node);
}
$node->setAttribute(
'style',
$this->generateStyleStringFromDeclarationsArrays($oldStyleDeclarations, $newStyleDeclarations)
);
}
}
restore_error_handler();
if ($this->isInlineStyleAttributesParsingEnabled) {
$this->fillStyleAttributesWithMergedStyles();
}
if ($this->shouldKeepInvisibleNodes) {
$this->removeInvisibleNodes($xPath);
}
$this->copyCssWithMediaToStyleNode($xmlDocument, $xPath, $cssParts['media']);
}
/**
* Applies $styles to $node.
*
* This method maps CSS styles to HTML attributes and adds those to the
* node.
*
* @param string[] $styles the new CSS styles taken from the global styles to be applied to this node
* @param \DOMNode $node node to apply styles to
*
* @return void
*/
private function mapCssToHtmlAttributes(array $styles, DOMNode $node)
{
foreach ($styles as $property => $value) {
// Strip !important indicator
$value = trim(str_replace('!important', '', $value));
$this->mapCssToHtmlAttribute($property, $value, $node);
}
}
/**
* Tries to apply the CSS style to $node as an attribute.
*
* This method maps a CSS rule to HTML attributes and adds those to the node.
*
* @param string $property the name of the CSS property to map
* @param string $value the value of the style rule to map
* @param \DOMNode $node node to apply styles to
*
* @return void
*/
private function mapCssToHtmlAttribute($property, $value, DOMNode $node)
{
if (!$this->mapSimpleCssProperty($property, $value, $node)) {
$this->mapComplexCssProperty($property, $value, $node);
}
}
/**
* Looks up the CSS property in the mapping table and maps it if it matches the conditions.
*
* @param string $property the name of the CSS property to map
* @param string $value the value of the style rule to map
* @param \DOMNode $node node to apply styles to
*
* @return bool true if the property cab be mapped using the simple mapping table
*/
private function mapSimpleCssProperty($property, $value, DOMNode $node)
{
if (!isset($this->cssToHtmlMap[$property])) {
return false;
}
$mapping = $this->cssToHtmlMap[$property];
$nodesMatch = !isset($mapping['nodes']) || in_array($node->nodeName, $mapping['nodes'], true);
$valuesMatch = !isset($mapping['values']) || in_array($value, $mapping['values'], true);
if (!$nodesMatch || !$valuesMatch) {
return false;
}
$node->setAttribute($mapping['attribute'], $value);
return true;
}
/**
* Maps CSS properties that need special transformation to an HTML attribute.
*
* @param string $property the name of the CSS property to map
* @param string $value the value of the style rule to map
* @param \DOMNode $node node to apply styles to
*
* @return void
*/
private function mapComplexCssProperty($property, $value, DOMNode $node)
{
$nodeName = $node->nodeName;
$isTable = $nodeName === 'table';
$isImage = $nodeName === 'img';
$isTableOrImage = $isTable || $isImage;
switch ($property) {
case 'background':
// Parse out the color, if any
$styles = explode(' ', $value);
$first = $styles[0];
if (!is_numeric(substr($first, 0, 1)) && substr($first, 0, 3) !== 'url') {
// This is not a position or image, assume it's a color
$node->setAttribute('bgcolor', $first);
}
break;
case 'width':
// intentional fall-through
case 'height':
// Only parse values in px and %, but not values like "auto".
if (preg_match('/^\d+(px|%)$/', $value)) {
// Remove 'px'. This regex only conserves numbers and %
$number = preg_replace('/[^0-9.%]/', '', $value);
$node->setAttribute($property, $number);
}
break;
case 'margin':
if ($isTableOrImage) {
$margins = $this->parseCssShorthandValue($value);
if ($margins['left'] === 'auto' && $margins['right'] === 'auto') {
$node->setAttribute('align', 'center');
}
}
break;
case 'border':
if ($isTableOrImage) {
if ($value === 'none' || $value === '0') {
$node->setAttribute('border', '0');
}
}
break;
default:
}
}
/**
* Parses a shorthand CSS value and splits it into individual values
*
* @param string $value a string of CSS value with 1, 2, 3 or 4 sizes
* For example: padding: 0 auto;
* '0 auto' is split into top: 0, left: auto, bottom: 0,
* right: auto.
*
* @return string[] an array of values for top, right, bottom and left (using these as associative array keys)
*/
private function parseCssShorthandValue($value)
{
$values = preg_split('/\\s+/', $value);
$css = array();
$css['top'] = $values[0];
$css['right'] = (count($values) > 1) ? $values[1] : $css['top'];
$css['bottom'] = (count($values) > 2) ? $values[2] : $css['top'];
$css['left'] = (count($values) > 3) ? $values[3] : $css['right'];
return $css;
}
/**
* Extracts and parses the individual rules from a CSS string.
*
* @param string $css a string of raw CSS code
*
* @return string[][] an array of string sub-arrays with the keys
* "selector" (the CSS selector(s), e.g., "*" or "h1"),
* "declarationsBLock" (the semicolon-separated CSS declarations for that selector(s),
* e.g., "color: red; height: 4px;"),
* and "line" (the line number e.g. 42)
*/
private function parseCssRules($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);
$cssRules = array();
/** @var string[] $cssRule */
foreach ($matches as $key => $cssRule) {
$cssDeclaration = trim($cssRule[2]);
if ($cssDeclaration === '') {
continue;
}
$selectors = explode(',', $cssRule[1]);
foreach ($selectors as $selector) {
// don't process pseudo-elements and behavioral (dynamic) pseudo-classes;
// only allow structural pseudo-classes
$hasPseudoElement = strpos($selector, '::') !== false;
$hasAnyPseudoClass = (bool) preg_match('/:[a-zA-Z]/', $selector);
$hasSupportedPseudoClass = (bool) preg_match('/:\\S+\\-(child|type\\()/i', $selector);
if ($hasPseudoElement || ($hasAnyPseudoClass && !$hasSupportedPseudoClass)) {
continue;
}
$cssRules[] = array(
'selector' => trim($selector),
'declarationsBlock' => $cssDeclaration,
// keep track of where it appears in the file, since order is important
'line' => $key,
);
}
}
usort($cssRules, array($this, 'sortBySelectorPrecedence'));
$this->caches[self::CACHE_KEY_CSS][$cssKey] = $cssRules;
}
return $this->caches[self::CACHE_KEY_CSS][$cssKey];
}
/**
* Disables the parsing of inline styles.
*
* @return void
*/
public function disableInlineStyleAttributesParsing()
{
$this->isInlineStyleAttributesParsingEnabled = false;
}
/**
* Disables the parsing of <style> blocks.
*
* @return void
*/
public function disableStyleBlocksParsing()
{
$this->isStyleBlocksParsingEnabled = false;
}
/**
* Disables the removal of elements with `display: none` properties.
*
* @return void
*/
public function disableInvisibleNodeRemoval()
{
$this->shouldKeepInvisibleNodes = false;
}
/**
* Enables the attachment/override of HTML attributes for which a
* corresponding CSS property has been set.
*
* @return void
*/
public function enableCssToHtmlMapping()
{
$this->shouldMapCssToHtml = true;
}
/**
* 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);
$this->clearCache(self::CACHE_KEY_CSS_DECLARATIONS_BLOCK);
$this->clearCache(self::CACHE_KEY_COMBINED_STYLES);
}
/**
* Clears a single cache by key.
*
* @param int $key the cache key, must be CACHE_KEY_CSS, CACHE_KEY_SELECTOR, CACHE_KEY_XPATH
* or CACHE_KEY_CSS_DECLARATION_BLOCK
*
* @return void
*
* @throws \InvalidArgumentException
*/
private function clearCache($key)
{
$allowedCacheKeys = array(
self::CACHE_KEY_CSS,
self::CACHE_KEY_SELECTOR,
self::CACHE_KEY_XPATH,
self::CACHE_KEY_CSS_DECLARATIONS_BLOCK,
self::CACHE_KEY_COMBINED_STYLES,
);
if (!in_array($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]);
}
}
/**
* Marks a media query type to keep.
*
* @param string $mediaName the media type name, e.g., "braille"
*
* @return void
*/
public function addAllowedMediaType($mediaName)
{
$this->allowedMediaTypes[$mediaName] = true;
}
/**
* Drops a media query type from the allowed list.
*
* @param string $mediaName the tag name, e.g., "braille"
*
* @return void
*/
public function removeAllowedMediaType($mediaName)
{
if (isset($this->allowedMediaTypes[$mediaName])) {
unset($this->allowedMediaTypes[$mediaName]);
}
}
/**
* Adds a selector to exclude nodes from emogrification.
*
* Any nodes that match the selector will not have their style altered.
*
* @param string $selector the selector to exclude, e.g., ".editor"
*
* @return void
*/
public function addExcludedSelector($selector)
{
$this->excludedSelectors[$selector] = true;
}
/**
* No longer excludes the nodes matching this selector from emogrification.
*
* @param string $selector the selector to no longer exclude, e.g., ".editor"
*
* @return void
*/
public function removeExcludedSelector($selector)
{
if (isset($this->excludedSelectors[$selector])) {
unset($this->excludedSelectors[$selector]);
}
}
/**
* 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.
*
* @param \DOMXPath $xPath
*
* @return void
*/
private function removeInvisibleNodes(DOMXPath $xPath)
{
$nodesWithStyleDisplayNone = $xPath->query(
'//*[contains(translate(translate(@style," ",""),"NOE","noe"),"display:none")]'
);
if ($nodesWithStyleDisplayNone->length === 0) {
return;
}
// 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
/** @var \DOMNode $node */
foreach ($nodesWithStyleDisplayNone as $node) {
if ($node->parentNode && is_callable(array($node->parentNode, 'removeChild'))) {
$node->parentNode->removeChild($node);
}
}
}
private function normalizeStyleAttributes_callback( $m ) {
return strtolower( $m[0] );
}
/**
* Normalizes the value of the "style" attribute and saves it.
*
* @param \DOMElement $node
*
* @return void
*/
private function normalizeStyleAttributes(DOMElement $node)
{
$normalizedOriginalStyle = preg_replace_callback(
'/[A-z\\-]+(?=\\:)/S',
array( $this, 'normalizeStyleAttributes_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] = $this->parseCssDeclarationsBlock($normalizedOriginalStyle);
$this->visitedNodes[$nodePath] = $node;
}
$node->setAttribute('style', $normalizedOriginalStyle);
}
/**
* Merges styles from styles attributes and style nodes and applies them to the attribute nodes
*
* @return void
*/
private function fillStyleAttributesWithMergedStyles()
{
foreach ($this->styleAttributesForNodes as $nodePath => $styleAttributesForNode) {
$node = $this->visitedNodes[$nodePath];
$currentStyleAttributes = $this->parseCssDeclarationsBlock($node->getAttribute('style'));
$node->setAttribute(
'style',
$this->generateStyleStringFromDeclarationsArrays(
$currentStyleAttributes,
$styleAttributesForNode
)
);
}
}
/**
* This method merges old or existing name/value array with new name/value array
* and then generates a string of the combined style suitable for placing inline.
* This becomes the single point for CSS string generation allowing for consistent
* CSS output no matter where the CSS originally came from.
*
* @param string[] $oldStyles
* @param string[] $newStyles
*
* @return string
*/
private function generateStyleStringFromDeclarationsArrays(array $oldStyles, array $newStyles)
{
$combinedStyles = array_merge($oldStyles, $newStyles);
$cacheKey = serialize($combinedStyles);
if (isset($this->caches[self::CACHE_KEY_COMBINED_STYLES][$cacheKey])) {
return $this->caches[self::CACHE_KEY_COMBINED_STYLES][$cacheKey];
}
foreach ($oldStyles as $attributeName => $attributeValue) {
if (!isset($newStyles[$attributeName])) {
continue;
}
$newAttributeValue = $newStyles[$attributeName];
if ($this->attributeValueIsImportant($attributeValue)
&& !$this->attributeValueIsImportant($newAttributeValue)
) {
$combinedStyles[$attributeName] = $attributeValue;
}
}
$style = '';
foreach ($combinedStyles as $attributeName => $attributeValue) {
$style .= strtolower(trim($attributeName)) . ': ' . trim($attributeValue) . '; ';
}
$trimmedStyle = rtrim($style);
$this->caches[self::CACHE_KEY_COMBINED_STYLES][$cacheKey] = $trimmedStyle;
return $trimmedStyle;
}
/**
* Checks whether $attributeValue is marked as !important.
*
* @param string $attributeValue
*
* @return bool
*/
private function attributeValueIsImportant($attributeValue)
{
return strtolower(substr(trim($attributeValue), -10)) === '!important';
}
/**
* Applies $css to $xmlDocument, limited to the media queries that actually apply to the document.
*
* @param \DOMDocument $xmlDocument the document to match against
* @param \DOMXPath $xPath
* @param string $css a string of CSS
*
* @return void
*/
private function copyCssWithMediaToStyleNode(DOMDocument $xmlDocument, DOMXPath $xPath, $css)
{
if ($css === '') {
return;
}
$mediaQueriesRelevantForDocument = array();
foreach ($this->extractMediaQueriesFromCss($css) as $mediaQuery) {
foreach ($this->parseCssRules($mediaQuery['css']) as $selector) {
if ($this->existsMatchForCssSelector($xPath, $selector['selector'])) {
$mediaQueriesRelevantForDocument[] = $mediaQuery['query'];
break;
}
}
}
$this->addStyleElementToDocument($xmlDocument, implode($mediaQueriesRelevantForDocument));
}
/**
* Extracts the media queries from $css while skipping empty media queries.
*
* @param string $css
*
* @return string[][] numeric array with string sub-arrays with the keys "css" and "query"
*/
private function extractMediaQueriesFromCss($css)
{
preg_match_all('/@media\\b[^{]*({((?:[^{}]+|(?1))*)})/', $css, $rawMediaQueries, PREG_SET_ORDER);
$parsedQueries = array();
foreach ($rawMediaQueries as $mediaQuery) {
if ($mediaQuery[2] !== '') {
$parsedQueries[] = array(
'css' => $mediaQuery[2],
'query' => $mediaQuery[0],
);
}
}
return $parsedQueries;
}
/**
* Checks whether there is at least one matching element for $cssSelector.
*
* @param \DOMXPath $xPath
* @param string $cssSelector
*
* @return bool
*/
private function existsMatchForCssSelector(DOMXPath $xPath, $cssSelector)
{
$nodesMatchingSelector = $xPath->query($this->translateCssToXpath($cssSelector));
return $nodesMatchingSelector !== false && $nodesMatchingSelector->length !== 0;
}
/**
* Returns CSS content.
*
* @param \DOMXPath $xPath
*
* @return string
*/
private function getCssFromAllStyleNodes(DOMXPath $xPath)
{
$styleNodes = $xPath->query('//style');
if ($styleNodes === false) {
return '';
}
$css = '';
/** @var \DOMNode $styleNode */
foreach ($styleNodes as $styleNode) {
$css .= "\n\n" . $styleNode->nodeValue;
$styleNode->parentNode->removeChild($styleNode);
}
return $css;
}
/**
* Adds a style element with $css to $document.
*
* This method is protected to allow overriding.
*
* @see https://github.com/jjriv/emogrifier/issues/103
*
* @param \DOMDocument $document
* @param string $css
*
* @return void
*/
protected function addStyleElementToDocument(DOMDocument $document, $css)
{
$styleElement = $document->createElement('style', $css);
$styleAttribute = $document->createAttribute('type');
$styleAttribute->value = 'text/css';
$styleElement->appendChild($styleAttribute);
$head = $this->getOrCreateHeadElement($document);
$head->appendChild($styleElement);
}
/**
* Returns the existing or creates a new head element in $document.
*
* @param \DOMDocument $document
*
* @return \DOMNode the head element
*/
private function getOrCreateHeadElement(DOMDocument $document)
{
$head = $document->getElementsByTagName('head')->item(0);
if ($head === null) {
$head = $document->createElement('head');
$html = $document->getElementsByTagName('html')->item(0);
$html->insertBefore($head, $document->getElementsByTagName('body')->item(0));
}
return $head;
}
/**
* Splits input CSS code to an array where:
*
* - key "css" will be contains clean CSS code
* - key "media" will be contains all valuable media queries
*
* Example:
*
* The CSS code
*
* "@import "file.css"; h1 { color:red; } @media { h1 {}} @media tv { h1 {}}"
*
* will be parsed into the following array:
*
* "css" => "h1 { color:red; }"
* "media" => "@media { h1 {}}"
*
* @param string $css
*
* @return string[]
*/
private function splitCssAndMediaQuery($css)
{
$cssWithoutComments = preg_replace('/\\/\\*.*\\*\\//sU', '', $css);
$mediaTypesExpression = '';
if (!empty($this->allowedMediaTypes)) {
$mediaTypesExpression = '|' . implode('|', array_keys($this->allowedMediaTypes));
}
$media = '';
$cssForAllowedMediaTypes = preg_replace_callback(
'#@media\\s+(?:only\\s)?(?:[\\s{\\(]' . $mediaTypesExpression . ')\\s?[^{]+{.*}\\s*}\\s*#misU',
array( $this, '_media_concat' ),
$cssWithoutComments
);
// filter the CSS
$search = array(
'import directives' => '/^\\s*@import\\s[^;]+;/misU',
'remaining media enclosures' => '/^\\s*@media\\s[^{]+{(.*)}\\s*}\\s/misU',
);
$cleanedCss = preg_replace($search, '', $cssForAllowedMediaTypes);
return array('css' => $cleanedCss, 'media' => self::$_media);
}
private function _media_concat( $matches ) {
self::$_media .= $matches[0];
}
/**
* Creates a DOMDocument instance with the current HTML.
*
* @return \DOMDocument
*/
private function createXmlDocument()
{
$xmlDocument = new DOMDocument;
$xmlDocument->encoding = 'UTF-8';
$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 unprocessable HTML tags removed and
* with added document type and Content-Type meta tag if needed.
*
* @return string the unified HTML
*
* @throws \BadMethodCallException
*/
private function getUnifiedHtml()
{
$htmlWithoutUnprocessableTags = $this->removeUnprocessableTags($this->html);
$htmlWithDocumentType = $this->ensureDocumentType($htmlWithoutUnprocessableTags);
return $this->addContentTypeMetaTag($htmlWithDocumentType);
}
/**
* Removes the unprocessable tags from $html (if this feature is enabled).
*
* @param string $html
*
* @return string the reworked HTML with the unprocessable tags removed
*/
private function removeUnprocessableTags($html)
{
if (empty($this->unprocessableHtmlTags)) {
return $html;
}
$unprocessableHtmlTags = implode('|', $this->unprocessableHtmlTags);
return preg_replace(
'/<\\/?(' . $unprocessableHtmlTags . ')[^>]*>/i',
'',
$html
);
}
/**
* Makes sure that the passed HTML has a document type.
*
* @param string $html
*
* @return string HTML with document type
*/
private function ensureDocumentType($html)
{
$hasDocumentType = stripos($html, '<!DOCTYPE') !== false;
if ($hasDocumentType) {
return $html;
}
return self::DEFAULT_DOCUMENT_TYPE . $html;
}
/**
* Adds a Content-Type meta tag for the charset.
*
* @param string $html
*
* @return string the HTML with the meta tag added
*/
private function addContentTypeMetaTag($html)
{
$hasContentTypeMetaTag = stristr($html, 'Content-Type') !== false;
if ($hasContentTypeMetaTag) {
return $html;
}
// We are trying to insert the meta tag to the right spot in the DOM.
// If we just prepended it to the HTML, we would lose attributes set to the HTML tag.
$hasHeadTag = stripos($html, '<head') !== false;
$hasHtmlTag = stripos($html, '<html') !== false;
if ($hasHeadTag) {
$reworkedHtml = preg_replace('/<head(.*?)>/i', '<head$1>' . self::CONTENT_TYPE_META_TAG, $html);
} elseif ($hasHtmlTag) {
$reworkedHtml = preg_replace(
'/<html(.*?)>/i',
'<html$1><head>' . self::CONTENT_TYPE_META_TAG . '</head>',
$html
);
} else {
$reworkedHtml = self::CONTENT_TYPE_META_TAG . $html;
}
return $reworkedHtml;
}
/**
* @param string[] $a
* @param string[] $b
*
* @return int
*/
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.
$precedenceForEquals = ($a['line'] < $b['line'] ? -1 : 1);
$precedenceForNotEquals = ($precedenceA < $precedenceB ? -1 : 1);
return ($precedenceA === $precedenceB) ? $precedenceForEquals : $precedenceForNotEquals;
}
/**
* @param string $selector
*
* @return int
*/
private function getCssSelectorPrecedence($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];
}
private function translateCssToXpath_callback( $matches ) {
return strtolower($matches[0]);
}
/**
* Maps a CSS selector to an XPath query string.
*
* @see http://plasmasturm.org/log/444/
*
* @param string $cssSelector a CSS selector
*
* @return string the corresponding XPath selector
*/
private function translateCssToXpath($cssSelector)
{
$paddedSelector = ' ' . $cssSelector . ' ';
$lowercasePaddedSelector = preg_replace_callback(
'/\\s+\\w+\\s+/',
array( $this, 'translateCssToXpath_callback' ),
$paddedSelector
);
$trimmedLowercaseSelector = trim($lowercasePaddedSelector);
$xPathKey = md5($trimmedLowercaseSelector);
if (!isset($this->caches[self::CACHE_KEY_XPATH][$xPathKey])) {
$roughXpath = '//' . preg_replace(
array_keys($this->xPathRules),
$this->xPathRules,
$trimmedLowercaseSelector
);
$xPathWithIdAttributeMatchers = preg_replace_callback(
self::ID_ATTRIBUTE_MATCHER,
array($this, 'matchIdAttributes'),
$roughXpath
);
$xPathWithIdAttributeAndClassMatchers = preg_replace_callback(
self::CLASS_ATTRIBUTE_MATCHER,
array($this, 'matchClassAttributes'),
$xPathWithIdAttributeMatchers
);
// Advanced selectors are going to require a bit more advanced emogrification.
// When we required PHP 5.3, we could do this with closures.
$xPathWithIdAttributeAndClassMatchers = preg_replace_callback(
'/([^\\/]+):nth-child\\(\\s*(odd|even|[+\\-]?\\d|[+\\-]?\\d?n(\\s*[+\\-]\\s*\\d)?)\\s*\\)/i',
array($this, 'translateNthChild'),
$xPathWithIdAttributeAndClassMatchers
);
$finalXpath = preg_replace_callback(
'/([^\\/]+):nth-of-type\\(\s*(odd|even|[+\\-]?\\d|[+\\-]?\\d?n(\\s*[+\\-]\\s*\\d)?)\\s*\\)/i',
array($this, 'translateNthOfType'),
$xPathWithIdAttributeAndClassMatchers
);
$this->caches[self::CACHE_KEY_SELECTOR][$xPathKey] = $finalXpath;
}
return $this->caches[self::CACHE_KEY_SELECTOR][$xPathKey];
}
/**
* @param string[] $match
*
* @return string
*/
private function matchIdAttributes(array $match)
{
return ($match[1] !== '' ? $match[1] : '*') . '[@id="' . $match[2] . '"]';
}
/**
* @param string[] $match
*
* @return string
*/
private function matchClassAttributes(array $match)
{
return ($match[1] !== '' ? $match[1] : '*') . '[contains(concat(" ",@class," "),concat(" ","' .
implode(
'"," "))][contains(concat(" ",@class," "),concat(" ","',
explode('.', substr($match[2], 1))
) . '"," "))]';
}
/**
* @param string[] $match
*
* @return string
*/
private function translateNthChild(array $match)
{
$parseResult = $this->parseNth($match);
if (isset($parseResult[self::MULTIPLIER])) {
if ($parseResult[self::MULTIPLIER] < 0) {
$parseResult[self::MULTIPLIER] = abs($parseResult[self::MULTIPLIER]);
$xPathExpression = sprintf(
'*[(last() - position()) mod %u = %u]/self::%s',
$parseResult[self::MULTIPLIER],
$parseResult[self::INDEX],
$match[1]
);
} else {
$xPathExpression = sprintf(
'*[position() mod %u = %u]/self::%s',
$parseResult[self::MULTIPLIER],
$parseResult[self::INDEX],
$match[1]
);
}
} else {
$xPathExpression = sprintf('*[%u]/self::%s', $parseResult[self::INDEX], $match[1]);
}
return $xPathExpression;
}
/**
* @param string[] $match
*
* @return string
*/
private function translateNthOfType(array $match)
{
$parseResult = $this->parseNth($match);
if (isset($parseResult[self::MULTIPLIER])) {
if ($parseResult[self::MULTIPLIER] < 0) {
$parseResult[self::MULTIPLIER] = abs($parseResult[self::MULTIPLIER]);
$xPathExpression = sprintf(
'%s[(last() - position()) mod %u = %u]',
$match[1],
$parseResult[self::MULTIPLIER],
$parseResult[self::INDEX]
);
} else {
$xPathExpression = sprintf(
'%s[position() mod %u = %u]',
$match[1],
$parseResult[self::MULTIPLIER],
$parseResult[self::INDEX]
);
}
} else {
$xPathExpression = sprintf('%s[%u]', $match[1], $parseResult[self::INDEX]);
}
return $xPathExpression;
}
/**
* @param string[] $match
*
* @return int[]
*/
private function parseNth(array $match)
{
if (in_array(strtolower($match[2]), array('even', 'odd'), true)) {
// we have "even" or "odd"
$index = strtolower($match[2]) === 'even' ? 0 : 1;
return array(self::MULTIPLIER => 2, self::INDEX => $index);
}
if (stripos($match[2], 'n') === false) {
// if there is a multiplier
$index = (int) str_replace(' ', '', $match[2]);
return array(self::INDEX => $index);
}
if (isset($match[3])) {
$multipleTerm = str_replace($match[3], '', $match[2]);
$index = (int) str_replace(' ', '', $match[3]);
} else {
$multipleTerm = $match[2];
$index = 0;
}
$multiplier = str_ireplace('n', '', $multipleTerm);
if ($multiplier === '') {
$multiplier = 1;
} elseif ($multiplier === '0') {
return array(self::INDEX => $index);
} else {
$multiplier = (int) $multiplier;
}
while ($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 $cssDeclarationsBlock the CSS declarations block without the curly braces, may be empty
*
* @return string[]
* the CSS declarations with the property names as array keys and the property values as array values
*/
private function parseCssDeclarationsBlock($cssDeclarationsBlock)
{
if (isset($this->caches[self::CACHE_KEY_CSS_DECLARATIONS_BLOCK][$cssDeclarationsBlock])) {
return $this->caches[self::CACHE_KEY_CSS_DECLARATIONS_BLOCK][$cssDeclarationsBlock];
}
$properties = array();
$declarations = preg_split('/;(?!base64|charset)/', $cssDeclarationsBlock);
foreach ($declarations as $declaration) {
$matches = array();
if (!preg_match('/^([A-Za-z\\-]+)\\s*:\\s*(.+)$/', trim($declaration), $matches)) {
continue;
}
$propertyName = strtolower($matches[1]);
$propertyValue = $matches[2];
$properties[$propertyName] = $propertyValue;
}
$this->caches[self::CACHE_KEY_CSS_DECLARATIONS_BLOCK][$cssDeclarationsBlock] = $properties;
return $properties;
}
/**
* Find the nodes that are not to be emogrified.
*
* @param \DOMXPath $xPath
*
* @return \DOMElement[]
*/
private function getNodesToExclude(DOMXPath $xPath)
{
$excludedNodes = array();
foreach (array_keys($this->excludedSelectors) as $selectorToExclude) {
foreach ($xPath->query($this->translateCssToXpath($selectorToExclude)) as $node) {
$excludedNodes[] = $node;
}
}
return $excludedNodes;
}
/**
* Handles invalid xPath expression warnings, generated by process() method,
* during querying \DOMDocument and trigger \InvalidArgumentException
* with invalid selector.
*
* @param int $type
* @param string $message
* @param string $file
* @param int $line
* @param array $context
*
* @return bool always false
*
* @throws \InvalidArgumentException
*/
public function handleXpathError($type, $message, $file, $line, array $context)
{
if ($type === E_WARNING && isset($context['cssRule']['selector'])) {
throw new InvalidArgumentException(
sprintf(
'%s in selector >> %s << in %s on line %s',
$message,
$context['cssRule']['selector'],
$file,
$line
)
);
}
// the normal error handling continues when handler return false
return false;
}
}