JEMBOT MAWOT Bypass Shell
<?php
declare(strict_types=1);
namespace Pelago\Emogrifier;
use Pelago\Emogrifier\HtmlProcessor\AbstractHtmlProcessor;
use Pelago\Emogrifier\Utilities\CssConcatenator;
use Symfony\Component\CssSelector\CssSelectorConverter;
use Symfony\Component\CssSelector\Exception\ParseException;
/**
* This class provides functions for converting CSS styles into inline style attributes in your HTML code.
*
* For Emogrifier 3.0.0, this will be the successor to the \Pelago\Emogrifier class (which then will be deprecated).
*
* For more information, please see the README.md file.
*
* @author Cameron Brooks
* @author Jaime Prado
* @author Oliver Klee <github@oliverklee.de>
* @author Roman Ožana <ozana@omdesign.cz>
* @author Sander Kruger <s.kruger@invessel.com>
* @author Zoli Szabó <zoli.szabo+github@gmail.com>
*/
class CssInliner extends AbstractHtmlProcessor
{
/**
* @var int
*/
private const CACHE_KEY_CSS = 0;
/**
* @var int
*/
private const CACHE_KEY_SELECTOR = 1;
/**
* @var int
*/
private const CACHE_KEY_CSS_DECLARATIONS_BLOCK = 2;
/**
* @var int
*/
private const CACHE_KEY_COMBINED_STYLES = 3;
/**
* This regular expression pattern will match any uninlinable at-rule with nested statements, along with any
* whitespace immediately following. Currently, any at-rule apart from `@media` is considered uninlinable. The
* first capturing group matches the at sign and identifier (e.g. `@font-face`). The second capturing group matches
* the nested statements along with their enclosing curly brackets (i.e. `{...}`), and via `(?2)` will match deeper
* nested blocks recursively.
*
* @var string
*/
private const UNINLINABLE_AT_RULE_MATCHER
= '/(@(?!media\\b)[\\w\\-]++)[^\\{]*+(\\{[^\\{\\}]*+(?:(?2)[^\\{\\}]*+)*+\\})\\s*+/i';
/**
* Regular expression component matching a static pseudo class in a selector, without the preceding ":",
* for which the applicable elements can be determined (by converting the selector to an XPath expression).
* (Contains alternation without a group and is intended to be placed within a capturing, non-capturing or lookahead
* group, as appropriate for the usage context.)
*
* @var string
*/
private const PSEUDO_CLASS_MATCHER
= 'empty|(?:first|last|nth(?:-last)?+|only)-(?:child|of-type)|not\\([[:ascii:]]*\\)';
/**
* This regular expression componenet matches an `...of-type` pseudo class name, without the preceding ":". These
* pseudo-classes can currently online be inlined if they have an associated type in the selector expression.
*
* @var string
*/
private const OF_TYPE_PSEUDO_CLASS_MATCHER = '(?:first|last|nth(?:-last)?+|only)-of-type';
/**
* regular expression component to match a selector combinator
*
* @var string
*/
private const COMBINATOR_MATCHER = '(?:\\s++|\\s*+[>+~]\\s*+)(?=[[:alpha:]_\\-.#*:\\[])';
/**
* @var bool[]
*/
private $excludedSelectors = [];
/**
* @var bool[]
*/
private $allowedMediaTypes = ['all' => true, 'screen' => true, 'print' => true];
/**
* @var mixed[]
*/
private $caches = [
self::CACHE_KEY_CSS => [],
self::CACHE_KEY_SELECTOR => [],
self::CACHE_KEY_CSS_DECLARATIONS_BLOCK => [],
self::CACHE_KEY_COMBINED_STYLES => [],
];
/**
* @var CssSelectorConverter
*/
private $cssSelectorConverter = null;
/**
* the visited nodes with the XPath paths as array keys
*
* @var \DOMElement[]
*/
private $visitedNodes = [];
/**
* 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 = [];
/**
* 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;
/**
* For calculating selector precedence order.
* Keys are a regular expression part to match before a CSS name.
* Values are a multiplier factor per match to weight specificity.
*
* @var int[]
*/
private $selectorPrecedenceMatchers = [
// IDs: worth 10000
'\\#' => 10000,
// classes, attributes, pseudo-classes (not pseudo-elements) except `:not`: worth 100
'(?:\\.|\\[|(?<!:):(?!not\\())' => 100,
// elements (not attribute values or `:not`), pseudo-elements: worth 1
'(?:(?<![="\':\\w\\-])|::)' => 1,
];
/**
* array of data describing CSS rules which apply to the document but cannot be inlined, in the format returned by
* `parseCssRules`
*
* @var string[][]
*/
private $matchingUninlinableCssRules = null;
/**
* Emogrifier will throw Exceptions when it encounters an error instead of silently ignoring them.
*
* @var bool
*/
private $debug = false;
/**
* Inlines the given CSS into the existing HTML.
*
* @param string $css the CSS to inline, must be UTF-8-encoded
*
* @return self fluent interface
*
* @throws ParseException in debug mode, if an invalid selector is encountered
* @throws \RuntimeException in debug mode, if an internal PCRE error occurs
*/
public function inlineCss(string $css = ''): self
{
$this->clearAllCaches();
$this->purgeVisitedNodes();
$this->normalizeStyleAttributesOfAllNodes();
$combinedCss = $css;
// grab any existing style blocks from the HTML and append them to the existing CSS
// (these blocks should be appended so as to have precedence over conflicting styles in the existing CSS)
if ($this->isStyleBlocksParsingEnabled) {
$combinedCss .= $this->getCssFromAllStyleNodes();
}
$cssWithoutComments = $this->removeCssComments($combinedCss);
[$cssWithoutCommentsCharsetOrImport, $cssImportRules]
= $this->extractImportAndCharsetRules($cssWithoutComments);
[$cssWithoutCommentsOrUninlinableAtRules, $cssAtRules]
= $this->extractUninlinableCssAtRules($cssWithoutCommentsCharsetOrImport);
$uninlinableCss = $cssImportRules . $cssAtRules;
$excludedNodes = $this->getNodesToExclude();
$cssRules = $this->parseCssRules($cssWithoutCommentsOrUninlinableAtRules);
$cssSelectorConverter = $this->getCssSelectorConverter();
foreach ($cssRules['inlinable'] as $cssRule) {
try {
$nodesMatchingCssSelectors = $this->xPath->query($cssSelectorConverter->toXPath($cssRule['selector']));
} catch (ParseException $e) {
if ($this->debug) {
throw $e;
}
continue;
}
/** @var \DOMElement $node */
foreach ($nodesMatchingCssSelectors as $node) {
if (\in_array($node, $excludedNodes, true)) {
continue;
}
$this->copyInlinableCssToStyleAttribute($node, $cssRule);
}
}
if ($this->isInlineStyleAttributesParsingEnabled) {
$this->fillStyleAttributesWithMergedStyles();
}
$this->removeImportantAnnotationFromAllInlineStyles();
$this->determineMatchingUninlinableCssRules($cssRules['uninlinable']);
$this->copyUninlinableCssToStyleNode($uninlinableCss);
return $this;
}
/**
* Disables the parsing of inline styles.
*
* @return self fluent interface
*/
public function disableInlineStyleAttributesParsing(): self
{
$this->isInlineStyleAttributesParsingEnabled = false;
return $this;
}
/**
* Disables the parsing of <style> blocks.
*
* @return self fluent interface
*/
public function disableStyleBlocksParsing(): self
{
$this->isStyleBlocksParsingEnabled = false;
return $this;
}
/**
* Marks a media query type to keep.
*
* @param string $mediaName the media type name, e.g., "braille"
*
* @return self fluent interface
*/
public function addAllowedMediaType(string $mediaName): self
{
$this->allowedMediaTypes[$mediaName] = true;
return $this;
}
/**
* Drops a media query type from the allowed list.
*
* @param string $mediaName the tag name, e.g., "braille"
*
* @return self fluent interface
*/
public function removeAllowedMediaType(string $mediaName): self
{
if (isset($this->allowedMediaTypes[$mediaName])) {
unset($this->allowedMediaTypes[$mediaName]);
}
return $this;
}
/**
* 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 self fluent interface
*/
public function addExcludedSelector(string $selector): self
{
$this->excludedSelectors[$selector] = true;
return $this;
}
/**
* No longer excludes the nodes matching this selector from emogrification.
*
* @param string $selector the selector to no longer exclude, e.g., ".editor"
*
* @return self fluent interface
*/
public function removeExcludedSelector(string $selector): self
{
if (isset($this->excludedSelectors[$selector])) {
unset($this->excludedSelectors[$selector]);
}
return $this;
}
/**
* Sets the debug mode.
*
* @param bool $debug set to true to enable debug mode
*
* @return self fluent interface
*/
public function setDebug(bool $debug): self
{
$this->debug = $debug;
return $this;
}
/**
* Gets the array of selectors present in the CSS provided to `inlineCss()` for which the declarations could not be
* applied as inline styles, but which may affect elements in the HTML. The relevant CSS will have been placed in a
* `<style>` element. The selectors may include those used within `@media` rules or those involving dynamic
* pseudo-classes (such as `:hover`) or pseudo-elements (such as `::after`).
*
* @return string[]
*
* @throws \BadMethodCallException if `inlineCss` has not been called first
*/
public function getMatchingUninlinableSelectors(): array
{
if ($this->matchingUninlinableCssRules === null) {
throw new \BadMethodCallException('inlineCss must be called first', 1568385221);
}
return \array_column($this->matchingUninlinableCssRules, 'selector');
}
/**
* Clears all caches.
*/
private function clearAllCaches(): void
{
$this->caches = [
self::CACHE_KEY_CSS => [],
self::CACHE_KEY_SELECTOR => [],
self::CACHE_KEY_CSS_DECLARATIONS_BLOCK => [],
self::CACHE_KEY_COMBINED_STYLES => [],
];
}
/**
* Purges the visited nodes.
*/
private function purgeVisitedNodes(): void
{
$this->visitedNodes = [];
$this->styleAttributesForNodes = [];
}
/**
* Parses the document and normalizes 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 stores a reference of nodes with existing inline styles so we don't overwrite them.
*/
private function normalizeStyleAttributesOfAllNodes(): void
{
/** @var \DOMElement $node */
foreach ($this->getAllNodesWithStyleAttribute() as $node) {
if ($this->isInlineStyleAttributesParsingEnabled) {
$this->normalizeStyleAttributes($node);
}
// Remove style attribute in every case, so we can add them back (if inline style attributes
// parsing is enabled) to the end of the style list, thus keeping the right priority of CSS rules;
// else original inline style rules may remain at the beginning of the final inline style definition
// of a node, which may give not the desired results
$node->removeAttribute('style');
}
}
/**
* Returns a list with all DOM nodes that have a style attribute.
*
* @return \DOMNodeList
*/
private function getAllNodesWithStyleAttribute(): \DOMNodeList
{
return $this->xPath->query('//*[@style]');
}
/**
* Normalizes the value of the "style" attribute and saves it.
*
* @param \DOMElement $node
*/
private function normalizeStyleAttributes(\DOMElement $node): void
{
$normalizedOriginalStyle = \preg_replace_callback(
'/-?+[_a-zA-Z][\\w\\-]*+(?=:)/S',
static function (array $m) {
return \strtolower($m[0]);
},
$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);
}
/**
* 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(string $cssDeclarationsBlock): array
{
if (isset($this->caches[self::CACHE_KEY_CSS_DECLARATIONS_BLOCK][$cssDeclarationsBlock])) {
return $this->caches[self::CACHE_KEY_CSS_DECLARATIONS_BLOCK][$cssDeclarationsBlock];
}
$properties = [];
foreach (\preg_split('/;(?!base64|charset)/', $cssDeclarationsBlock) as $declaration) {
$matches = [];
if (!\preg_match('/^([A-Za-z\\-]+)\\s*:\\s*(.+)$/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;
}
/**
* Returns CSS content.
*
* @return string
*/
private function getCssFromAllStyleNodes(): string
{
$styleNodes = $this->xPath->query('//style');
if ($styleNodes === false) {
return '';
}
$css = '';
foreach ($styleNodes as $styleNode) {
$css .= "\n\n" . $styleNode->nodeValue;
$parentNode = $styleNode->parentNode;
if ($parentNode instanceof \DOMNode) {
$parentNode->removeChild($styleNode);
}
}
return $css;
}
/**
* Removes comments from the supplied CSS.
*
* @param string $css
*
* @return string CSS with the comments removed
*/
private function removeCssComments(string $css): string
{
return \preg_replace('%/\\*[^*]*+(?:\\*(?!/)[^*]*+)*+\\*/%', '', $css);
}
/**
* Extracts `@import` and `@charset` rules from the supplied CSS. These rules must not be preceded by any other
* rules, or they will be ignored. (From the CSS 2.1 specification: "CSS 2.1 user agents must ignore any '@import'
* rule that occurs inside a block or after any non-ignored statement other than an @charset or an @import rule."
* Note also that `@charset` is case sensitive whereas `@import` is not.)
*
* @param string $css CSS with comments removed
*
* @return string[] The first element is the CSS with the valid `@import` and `@charset` rules removed. The second
* element contains a concatenation of the valid `@import` rules, each followed by whatever whitespace
* followed it in the original CSS (so that either unminified or minified formatting is preserved); if there
* were no `@import` rules, it will be an empty string. The (valid) `@charset` rules are discarded.
*/
private function extractImportAndCharsetRules(string $css): array
{
$possiblyModifiedCss = $css;
$importRules = '';
while (
\preg_match(
'/^\\s*+(@((?i)import(?-i)|charset)\\s[^;]++;\\s*+)/',
$possiblyModifiedCss,
$matches
)
) {
[$fullMatch, $atRuleAndFollowingWhitespace, $atRuleName] = $matches;
if (\strtolower($atRuleName) === 'import') {
$importRules .= $atRuleAndFollowingWhitespace;
}
$possiblyModifiedCss = \substr($possiblyModifiedCss, \strlen($fullMatch));
}
return [$possiblyModifiedCss, $importRules];
}
/**
* Extracts uninlinable at-rules with nested statements (i.e. a block enclosed in curly brackets) from the supplied
* CSS. Currently, any such at-rule apart from `@media` is considered uninlinable. These rules can be placed
* anywhere in the CSS and are not case sensitive. `@font-face` rules will be checked for validity, though other
* at-rules will be assumed to be valid.
*
* @param string $css CSS with comments, import and charset removed
*
* @return string[] The first element is the CSS with the at-rules removed. The second element contains a
* concatenation of the valid at-rules, each followed by whatever whitespace followed it in the
* original CSS (so that either unminified or minified formatting is preserved); if there were no
* at-rules, it will be an empty string.
*/
private function extractUninlinableCssAtRules(string $css): array
{
$possiblyModifiedCss = $css;
$atRules = '';
while (
\preg_match(
self::UNINLINABLE_AT_RULE_MATCHER,
$possiblyModifiedCss,
$matches
)
) {
[$fullMatch, $atRuleName] = $matches;
if ($this->isValidAtRule($atRuleName, $fullMatch)) {
$atRules .= $fullMatch;
}
$possiblyModifiedCss = \str_replace($fullMatch, '', $possiblyModifiedCss);
}
return [$possiblyModifiedCss, $atRules];
}
/**
* Tests if an at-rule is valid. Currently only `@font-face` rules are checked for validity; others are assumed to
* be valid.
*
* @param string $atIdentifier name of the at-rule with the preceding at sign
* @param string $rule full content of the rule, including the at-identifier
*
* @return bool
*/
private function isValidAtRule(string $atIdentifier, string $rule): bool
{
if (\strcasecmp($atIdentifier, '@font-face') === 0) {
return \stripos($rule, 'font-family') !== false && \stripos($rule, 'src') !== false;
}
return true;
}
/**
* Find the nodes that are not to be emogrified.
*
* @return \DOMElement[]
*
* @throws ParseException
*/
private function getNodesToExclude(): array
{
$excludedNodes = [];
foreach (\array_keys($this->excludedSelectors) as $selectorToExclude) {
try {
$matchingNodes = $this->xPath->query($this->getCssSelectorConverter()->toXPath($selectorToExclude));
} catch (ParseException $e) {
if ($this->debug) {
throw $e;
}
continue;
}
foreach ($matchingNodes as $node) {
$excludedNodes[] = $node;
}
}
return $excludedNodes;
}
/**
* @return CssSelectorConverter
*/
private function getCssSelectorConverter(): CssSelectorConverter
{
if ($this->cssSelectorConverter === null) {
$this->cssSelectorConverter = new CssSelectorConverter();
}
return $this->cssSelectorConverter;
}
/**
* Extracts and parses the individual rules from a CSS string.
*
* @param string $css a string of raw CSS code with comments removed
*
* @return string[][][] A 2-entry array with the key "inlinable" containing rules which can be inlined as `style`
* attributes and the key "uninlinable" containing rules which cannot. Each value is an array of string
* sub-arrays with the keys
* "media" (the media query string, e.g. "@media screen and (max-width: 480px)",
* or an empty string if not from a `@media` rule),
* "selector" (the CSS selector, e.g., "*" or "header h1"),
* "hasUnmatchablePseudo" (true if that selector contains pseudo-elements or dynamic pseudo-classes
* such that the declarations cannot be applied inline),
* "declarationsBlock" (the semicolon-separated CSS declarations for that selector,
* e.g., "color: red; height: 4px;"),
* and "line" (the line number e.g. 42)
*/
private function parseCssRules(string $css): array
{
$cssKey = \md5($css);
if (isset($this->caches[self::CACHE_KEY_CSS][$cssKey])) {
return $this->caches[self::CACHE_KEY_CSS][$cssKey];
}
$matches = $this->getCssRuleMatches($css);
$cssRules = [
'inlinable' => [],
'uninlinable' => [],
];
foreach ($matches as $key => $cssRule) {
$cssDeclaration = \trim($cssRule['declarations']);
if ($cssDeclaration === '') {
continue;
}
foreach (\explode(',', $cssRule['selectors']) as $selector) {
// don't process pseudo-elements and behavioral (dynamic) pseudo-classes;
// only allow structural pseudo-classes
$hasPseudoElement = \strpos($selector, '::') !== false;
$hasUnmatchablePseudo = $hasPseudoElement || $this->hasUnsupportedPseudoClass($selector);
$parsedCssRule = [
'media' => $cssRule['media'],
'selector' => \trim($selector),
'hasUnmatchablePseudo' => $hasUnmatchablePseudo,
'declarationsBlock' => $cssDeclaration,
// keep track of where it appears in the file, since order is important
'line' => $key,
];
$ruleType = ($cssRule['media'] === '' && !$hasUnmatchablePseudo) ? 'inlinable' : 'uninlinable';
$cssRules[$ruleType][] = $parsedCssRule;
}
}
\usort($cssRules['inlinable'], [$this, 'sortBySelectorPrecedence']);
$this->caches[self::CACHE_KEY_CSS][$cssKey] = $cssRules;
return $cssRules;
}
/**
* Tests if a selector contains a pseudo-class which would mean it cannot be converted to an XPath expression for
* inlining CSS declarations.
*
* Any pseudo class that does not match {@see PSEUDO_CLASS_MATCHER} cannot be converted. Additionally, `...of-type`
* pseudo-classes cannot be converted if they are not associated with a type selector.
*
* @param string $selector
*
* @return bool
*/
private function hasUnsupportedPseudoClass(string $selector): bool
{
if (\preg_match('/:(?!' . self::PSEUDO_CLASS_MATCHER . ')[\\w\\-]/i', $selector)) {
return true;
}
if (!\preg_match('/:(?:' . self::OF_TYPE_PSEUDO_CLASS_MATCHER . ')/i', $selector)) {
return false;
}
foreach (\preg_split('/' . self::COMBINATOR_MATCHER . '/', $selector) as $selectorPart) {
if ($this->selectorPartHasUnsupportedOfTypePseudoClass($selectorPart)) {
return true;
}
}
return false;
}
/**
* Tests if part of a selector contains an `...of-type` pseudo-class such that it cannot be converted to an XPath
* expression.
*
* @param string $selectorPart part of a selector which has been split up at combinators
*
* @return bool `true` if the selector part does not have a type but does have an `...of-type` pseudo-class
*/
private function selectorPartHasUnsupportedOfTypePseudoClass(string $selectorPart): bool
{
if (\preg_match('/^[\\w\\-]/', $selectorPart)) {
return false;
}
return (bool)\preg_match('/:(?:' . self::OF_TYPE_PSEUDO_CLASS_MATCHER . ')/i', $selectorPart);
}
/**
* @param string[] $a
* @param string[] $b
*
* @return int
*/
private function sortBySelectorPrecedence(array $a, array $b): int
{
$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(string $selector): int
{
$selectorKey = \md5($selector);
if (isset($this->caches[self::CACHE_KEY_SELECTOR][$selectorKey])) {
return $this->caches[self::CACHE_KEY_SELECTOR][$selectorKey];
}
$precedence = 0;
foreach ($this->selectorPrecedenceMatchers as $matcher => $value) {
if (\trim($selector) === '') {
break;
}
$number = 0;
$selector = \preg_replace('/' . $matcher . '\\w+/', '', $selector, -1, $number);
$precedence += ($value * (int)$number);
}
$this->caches[self::CACHE_KEY_SELECTOR][$selectorKey] = $precedence;
return $precedence;
}
/**
* Parses a string of CSS into the media query, selectors and declarations for each ruleset in order.
*
* @param string $css CSS with comments removed
*
* @return array<array-key, array<string, string>> Array of string sub-arrays with the keys
* "media" (the media query string, e.g. "@media screen and (max-width: 480px)",
* or an empty string if not from an `@media` rule),
* "selectors" (the CSS selector(s), e.g., "*" or "h1, h2"),
* "declarations" (the semicolon-separated CSS declarations for that/those selector(s),
* e.g., "color: red; height: 4px;"),
*/
private function getCssRuleMatches(string $css): array
{
$splitCss = $this->splitCssAndMediaQuery($css);
$ruleMatches = [];
foreach ($splitCss as $cssPart) {
// process each part for selectors and definitions
\preg_match_all('/(?:^|[\\s^{}]*)([^{]+){([^}]*)}/mi', $cssPart['css'], $matches, PREG_SET_ORDER);
/** @var string[] $cssRule */
foreach ($matches as $cssRule) {
$ruleMatches[] = [
'media' => $cssPart['media'],
'selectors' => $cssRule[1],
'declarations' => $cssRule[2],
];
}
}
return $ruleMatches;
}
/**
* Splits input CSS code into an array of parts for different media queries, in order.
* Each part is an array where:
*
* - key "css" will contain clean CSS code (for @media rules this will be the group rule body within "{...}")
* - key "media" will contain "@media " followed by the media query list, for all allowed media queries,
* or an empty string for CSS not within a media query
*
* Example:
*
* The CSS code
*
* "@import "file.css"; h1 { color:red; } @media { h1 {}} @media tv { h1 {}}"
*
* will be parsed into the following array:
*
* 0 => [
* "css" => "h1 { color:red; }",
* "media" => ""
* ],
* 1 => [
* "css" => " h1 {}",
* "media" => "@media "
* ]
*
* @param string $css
*
* @return string[][]
*/
private function splitCssAndMediaQuery(string $css): array
{
$mediaTypesExpression = '';
if (!empty($this->allowedMediaTypes)) {
$mediaTypesExpression = '|' . \implode('|', \array_keys($this->allowedMediaTypes));
}
$mediaRuleBodyMatcher = '[^{]*+{(?:[^{}]*+{.*})?\\s*+}\\s*+';
$cssSplitForAllowedMediaTypes = \preg_split(
'#(@media\\s++(?:only\\s++)?+(?:(?=[{(])' . $mediaTypesExpression . ')' . $mediaRuleBodyMatcher
. ')#misU',
$css,
-1,
PREG_SPLIT_DELIM_CAPTURE
);
// filter the CSS outside/between allowed @media rules
$cssCleaningMatchers = [
'import/charset directives' => '/\\s*+@(?:import|charset)\\s[^;]++;/i',
'remaining media enclosures' => '/\\s*+@media\\s' . $mediaRuleBodyMatcher . '/isU',
];
$splitCss = [];
foreach ($cssSplitForAllowedMediaTypes as $index => $cssPart) {
$isMediaRule = $index % 2 !== 0;
if ($isMediaRule) {
\preg_match('/^([^{]*+){(.*)}[^}]*+$/s', $cssPart, $matches);
$splitCss[] = [
'css' => $matches[2],
'media' => $matches[1],
];
} else {
$cleanedCss = \trim(\preg_replace($cssCleaningMatchers, '', $cssPart));
if ($cleanedCss !== '') {
$splitCss[] = [
'css' => $cleanedCss,
'media' => '',
];
}
}
}
return $splitCss;
}
/**
* Copies $cssRule into the style attribute of $node.
*
* Note: This method does not check whether $cssRule matches $node.
*
* @param \DOMElement $node
* @param string[][] $cssRule
*/
private function copyInlinableCssToStyleAttribute(\DOMElement $node, array $cssRule): void
{
/** @var string $declarationsBlock */
$declarationsBlock = $cssRule['declarationsBlock'];
$newStyleDeclarations = $this->parseCssDeclarationsBlock($declarationsBlock);
if ($newStyleDeclarations === []) {
return;
}
// if it has a style attribute, get it, process it, and append (overwrite) new stuff
if ($node->hasAttribute('style')) {
// break it up into an associative array
$oldStyleDeclarations = $this->parseCssDeclarationsBlock($node->getAttribute('style'));
} else {
$oldStyleDeclarations = [];
}
$node->setAttribute(
'style',
$this->generateStyleStringFromDeclarationsArrays($oldStyleDeclarations, $newStyleDeclarations)
);
}
/**
* 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): string
{
$cacheKey = \serialize([$oldStyles, $newStyles]);
if (isset($this->caches[self::CACHE_KEY_COMBINED_STYLES][$cacheKey])) {
return $this->caches[self::CACHE_KEY_COMBINED_STYLES][$cacheKey];
}
// Unset the overridden styles to preserve order, important if shorthand and individual properties are mixed
foreach ($oldStyles as $attributeName => $attributeValue) {
if (!isset($newStyles[$attributeName])) {
continue;
}
$newAttributeValue = $newStyles[$attributeName];
if (
$this->attributeValueIsImportant($attributeValue)
&& !$this->attributeValueIsImportant($newAttributeValue)
) {
unset($newStyles[$attributeName]);
} else {
unset($oldStyles[$attributeName]);
}
}
$combinedStyles = \array_merge($oldStyles, $newStyles);
$style = '';
foreach ($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(string $attributeValue): bool
{
return (bool)\preg_match('/!\\s*+important$/i', $attributeValue);
}
/**
* Merges styles from styles attributes and style nodes and applies them to the attribute nodes
*/
private function fillStyleAttributesWithMergedStyles(): void
{
foreach ($this->styleAttributesForNodes as $nodePath => $styleAttributesForNode) {
$node = $this->visitedNodes[$nodePath];
$currentStyleAttributes = $this->parseCssDeclarationsBlock($node->getAttribute('style'));
$node->setAttribute(
'style',
$this->generateStyleStringFromDeclarationsArrays(
$currentStyleAttributes,
$styleAttributesForNode
)
);
}
}
/**
* Searches for all nodes with a style attribute and removes the "!important" annotations out of
* the inline style declarations, eventually by rearranging declarations.
*
* @throws \RuntimeException
*/
private function removeImportantAnnotationFromAllInlineStyles(): void
{
foreach ($this->getAllNodesWithStyleAttribute() as $node) {
$this->removeImportantAnnotationFromNodeInlineStyle($node);
}
}
/**
* Removes the "!important" annotations out of the inline style declarations,
* eventually by rearranging declarations.
* Rearranging needed when !important shorthand properties are followed by some of their
* not !important expanded-version properties.
* For example "font: 12px serif !important; font-size: 13px;" must be reordered
* to "font-size: 13px; font: 12px serif;" in order to remain correct.
*
* @param \DOMElement $node
*
* @throws \RuntimeException
*/
private function removeImportantAnnotationFromNodeInlineStyle(\DOMElement $node): void
{
$inlineStyleDeclarations = $this->parseCssDeclarationsBlock($node->getAttribute('style'));
$regularStyleDeclarations = [];
$importantStyleDeclarations = [];
foreach ($inlineStyleDeclarations as $property => $value) {
if ($this->attributeValueIsImportant($value)) {
$importantStyleDeclarations[$property] = $this->pregReplace('/\\s*+!\\s*+important$/i', '', $value);
} else {
$regularStyleDeclarations[$property] = $value;
}
}
$inlineStyleDeclarationsInNewOrder = \array_merge(
$regularStyleDeclarations,
$importantStyleDeclarations
);
$node->setAttribute(
'style',
$this->generateStyleStringFromSingleDeclarationsArray($inlineStyleDeclarationsInNewOrder)
);
}
/**
* Generates a CSS style string suitable to be used inline from the $styleDeclarations property => value array.
*
* @param string[] $styleDeclarations
*
* @return string
*/
private function generateStyleStringFromSingleDeclarationsArray(array $styleDeclarations): string
{
return $this->generateStyleStringFromDeclarationsArrays([], $styleDeclarations);
}
/**
* Determines which of `$cssRules` actually apply to `$this->domDocument`, and sets them in
* `$this->matchingUninlinableCssRules`.
*
* @param string[][] $cssRules the "uninlinable" array of CSS rules returned by `parseCssRules`
*/
private function determineMatchingUninlinableCssRules(array $cssRules): void
{
$this->matchingUninlinableCssRules = \array_filter($cssRules, [$this, 'existsMatchForSelectorInCssRule']);
}
/**
* Checks whether there is at least one matching element for the CSS selector contained in the `selector` element
* of the provided CSS rule.
*
* Any dynamic pseudo-classes will be assumed to apply. If the selector matches a pseudo-element,
* it will test for a match with its originating element.
*
* @param string[] $cssRule
*
* @return bool
*
* @throws ParseException
*/
private function existsMatchForSelectorInCssRule(array $cssRule): bool
{
$selector = $cssRule['selector'];
if ($cssRule['hasUnmatchablePseudo']) {
$selector = $this->removeUnmatchablePseudoComponents($selector);
}
return $this->existsMatchForCssSelector($selector);
}
/**
* Checks whether there is at least one matching element for $cssSelector.
* When not in debug mode, it returns true also for invalid selectors (because they may be valid,
* just not implemented/recognized yet by Emogrifier).
*
* @param string $cssSelector
*
* @return bool
*
* @throws ParseException
*/
private function existsMatchForCssSelector(string $cssSelector): bool
{
try {
$nodesMatchingSelector = $this->xPath->query($this->getCssSelectorConverter()->toXPath($cssSelector));
} catch (ParseException $e) {
if ($this->debug) {
throw $e;
}
return true;
}
return $nodesMatchingSelector !== false && $nodesMatchingSelector->length !== 0;
}
/**
* Removes pseudo-elements and dynamic pseudo-classes from a CSS selector, replacing them with "*" if necessary.
* If such a pseudo-component is within the argument of `:not`, the entire `:not` component is removed or replaced.
*
* @param string $selector
*
* @return string Selector which will match the relevant DOM elements if the pseudo-classes are assumed to apply,
* or in the case of pseudo-elements will match their originating element.
*/
private function removeUnmatchablePseudoComponents(string $selector): string
{
// The regex allows nested brackets via `(?2)`.
// A space is temporarily prepended because the callback can't determine if the match was at the very start.
$selectorWithoutNots = \ltrim(\preg_replace_callback(
'/([\\s>+~]?+):not(\\([^()]*+(?:(?2)[^()]*+)*+\\))/i',
[$this, 'replaceUnmatchableNotComponent'],
' ' . $selector
));
$selectorWithoutUnmatchablePseudoComponents = $this->removeSelectorComponents(
':(?!' . self::PSEUDO_CLASS_MATCHER . '):?+[\\w\\-]++(?:\\([^\\)]*+\\))?+',
$selectorWithoutNots
);
if (
!\preg_match(
'/:(?:' . self::OF_TYPE_PSEUDO_CLASS_MATCHER . ')/i',
$selectorWithoutUnmatchablePseudoComponents
)
) {
return $selectorWithoutUnmatchablePseudoComponents;
}
return \implode('', \array_map(
[$this, 'removeUnsupportedOfTypePseudoClasses'],
\preg_split(
'/(' . self::COMBINATOR_MATCHER . ')/',
$selectorWithoutUnmatchablePseudoComponents,
-1,
PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY
)
));
}
/**
* Helps `removeUnmatchablePseudoComponents()` replace or remove a selector `:not(...)` component if its argument
* contains pseudo-elements or dynamic pseudo-classes.
*
* @param string[] $matches array of elements matched by the regular expression
*
* @return string the full match if there were no unmatchable pseudo components within; otherwise, any preceding
* combinator followed by "*", or an empty string if there was no preceding combinator
*/
private function replaceUnmatchableNotComponent(array $matches): string
{
[$notComponentWithAnyPrecedingCombinator, $anyPrecedingCombinator, $notArgumentInBrackets] = $matches;
if ($this->hasUnsupportedPseudoClass($notArgumentInBrackets)) {
return $anyPrecedingCombinator !== '' ? $anyPrecedingCombinator . '*' : '';
}
return $notComponentWithAnyPrecedingCombinator;
}
/**
* Removes components from a CSS selector, replacing them with "*" if necessary.
*
* @param string $matcher regular expression part to match the components to remove
* @param string $selector
*
* @return string selector which will match the relevant DOM elements if the removed components are assumed to apply
* (or in the case of pseudo-elements will match their originating element)
*/
private function removeSelectorComponents(string $matcher, string $selector): string
{
return \preg_replace(
['/([\\s>+~]|^)' . $matcher . '/i', '/' . $matcher . '/i'],
['$1*', ''],
$selector
);
}
/**
* Removes any `...-of-type` pseudo-classes from part of a CSS selector, if it does not have a type, replacing them
* with "*" if necessary.
*
* @param string $selectorPart part of a selector which has been split up at combinators
*
* @return string selector part which will match the relevant DOM elements if the pseudo-classes are assumed to
* apply
*/
private function removeUnsupportedOfTypePseudoClasses(string $selectorPart): string
{
if (!$this->selectorPartHasUnsupportedOfTypePseudoClass($selectorPart)) {
return $selectorPart;
}
return $this->removeSelectorComponents(
':(?:' . self::OF_TYPE_PSEUDO_CLASS_MATCHER . ')(?:\\([^\\)]*+\\))?+',
$selectorPart
);
}
/**
* Applies `$this->matchingUninlinableCssRules` to `$this->domDocument` by placing them as CSS in a `<style>`
* element.
*
* @param string $uninlinableCss This may contain any `@import` or `@font-face` rules that should precede the CSS
* placed in the `<style>` element. If there are no unlinlinable CSS rules to copy there, a `<style>`
* element will be created containing just `$uninlinableCss`. `$uninlinableCss` may be an empty string;
* if it is, and there are no unlinlinable CSS rules, an empty `<style>` element will not be created.
*/
private function copyUninlinableCssToStyleNode(string $uninlinableCss): void
{
$css = $uninlinableCss;
// avoid including unneeded class dependency if there are no rules
if ($this->matchingUninlinableCssRules !== []) {
$cssConcatenator = new CssConcatenator();
foreach ($this->matchingUninlinableCssRules as $cssRule) {
$cssConcatenator->append([$cssRule['selector']], $cssRule['declarationsBlock'], $cssRule['media']);
}
$css .= $cssConcatenator->getCss();
}
// avoid adding empty style element
if ($css !== '') {
$this->addStyleElementToDocument($css);
}
}
/**
* Adds a style element with $css to $this->domDocument.
*
* This method is protected to allow overriding.
*
* @see https://github.com/MyIntervals/emogrifier/issues/103
*
* @param string $css
*/
protected function addStyleElementToDocument(string $css): void
{
$styleElement = $this->domDocument->createElement('style', $css);
$styleAttribute = $this->domDocument->createAttribute('type');
$styleAttribute->value = 'text/css';
$styleElement->appendChild($styleAttribute);
$headElement = $this->getHeadElement();
$headElement->appendChild($styleElement);
}
/**
* Returns the HEAD element.
*
* This method assumes that there always is a HEAD element.
*
* @return \DOMElement
*/
private function getHeadElement(): \DOMElement
{
return $this->domDocument->getElementsByTagName('head')->item(0);
}
/**
* Wraps `preg_replace`. If an error occurs (which is highly unlikely), either it is logged and the original
* `$subject` is returned, or in debug mode an exception is thrown.
*
* This method does not currently allow `$subject` (and return value) to be an array, because a means of telling
* Psalm that a method returns the same type a particular parameter has not been found (though it knows this for
* `preg_replace`); nor does it currently support the optional parameters.
*
* @param string|string[] $pattern
* @param string|string[] $replacement
* @param string $subject
*
* @return string
*
* @throws \RuntimeException
*/
private function pregReplace($pattern, $replacement, string $subject): string
{
$result = \preg_replace($pattern, $replacement, $subject);
if ($result === null) {
$this->logOrThrowPregLastError();
$result = $subject;
}
return $result;
}
/**
* Obtains the name of the error constant for `preg_last_error` (based on code posted at
* {@see https://www.php.net/manual/en/function.preg-last-error.php#124124}) and puts it into an error message
* which is either passed to `trigger_error` (in non-debug mode) or an exception which is thrown (in debug mode).
*
* @throws \RuntimeException
*/
private function logOrThrowPregLastError(): void
{
$pcreConstants = \get_defined_constants(true)['pcre'];
$pcreErrorConstantNames = \is_array($pcreConstants) ? \array_flip(\array_filter(
$pcreConstants,
function (string $key): bool {
return \substr($key, -6) === '_ERROR';
},
ARRAY_FILTER_USE_KEY
)) : [];
$pregLastError = \preg_last_error();
$message = 'PCRE regex execution error `' . (string)($pcreErrorConstantNames[$pregLastError] ?? $pregLastError)
. '`';
if ($this->debug) {
throw new \RuntimeException($message, 1592870147);
}
\trigger_error($message);
}
}
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