fluent-support / app / Services / Emogrifier.php

Emogrifier.php in Fluent Support – Helpdesk & Customer Support Ticket System 1.10.2, at app/Services/Emogrifier.php

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1	<?php
2
3	namespace FluentSupport\App\Services;
4
5	/**
6	* This class provides functions for converting CSS styles into inline style attributes in your HTML code.
7	*
8	* For more information, please see the README.md file.
9	*
10	* @version 2.0.0
11	*
12	* @author Cameron Brooks
13	* @author Jaime Prado
14	* @author Oliver Klee <github@oliverklee.de>
15	* @author Roman Ožana <ozana@omdesign.cz>
16	* @author Sander Kruger <s.kruger@invessel.com>
17	* @author Zoli Szabó <zoli.szabo+github@gmail.com>
18	*/
19	class Emogrifier
20	{
21	/**
22	* @var int
23	*/
24	const CACHE_KEY_CSS = 0;
25
26	/**
27	* @var int
28	*/
29	const CACHE_KEY_SELECTOR = 1;
30
31	/**
32	* @var int
33	*/
34	const CACHE_KEY_XPATH = 2;
35
36	/**
37	* @var int
38	*/
39	const CACHE_KEY_CSS_DECLARATIONS_BLOCK = 3;
40
41	/**
42	* @var int
43	*/
44	const CACHE_KEY_COMBINED_STYLES = 4;
45
46	/**
47	* for calculating nth-of-type and nth-child selectors
48	*
49	* @var int
50	*/
51	const INDEX = 0;
52
53	/**
54	* for calculating nth-of-type and nth-child selectors
55	*
56	* @var int
57	*/
58	const MULTIPLIER = 1;
59
60	/**
61	* @var string
62	*/
63	const ID_ATTRIBUTE_MATCHER = '/(\\w+)?\\#([\\w\\-]+)/';
64
65	/**
66	* @var string
67	*/
68	const CLASS_ATTRIBUTE_MATCHER = '/(\\w+\|[\\*\\]])?((\\.[\\w\\-]+)+)/';
69
70	/**
71	* @var string
72	*/
73	const CONTENT_TYPE_META_TAG = '<meta http-equiv="Content-Type" content="text/html; charset=utf-8">';
74
75	/**
76	* @var string
77	*/
78	const DEFAULT_DOCUMENT_TYPE = '<!DOCTYPE html>';
79
80	/**
81	* @var string
82	*/
83	private $html = '';
84
85	/**
86	* @var string
87	*/
88	private $css = '';
89
90	/**
91	* @var bool[]
92	*/
93	private $excludedSelectors = [];
94
95	/**
96	* @var string[]
97	*/
98	private $unprocessableHtmlTags = ['wbr'];
99
100	/**
101	* @var bool[]
102	*/
103	private $allowedMediaTypes = ['all' => true, 'screen' => true, 'print' => true];
104
105	/**
106	* @var mixed[]
107	*/
108	private $caches = [
109	self::CACHE_KEY_CSS => [],
110	self::CACHE_KEY_SELECTOR => [],
111	self::CACHE_KEY_XPATH => [],
112	self::CACHE_KEY_CSS_DECLARATIONS_BLOCK => [],
113	self::CACHE_KEY_COMBINED_STYLES => [],
114	];
115
116	/**
117	* the visited nodes with the XPath paths as array keys
118	*
119	* @var \DOMElement[]
120	*/
121	private $visitedNodes = [];
122
123	/**
124	* the styles to apply to the nodes with the XPath paths as array keys for the outer array
125	* and the attribute names/values as key/value pairs for the inner array
126	*
127	* @var string[][]
128	*/
129	private $styleAttributesForNodes = [];
130
131	/**
132	* Determines whether the "style" attributes of tags in the the HTML passed to this class should be preserved.
133	* If set to false, the value of the style attributes will be discarded.
134	*
135	* @var bool
136	*/
137	private $isInlineStyleAttributesParsingEnabled = true;
138
139	/**
140	* Determines whether the <style> blocks in the HTML passed to this class should be parsed.
141	*
142	* If set to true, the <style> blocks will be removed from the HTML and their contents will be applied to the HTML
143	* via inline styles.
144	*
145	* If set to false, the <style> blocks will be left as they are in the HTML.
146	*
147	* @var bool
148	*/
149	private $isStyleBlocksParsingEnabled = true;
150
151	/**
152	* Determines whether elements with the `display: none` property are
153	* removed from the DOM.
154	*
155	* @var bool
156	*/
157	private $shouldKeepInvisibleNodes = true;
158
159	/**
160	* @var string[]
161	*/
162	private $xPathRules = [
163	// attribute presence
164	'/^\\[(\\w+\|\\w+\\=[\'"]?\\w+[\'"]?)\\]/' => '*[@\\1]',
165	// type and attribute exact value
166	'/(\\w)\\[(\\w+)\\=[\'"]?([\\w\\s]+)[\'"]?\\]/' => '\\1[@\\2="\\3"]',
167	// type and attribute value with ~ (one word within a whitespace-separated list of words)
168	'/([\\w\\]+)\\[(\\w+)[\\s]\\~\\=[\\s]*[\'"]?([\\w\-_\\/]+)[\'"]?\\]/'
169	=> '\\1[contains(concat(" ", @\\2, " "), concat(" ", "\\3", " "))]',
170	// type and attribute value with \| (either exact value match or prefix followed by a hyphen)
171	'/([\\w\\]+)\\[(\\w+)[\\s]\\\|\\=[\\s]*[\'"]?([\\w\-_\\s\\/]+)[\'"]?\\]/'
172	=> '\\1[@\\2="\\3" or starts-with(@\\2, concat("\\3", "-"))]',
173	// type and attribute value with ^ (prefix match)
174	'/([\\w\\]+)\\[(\\w+)[\\s]\\^\\=[\\s]*[\'"]?([\\w\-_\\/]+)[\'"]?\\]/' => '\\1[starts-with(@\\2, "\\3")]',
175	// type and attribute value with * (substring match)
176	'/([\\w\\]+)\\[(\\w+)[\\s]\\\\=[\\s][\'"]?([\\w\-_\\s\\/:;]+)[\'"]?\\]/' => '\\1[contains(@\\2, "\\3")]',
177	// adjacent sibling
178	'/\\s+\\+\\s+/' => '/following-sibling::*[1]/self::',
179	// child
180	'/\\s>\\s/' => '/',
181	// descendant
182	'/\\s+(?=.*[^\\]]{1}$)/' => '//',
183	// type and :first-child
184	'/([^\\/]+):first-child/i' => '*[1]/self::\\1',
185	// type and :last-child
186	'/([^\\/]+):last-child/i' => '*[last()]/self::\\1',
187
188	// The following matcher will break things if it is placed before the adjacent matcher.
189	// So one of the matchers matches either too much or not enough.
190	// type and attribute value with $ (suffix match)
191	'/([\\w\\]+)\\[(\\w+)[\\s]\\$\\=[\\s]*[\'"]?([\\w\-_\\s\\/]+)[\'"]?\\]/'
192	=> '\\1[substring(@\\2, string-length(@\\2) - string-length("\\3") + 1) = "\\3"]',
193	];
194
195	/**
196	* Determines whether CSS styles that have an equivalent HTML attribute
197	* should be mapped and attached to those elements.
198	*
199	* @var bool
200	*/
201	private $shouldMapCssToHtml = false;
202
203	/**
204	* This multi-level array contains simple mappings of CSS properties to
205	* HTML attributes. If a mapping only applies to certain HTML nodes or
206	* only for certain values, the mapping is an object with a whitelist
207	* of nodes and values.
208	*
209	* @var mixed[][]
210	*/
211	private $cssToHtmlMap = [
212	'background-color' => [
213	'attribute' => 'bgcolor',
214	],
215	'text-align' => [
216	'attribute' => 'align',
217	'nodes' => ['p', 'div', 'td'],
218	'values' => ['left', 'right', 'center', 'justify'],
219	],
220	'float' => [
221	'attribute' => 'align',
222	'nodes' => ['table', 'img'],
223	'values' => ['left', 'right'],
224	],
225	'border-spacing' => [
226	'attribute' => 'cellspacing',
227	'nodes' => ['table'],
228	],
229	];
230
231	/**
232	* Emogrifier will throw Exceptions when it encounters an error instead of silently ignoring them.
233	*
234	* @var bool
235	*/
236	private $debug = false;
237
238	/**
239	* The constructor.
240	*
241	* @param string $html the HTML to emogrify, must be UTF-8-encoded
242	* @param string $css the CSS to merge, must be UTF-8-encoded
243	*/
244	public function __construct($html = '', $css = '')
245	{
246	$this->setHtml($html);
247	$this->setCss($css);
248	}
249
250	/**
251	* The destructor.
252	*/
253	public function __destruct()
254	{
255	$this->purgeVisitedNodes();
256	}
257
258	/**
259	* Sets the HTML to emogrify.
260	*
261	* @param string $html the HTML to emogrify, must be UTF-8-encoded
262	*
263	* @return void
264	*/
265	public function setHtml($html)
266	{
267	$this->html = $html;
268	}
269
270	/**
271	* Sets the CSS to merge with the HTML.
272	*
273	* @param string $css the CSS to merge, must be UTF-8-encoded
274	*
275	* @return void
276	*/
277	public function setCss($css)
278	{
279	$this->css = $css;
280	}
281
282	/**
283	* Applies $this->css to $this->html and returns the HTML with the CSS
284	* applied.
285	*
286	* This method places the CSS inline.
287	*
288	* @return string
289	*
290	* @throws \BadMethodCallException
291	*/
292	public function emogrify()
293	{
294	return $this->createAndProcessXmlDocument()->saveHTML();
295	}
296
297	/**
298	* Applies $this->css to $this->html and returns only the HTML content
299	* within the <body> tag.
300	*
301	* This method places the CSS inline.
302	*
303	* @return string
304	*
305	* @throws \BadMethodCallException
306	*/
307	public function emogrifyBodyContent()
308	{
309	$xmlDocument = $this->createAndProcessXmlDocument();
310	$bodyNodeHtml = $xmlDocument->saveHTML($this->getBodyElement($xmlDocument));
311
312	return str_replace(['<body>', '</body>'], '', $bodyNodeHtml);
313	}
314
315	/**
316	* Creates an XML document from $this->html and emogrifies ist.
317	*
318	* @return \DOMDocument
319	*
320	* @throws \BadMethodCallException
321	*/
322	private function createAndProcessXmlDocument()
323	{
324	if ($this->html === '') {
325	throw new \BadMethodCallException('Please set some HTML first.', 1390393096);
326	}
327
328	$xmlDocument = $this->createRawXmlDocument();
329	$this->ensureExistenceOfBodyElement($xmlDocument);
330	$this->process($xmlDocument);
331
332	return $xmlDocument;
333	}
334
335	/**
336	* Applies $this->css to $xmlDocument.
337	*
338	* This method places the CSS inline.
339	*
340	* @param \DOMDocument $xmlDocument
341	*
342	* @return void
343	*
344	* @throws \InvalidArgumentException
345	*/
346	protected function process(\DOMDocument $xmlDocument)
347	{
348	$xPath = new \DOMXPath($xmlDocument);
349	$this->clearAllCaches();
350	$this->purgeVisitedNodes();
351	\set_error_handler([$this, 'handleXpathQueryWarnings'], E_WARNING);
352
353	$this->normalizeStyleAttributesOfAllNodes($xPath);
354
355	// grab any existing style blocks from the html and append them to the existing CSS
356	// (these blocks should be appended so as to have precedence over conflicting styles in the existing CSS)
357	$allCss = $this->css;
358	if ($this->isStyleBlocksParsingEnabled) {
359	$allCss .= $this->getCssFromAllStyleNodes($xPath);
360	}
361
362	$cssParts = $this->splitCssAndMediaQuery($allCss);
363	$excludedNodes = $this->getNodesToExclude($xPath);
364	$cssRules = $this->parseCssRules($cssParts['css']);
365	foreach ($cssRules as $cssRule) {
366	// There's no real way to test "PHP Warning" output generated by the following XPath query unless PHPUnit
367	// converts it to an exception. Unfortunately, this would only apply to tests and not work for production
368	// executions, which can still flood logs/output unnecessarily. Instead, Emogrifier's error handler should
369	// always throw an exception and it must be caught here and only rethrown if in debug mode.
370	try {
371	// \DOMXPath::query will always return a DOMNodeList or an exception when errors are caught.
372	$nodesMatchingCssSelectors = $xPath->query($this->translateCssToXpath($cssRule['selector']));
373	} catch (\InvalidArgumentException $e) {
374	if ($this->debug) {
375	throw $e;
376	}
377	continue;
378	}
379
380	/** @var \DOMElement $node */
381	foreach ($nodesMatchingCssSelectors as $node) {
382	if (in_array($node, $excludedNodes, true)) {
383	continue;
384	}
385	// if it has a style attribute, get it, process it, and append (overwrite) new stuff
386	if ($node->hasAttribute('style')) {
387	// break it up into an associative array
388	$oldStyleDeclarations = $this->parseCssDeclarationsBlock($node->getAttribute('style'));
389	} else {
390	$oldStyleDeclarations = [];
391	}
392	$newStyleDeclarations = $this->parseCssDeclarationsBlock($cssRule['declarationsBlock']);
393	$node->setAttribute(
394	'style',
395	$this->generateStyleStringFromDeclarationsArrays($oldStyleDeclarations, $newStyleDeclarations)
396	);
397	}
398	}
399
400	if ($this->isInlineStyleAttributesParsingEnabled) {
401	$this->fillStyleAttributesWithMergedStyles();
402	}
403
404	if ($this->shouldMapCssToHtml) {
405	$this->mapAllInlineStylesToHtmlAttributes($xPath);
406	}
407
408	if ($this->shouldKeepInvisibleNodes) {
409	$this->removeInvisibleNodes($xPath);
410	}
411
412	$this->removeImportantAnnotationFromAllInlineStyles($xPath);
413
414	$this->copyCssWithMediaToStyleNode($xmlDocument, $xPath, $cssParts['media']);
415
416	\restore_error_handler();
417	}
418
419	/**
420	* Searches for all nodes with a style attribute, transforms the CSS found
421	* to HTML attributes and adds those attributes to each node.
422	*
423	* @param \DOMXPath $xPath
424	*
425	* @return void
426	*/
427	private function mapAllInlineStylesToHtmlAttributes(\DOMXPath $xPath)
428	{
429	/** @var \DOMElement $node */
430	foreach ($this->getAllNodesWithStyleAttribute($xPath) as $node) {
431	$inlineStyleDeclarations = $this->parseCssDeclarationsBlock($node->getAttribute('style'));
432	$this->mapCssToHtmlAttributes($inlineStyleDeclarations, $node);
433	}
434	}
435
436	/**
437	* Searches for all nodes with a style attribute and removes the "!important" annotations out of
438	* the inline style declarations, eventually by rearranging declarations.
439	*
440	* @param \DOMXPath $xPath
441	*
442	* @return void
443	*/
444	private function removeImportantAnnotationFromAllInlineStyles(\DOMXPath $xPath)
445	{
446	foreach ($this->getAllNodesWithStyleAttribute($xPath) as $node) {
447	$this->removeImportantAnnotationFromNodeInlineStyle($node);
448	}
449	}
450
451	/**
452	* Removes the "!important" annotations out of the inline style declarations,
453	* eventually by rearranging declarations.
454	* Rearranging needed when !important shorthand properties are followed by some of their
455	* not !important expanded-version properties.
456	* For example "font: 12px serif !important; font-size: 13px;" must be reordered
457	* to "font-size: 13px; font: 12px serif;" in order to remain correct.
458	*
459	* @param \DOMElement $node
460	*
461	* @return void
462	*/
463	private function removeImportantAnnotationFromNodeInlineStyle(\DOMElement $node)
464	{
465	$inlineStyleDeclarations = $this->parseCssDeclarationsBlock($node->getAttribute('style'));
466	$regularStyleDeclarations = [];
467	$importantStyleDeclarations = [];
468	foreach ($inlineStyleDeclarations as $property => $value) {
469	if ($this->attributeValueIsImportant($value)) {
470	$importantStyleDeclarations[$property] = trim(str_replace('!important', '', $value));
471	} else {
472	$regularStyleDeclarations[$property] = $value;
473	}
474	}
475	$inlineStyleDeclarationsInNewOrder = array_merge(
476	$regularStyleDeclarations,
477	$importantStyleDeclarations
478	);
479	$node->setAttribute(
480	'style',
481	$this->generateStyleStringFromSingleDeclarationsArray($inlineStyleDeclarationsInNewOrder)
482	);
483	}
484
485	/**
486	* Returns a list with all DOM nodes that have a style attribute.
487	*
488	* @param \DOMXPath $xPath
489	*
490	* @return \DOMNodeList
491	*/
492	private function getAllNodesWithStyleAttribute(\DOMXPath $xPath)
493	{
494	return $xPath->query('//*[@style]');
495	}
496
497	/**
498	* Applies $styles to $node.
499	*
500	* This method maps CSS styles to HTML attributes and adds those to the
501	* node.
502	*
503	* @param string[] $styles the new CSS styles taken from the global styles to be applied to this node
504	* @param \DOMElement $node node to apply styles to
505	*
506	* @return void
507	*/
508	private function mapCssToHtmlAttributes(array $styles, \DOMElement $node)
509	{
510	foreach ($styles as $property => $value) {
511	// Strip !important indicator
512	$value = trim(str_replace('!important', '', $value));
513	$this->mapCssToHtmlAttribute($property, $value, $node);
514	}
515	}
516
517	/**
518	* Tries to apply the CSS style to $node as an attribute.
519	*
520	* This method maps a CSS rule to HTML attributes and adds those to the node.
521	*
522	* @param string $property the name of the CSS property to map
523	* @param string $value the value of the style rule to map
524	* @param \DOMElement $node node to apply styles to
525	*
526	* @return void
527	*/
528	private function mapCssToHtmlAttribute($property, $value, \DOMElement $node)
529	{
530	if (!$this->mapSimpleCssProperty($property, $value, $node)) {
531	$this->mapComplexCssProperty($property, $value, $node);
532	}
533	}
534
535	/**
536	* Looks up the CSS property in the mapping table and maps it if it matches the conditions.
537	*
538	* @param string $property the name of the CSS property to map
539	* @param string $value the value of the style rule to map
540	* @param \DOMElement $node node to apply styles to
541	*
542	* @return bool true if the property cab be mapped using the simple mapping table
543	*/
544	private function mapSimpleCssProperty($property, $value, \DOMElement $node)
545	{
546	if (!isset($this->cssToHtmlMap[$property])) {
547	return false;
548	}
549
550	$mapping = $this->cssToHtmlMap[$property];
551	$nodesMatch = !isset($mapping['nodes']) \|\| in_array($node->nodeName, $mapping['nodes'], true);
552	$valuesMatch = !isset($mapping['values']) \|\| in_array($value, $mapping['values'], true);
553	if (!$nodesMatch \|\| !$valuesMatch) {
554	return false;
555	}
556
557	$node->setAttribute($mapping['attribute'], $value);
558
559	return true;
560	}
561
562	/**
563	* Maps CSS properties that need special transformation to an HTML attribute.
564	*
565	* @param string $property the name of the CSS property to map
566	* @param string $value the value of the style rule to map
567	* @param \DOMElement $node node to apply styles to
568	*
569	* @return void
570	*/
571	private function mapComplexCssProperty($property, $value, \DOMElement $node)
572	{
573	$nodeName = $node->nodeName;
574	$isTable = $nodeName === 'table';
575	$isImage = $nodeName === 'img';
576	$isTableOrImage = $isTable \|\| $isImage;
577
578	switch ($property) {
579	case 'background':
580	// Parse out the color, if any
581	$styles = explode(' ', $value);
582	$first = $styles[0];
583	if (!is_numeric($first[0]) && strpos($first, 'url') !== 0) {
584	// This is not a position or image, assume it's a color
585	$node->setAttribute('bgcolor', $first);
586	}
587	break;
588	case 'width':
589	// intentional fall-through
590	case 'height':
591	// Only parse values in px and %, but not values like "auto".
592	if (preg_match('/^\d+(px\|%)$/', $value)) {
593	// Remove 'px'. This regex only conserves numbers and %
594	$number = preg_replace('/[^0-9.%]/', '', $value);
595	$node->setAttribute($property, $number);
596	}
597	break;
598	case 'margin':
599	if ($isTableOrImage) {
600	$margins = $this->parseCssShorthandValue($value);
601	if ($margins['left'] === 'auto' && $margins['right'] === 'auto') {
602	$node->setAttribute('align', 'center');
603	}
604	}
605	break;
606	case 'border':
607	if ($isTableOrImage) {
608	if ($value === 'none' \|\| $value === '0') {
609	$node->setAttribute('border', '0');
610	}
611	}
612	break;
613	default:
614	}
615	}
616
617	/**
618	* Parses a shorthand CSS value and splits it into individual values
619	*
620	* @param string $value a string of CSS value with 1, 2, 3 or 4 sizes
621	* For example: padding: 0 auto;
622	* '0 auto' is split into top: 0, left: auto, bottom: 0,
623	* right: auto.
624	*
625	* @return string[] an array of values for top, right, bottom and left (using these as associative array keys)
626	*/
627	private function parseCssShorthandValue($value)
628	{
629	$values = preg_split('/\\s+/', $value);
630
631	$css = [];
632	$css['top'] = $values[0];
633	$css['right'] = (count($values) > 1) ? $values[1] : $css['top'];
634	$css['bottom'] = (count($values) > 2) ? $values[2] : $css['top'];
635	$css['left'] = (count($values) > 3) ? $values[3] : $css['right'];
636
637	return $css;
638	}
639
640	/**
641	* Extracts and parses the individual rules from a CSS string.
642	*
643	* @param string $css a string of raw CSS code
644	*
645	* @return string[][] an array of string sub-arrays with the keys
646	* "selector" (the CSS selector(s), e.g., "*" or "h1"),
647	* "declarationsBLock" (the semicolon-separated CSS declarations for that selector(s),
648	* e.g., "color: red; height: 4px;"),
649	* and "line" (the line number e.g. 42)
650	*/
651	private function parseCssRules($css)
652	{
653	$cssKey = md5($css);
654	if (!isset($this->caches[self::CACHE_KEY_CSS][$cssKey])) {
655	// process the CSS file for selectors and definitions
656	preg_match_all('/(?:^\|[\\s^{}])([^{]+){([^}])}/mi', $css, $matches, PREG_SET_ORDER);
657
658	$cssRules = [];
659	/** @var string[][] $matches */
660	/** @var string[] $cssRule */
661	foreach ($matches as $key => $cssRule) {
662	$cssDeclaration = trim($cssRule[2]);
663	if ($cssDeclaration === '') {
664	continue;
665	}
666
667	$selectors = explode(',', $cssRule[1]);
668	foreach ($selectors as $selector) {
669	// don't process pseudo-elements and behavioral (dynamic) pseudo-classes;
670	// only allow structural pseudo-classes
671	$hasPseudoElement = strpos($selector, '::') !== false;
672	$hasAnyPseudoClass = (bool)preg_match('/:[a-zA-Z]/', $selector);
673	$hasSupportedPseudoClass = (bool)preg_match(
674	'/:(\\S+\\-(child\|type\$)\|not\\([[:ascii:]]*\$)/i',
675	$selector
676	);
677	if ($hasPseudoElement \|\| ($hasAnyPseudoClass && !$hasSupportedPseudoClass)) {
678	continue;
679	}
680
681	$cssRules[] = [
682	'selector' => trim($selector),
683	'declarationsBlock' => $cssDeclaration,
684	// keep track of where it appears in the file, since order is important
685	'line' => $key,
686	];
687	}
688	}
689
690	usort($cssRules, [$this, 'sortBySelectorPrecedence']);
691
692	$this->caches[self::CACHE_KEY_CSS][$cssKey] = $cssRules;
693	}
694
695	return $this->caches[self::CACHE_KEY_CSS][$cssKey];
696	}
697
698	/**
699	* Disables the parsing of inline styles.
700	*
701	* @return void
702	*/
703	public function disableInlineStyleAttributesParsing()
704	{
705	$this->isInlineStyleAttributesParsingEnabled = false;
706	}
707
708	/**
709	* Disables the parsing of <style> blocks.
710	*
711	* @return void
712	*/
713	public function disableStyleBlocksParsing()
714	{
715	$this->isStyleBlocksParsingEnabled = false;
716	}
717
718	/**
719	* Disables the removal of elements with `display: none` properties.
720	*
721	* @return void
722	*/
723	public function disableInvisibleNodeRemoval()
724	{
725	$this->shouldKeepInvisibleNodes = false;
726	}
727
728	/**
729	* Enables the attachment/override of HTML attributes for which a
730	* corresponding CSS property has been set.
731	*
732	* @return void
733	*/
734	public function enableCssToHtmlMapping()
735	{
736	$this->shouldMapCssToHtml = true;
737	}
738
739	/**
740	* Clears all caches.
741	*
742	* @return void
743	*/
744	private function clearAllCaches()
745	{
746	$this->clearCache(self::CACHE_KEY_CSS);
747	$this->clearCache(self::CACHE_KEY_SELECTOR);
748	$this->clearCache(self::CACHE_KEY_XPATH);
749	$this->clearCache(self::CACHE_KEY_CSS_DECLARATIONS_BLOCK);
750	$this->clearCache(self::CACHE_KEY_COMBINED_STYLES);
751	}
752
753	/**
754	* Clears a single cache by key.
755	*
756	* @param int $key the cache key, must be CACHE_KEY_CSS, CACHE_KEY_SELECTOR, CACHE_KEY_XPATH
757	* or CACHE_KEY_CSS_DECLARATION_BLOCK
758	*
759	* @return void
760	*
761	* @throws \InvalidArgumentException
762	*/
763	private function clearCache($key)
764	{
765	$allowedCacheKeys = [
766	self::CACHE_KEY_CSS,
767	self::CACHE_KEY_SELECTOR,
768	self::CACHE_KEY_XPATH,
769	self::CACHE_KEY_CSS_DECLARATIONS_BLOCK,
770	self::CACHE_KEY_COMBINED_STYLES,
771	];
772	if (!in_array($key, $allowedCacheKeys, true)) {
773	throw new \InvalidArgumentException('Invalid cache key: ' . esc_html($key), 1391822035);
774	}
775
776	$this->caches[$key] = [];
777	}
778
779	/**
780	* Purges the visited nodes.
781	*
782	* @return void
783	*/
784	private function purgeVisitedNodes()
785	{
786	$this->visitedNodes = [];
787	$this->styleAttributesForNodes = [];
788	}
789
790	/**
791	* Marks a tag for removal.
792	*
793	* There are some HTML tags that DOMDocument cannot process, and it will throw an error if it encounters them.
794	* In particular, DOMDocument will complain if you try to use HTML5 tags in an XHTML document.
795	*
796	* Note: The tags will not be removed if they have any content.
797	*
798	* @param string $tagName the tag name, e.g., "p"
799	*
800	* @return void
801	*/
802	public function addUnprocessableHtmlTag($tagName)
803	{
804	$this->unprocessableHtmlTags[] = $tagName;
805	}
806
807	/**
808	* Drops a tag from the removal list.
809	*
810	* @param string $tagName the tag name, e.g., "p"
811	*
812	* @return void
813	*/
814	public function removeUnprocessableHtmlTag($tagName)
815	{
816	$key = array_search($tagName, $this->unprocessableHtmlTags, true);
817	if ($key !== false) {
818	unset($this->unprocessableHtmlTags[$key]);
819	}
820	}
821
822	/**
823	* Marks a media query type to keep.
824	*
825	* @param string $mediaName the media type name, e.g., "braille"
826	*
827	* @return void
828	*/
829	public function addAllowedMediaType($mediaName)
830	{
831	$this->allowedMediaTypes[$mediaName] = true;
832	}
833
834	/**
835	* Drops a media query type from the allowed list.
836	*
837	* @param string $mediaName the tag name, e.g., "braille"
838	*
839	* @return void
840	*/
841	public function removeAllowedMediaType($mediaName)
842	{
843	if (isset($this->allowedMediaTypes[$mediaName])) {
844	unset($this->allowedMediaTypes[$mediaName]);
845	}
846	}
847
848	/**
849	* Adds a selector to exclude nodes from emogrification.
850	*
851	* Any nodes that match the selector will not have their style altered.
852	*
853	* @param string $selector the selector to exclude, e.g., ".editor"
854	*
855	* @return void
856	*/
857	public function addExcludedSelector($selector)
858	{
859	$this->excludedSelectors[$selector] = true;
860	}
861
862	/**
863	* No longer excludes the nodes matching this selector from emogrification.
864	*
865	* @param string $selector the selector to no longer exclude, e.g., ".editor"
866	*
867	* @return void
868	*/
869	public function removeExcludedSelector($selector)
870	{
871	if (isset($this->excludedSelectors[$selector])) {
872	unset($this->excludedSelectors[$selector]);
873	}
874	}
875
876	/**
877	* This removes styles from your email that contain display:none.
878	* We need to look for display:none, but we need to do a case-insensitive search. Since DOMDocument only
879	* supports XPath 1.0, lower-case() isn't available to us. We've thus far only set attributes to lowercase,
880	* not attribute values. Consequently, we need to translate() the letters that would be in 'NONE' ("NOE")
881	* to lowercase.
882	*
883	* @param \DOMXPath $xPath
884	*
885	* @return void
886	*/
887	private function removeInvisibleNodes(\DOMXPath $xPath)
888	{
889	$nodesWithStyleDisplayNone = $xPath->query(
890	'//*[contains(translate(translate(@style," ",""),"NOE","noe"),"display:none")]'
891	);
892	if ($nodesWithStyleDisplayNone->length === 0) {
893	return;
894	}
895
896	// The checks on parentNode and is_callable below ensure that if we've deleted the parent node,
897	// we don't try to call removeChild on a nonexistent child node
898	/** @var \DOMNode $node */
899	foreach ($nodesWithStyleDisplayNone as $node) {
900	if ($node->parentNode && is_callable([$node->parentNode, 'removeChild'])) {
901	$node->parentNode->removeChild($node);
902	}
903	}
904	}
905
906	/**
907	* Parses the document and normalizes all existing CSS attributes.
908	* This changes 'DISPLAY: none' to 'display: none'.
909	* We wouldn't have to do this if DOMXPath supported XPath 2.0.
910	* Also stores a reference of nodes with existing inline styles so we don't overwrite them.
911	*
912	* @param \DOMXPath $xPath
913	*
914	* @return void
915	*/
916	private function normalizeStyleAttributesOfAllNodes(\DOMXPath $xPath)
917	{
918	/** @var \DOMElement $node */
919	foreach ($this->getAllNodesWithStyleAttribute($xPath) as $node) {
920	if ($this->isInlineStyleAttributesParsingEnabled) {
921	$this->normalizeStyleAttributes($node);
922	}
923	// Remove style attribute in every case, so we can add them back (if inline style attributes
924	// parsing is enabled) to the end of the style list, thus keeping the right priority of CSS rules;
925	// else original inline style rules may remain at the beginning of the final inline style definition
926	// of a node, which may give not the desired results
927	$node->removeAttribute('style');
928	}
929	}
930
931	/**
932	* Normalizes the value of the "style" attribute and saves it.
933	*
934	* @param \DOMElement $node
935	*
936	* @return void
937	*/
938	private function normalizeStyleAttributes(\DOMElement $node)
939	{
940	$normalizedOriginalStyle = preg_replace_callback(
941	'/[A-z\\-]+(?=\\:)/S',
942	function (array $m) {
943	return strtolower($m[0]);
944	},
945	$node->getAttribute('style')
946	);
947
948	// in order to not overwrite existing style attributes in the HTML, we
949	// have to save the original HTML styles
950	$nodePath = $node->getNodePath();
951	if (!isset($this->styleAttributesForNodes[$nodePath])) {
952	$this->styleAttributesForNodes[$nodePath] = $this->parseCssDeclarationsBlock($normalizedOriginalStyle);
953	$this->visitedNodes[$nodePath] = $node;
954	}
955
956	$node->setAttribute('style', $normalizedOriginalStyle);
957	}
958
959	/**
960	* Merges styles from styles attributes and style nodes and applies them to the attribute nodes
961	*
962	* @return void
963	*/
964	private function fillStyleAttributesWithMergedStyles()
965	{
966	foreach ($this->styleAttributesForNodes as $nodePath => $styleAttributesForNode) {
967	$node = $this->visitedNodes[$nodePath];
968	$currentStyleAttributes = $this->parseCssDeclarationsBlock($node->getAttribute('style'));
969	$node->setAttribute(
970	'style',
971	$this->generateStyleStringFromDeclarationsArrays(
972	$currentStyleAttributes,
973	$styleAttributesForNode
974	)
975	);
976	}
977	}
978
979	/**
980	* This method merges old or existing name/value array with new name/value array
981	* and then generates a string of the combined style suitable for placing inline.
982	* This becomes the single point for CSS string generation allowing for consistent
983	* CSS output no matter where the CSS originally came from.
984	*
985	* @param string[] $oldStyles
986	* @param string[] $newStyles
987	*
988	* @return string
989	*/
990	private function generateStyleStringFromDeclarationsArrays(array $oldStyles, array $newStyles)
991	{
992	$combinedStyles = array_merge($oldStyles, $newStyles);
993	$cacheKey = serialize($combinedStyles);
994	if (isset($this->caches[self::CACHE_KEY_COMBINED_STYLES][$cacheKey])) {
995	return $this->caches[self::CACHE_KEY_COMBINED_STYLES][$cacheKey];
996	}
997
998	foreach ($oldStyles as $attributeName => $attributeValue) {
999	if (!isset($newStyles[$attributeName])) {
1000	continue;
1001	}
1002
1003	$newAttributeValue = $newStyles[$attributeName];
1004	if ($this->attributeValueIsImportant($attributeValue)
1005	&& !$this->attributeValueIsImportant($newAttributeValue)
1006	) {
1007	$combinedStyles[$attributeName] = $attributeValue;
1008	}
1009	}
1010
1011	$style = '';
1012	foreach ($combinedStyles as $attributeName => $attributeValue) {
1013	$style .= strtolower(trim($attributeName)) . ': ' . trim($attributeValue) . '; ';
1014	}
1015	$trimmedStyle = rtrim($style);
1016
1017	$this->caches[self::CACHE_KEY_COMBINED_STYLES][$cacheKey] = $trimmedStyle;
1018
1019	return $trimmedStyle;
1020	}
1021
1022	/**
1023	* Generates a CSS style string suitable to be used inline from the $styleDeclarations property => value array.
1024	*
1025	* @param string[] $styleDeclarations
1026	*
1027	* @return string
1028	*/
1029	private function generateStyleStringFromSingleDeclarationsArray(array $styleDeclarations)
1030	{
1031	return $this->generateStyleStringFromDeclarationsArrays([], $styleDeclarations);
1032	}
1033
1034	/**
1035	* Checks whether $attributeValue is marked as !important.
1036	*
1037	* @param string $attributeValue
1038	*
1039	* @return bool
1040	*/
1041	private function attributeValueIsImportant($attributeValue)
1042	{
1043	return strtolower(substr(trim($attributeValue), -10)) === '!important';
1044	}
1045
1046	/**
1047	* Applies $css to $xmlDocument, limited to the media queries that actually apply to the document.
1048	*
1049	* @param \DOMDocument $xmlDocument the document to match against
1050	* @param \DOMXPath $xPath
1051	* @param string $css a string of CSS
1052	*
1053	* @return void
1054	*/
1055	private function copyCssWithMediaToStyleNode(\DOMDocument $xmlDocument, \DOMXPath $xPath, $css)
1056	{
1057	if ($css === '') {
1058	return;
1059	}
1060
1061	$mediaQueriesRelevantForDocument = [];
1062
1063	foreach ($this->extractMediaQueriesFromCss($css) as $mediaQuery) {
1064	foreach ($this->parseCssRules($mediaQuery['css']) as $selector) {
1065	if ($this->existsMatchForCssSelector($xPath, $selector['selector'])) {
1066	$mediaQueriesRelevantForDocument[] = $mediaQuery['query'];
1067	break;
1068	}
1069	}
1070	}
1071
1072	$this->addStyleElementToDocument($xmlDocument, implode($mediaQueriesRelevantForDocument));
1073	}
1074
1075	/**
1076	* Extracts the media queries from $css while skipping empty media queries.
1077	*
1078	* @param string $css
1079	*
1080	* @return string[][] numeric array with string sub-arrays with the keys "css" and "query"
1081	*/
1082	private function extractMediaQueriesFromCss($css)
1083	{
1084	preg_match_all('/@media\\b[^{]({((?:[^{}]+\|(?1)))})/', $css, $rawMediaQueries, PREG_SET_ORDER);
1085	$parsedQueries = [];
1086
1087	/** @var string[][] $rawMediaQueries */
1088	foreach ($rawMediaQueries as $mediaQuery) {
1089	if ($mediaQuery[2] !== '') {
1090	$parsedQueries[] = [
1091	'css' => $mediaQuery[2],
1092	'query' => $mediaQuery[0],
1093	];
1094	}
1095	}
1096
1097	return $parsedQueries;
1098	}
1099
1100	/**
1101	* Checks whether there is at least one matching element for $cssSelector.
1102	* When not in debug mode, it returns true also for invalid selectors (because they may be valid,
1103	* just not implemented/recognized yet by Emogrifier).
1104	*
1105	* @param \DOMXPath $xPath
1106	* @param string $cssSelector
1107	*
1108	* @return bool
1109	*
1110	* @throws \InvalidArgumentException
1111	*/
1112	private function existsMatchForCssSelector(\DOMXPath $xPath, $cssSelector)
1113	{
1114	try {
1115	$nodesMatchingSelector = $xPath->query($this->translateCssToXpath($cssSelector));
1116	} catch (\InvalidArgumentException $e) {
1117	if ($this->debug) {
1118	throw $e;
1119	}
1120	return true;
1121	}
1122
1123	return $nodesMatchingSelector !== false && $nodesMatchingSelector->length !== 0;
1124	}
1125
1126	/**
1127	* Returns CSS content.
1128	*
1129	* @param \DOMXPath $xPath
1130	*
1131	* @return string
1132	*/
1133	private function getCssFromAllStyleNodes(\DOMXPath $xPath)
1134	{
1135	$styleNodes = $xPath->query('//style');
1136
1137	if ($styleNodes === false) {
1138	return '';
1139	}
1140
1141	$css = '';
1142	/** @var \DOMNode $styleNode */
1143	foreach ($styleNodes as $styleNode) {
1144	$css .= "\n\n" . $styleNode->nodeValue;
1145	$styleNode->parentNode->removeChild($styleNode);
1146	}
1147
1148	return $css;
1149	}
1150
1151	/**
1152	* Adds a style element with $css to $document head.
1153	*
1154	* This method is protected to allow overriding.
1155	*
1156	*
1157	* @param \DOMDocument $document
1158	* @param string $css
1159	*
1160	* @return void
1161	*/
1162	protected function addStyleElementToDocument(\DOMDocument $document, $css)
1163	{
1164	$styleElement = $document->createElement('style', $css);
1165	$styleAttribute = $document->createAttribute('type');
1166	$styleAttribute->value = 'text/css';
1167	$styleElement->appendChild($styleAttribute);
1168
1169	$headElement = $this->getHeadElement($document);
1170	$headElement->appendChild($styleElement);
1171	}
1172
1173	/**
1174	* Checks that $document has a BODY element and adds it if it is missing.
1175	*
1176	* @param \DOMDocument $document
1177	*/
1178	private function ensureExistenceOfBodyElement(\DOMDocument $document)
1179	{
1180	if ($document->getElementsByTagName('body')->item(0) !== null) {
1181	return;
1182	}
1183
1184	$htmlElement = $document->getElementsByTagName('html')->item(0);
1185
1186	$htmlElement->appendChild($document->createElement('body'));
1187	}
1188
1189	/**
1190	* Returns the BODY element.
1191	*
1192	* This method assumes that there always is a BODY element.
1193	*
1194	* @param \DOMDocument $document
1195	*
1196	* @return \DOMElement
1197	*
1198	* @throws \BadMethodCallException
1199	*/
1200	private function getBodyElement(\DOMDocument $document)
1201	{
1202	$bodyElement = $document->getElementsByTagName('body')->item(0);
1203	if ($bodyElement === null) {
1204	throw new \BadMethodCallException(
1205	'getBodyElement method may only be called after ensureExistenceOfBodyElement has been called.',
1206	1508173775427
1207	);
1208	}
1209
1210	return $bodyElement;
1211	}
1212
1213	/**
1214	* Returns the BODY element.
1215	*
1216	* This method assumes that there always is a BODY element.
1217	*
1218	* @param \DOMDocument $document
1219	*
1220	* @return \DOMElement
1221	*
1222	* @throws \BadMethodCallException
1223	*/
1224	private function getHeadElement(\DOMDocument $document)
1225	{
1226	$headElement = $document->getElementsByTagName('head')->item(0);
1227	if ($headElement === null) {
1228	throw new \BadMethodCallException(
1229	'getHeadElement method may only be called after ensureExistenceOfBodyElement has been called.',
1230	1508173775427
1231	);
1232	}
1233
1234	return $headElement;
1235	}
1236
1237	/**
1238	* Splits input CSS code to an array where:
1239	*
1240	* - key "css" will be contains clean CSS code
1241	* - key "media" will be contains all valuable media queries
1242	*
1243	* Example:
1244	*
1245	* The CSS code
1246	*
1247	* "@import "file.css"; h1 { color:red; } @media { h1 {}} @media tv { h1 {}}"
1248	*
1249	* will be parsed into the following array:
1250	*
1251	* "css" => "h1 { color:red; }"
1252	* "media" => "@media { h1 {}}"
1253	*
1254	* @param string $css
1255	*
1256	* @return string[]
1257	*/
1258	private function splitCssAndMediaQuery($css)
1259	{
1260	$cssWithoutComments = preg_replace('/\\/\\.\\*\\//sU', '', $css);
1261
1262	$mediaTypesExpression = '';
1263	if (!empty($this->allowedMediaTypes)) {
1264	$mediaTypesExpression = '\|' . implode('\|', array_keys($this->allowedMediaTypes));
1265	}
1266
1267	$media = '';
1268	$cssForAllowedMediaTypes = preg_replace_callback(
1269	'#@media\\s+(?:only\\s)?(?:[\\s{\\(]\\s' . $mediaTypesExpression . ')\\s[^{]+{.}\\s}\\s#misU',
1270	function ($matches) use (&$media) {
1271	$media .= $matches[0];
1272	},
1273	$cssWithoutComments
1274	);
1275
1276	// filter the CSS
1277	$search = [
1278	'import directives' => '/^\\s*@import\\s[^;]+;/misU',
1279	'remaining media enclosures' => '/^\\s@media\\s[^{]+{(.)}\\s*}\\s/misU',
1280	];
1281
1282	$cleanedCss = preg_replace($search, '', $cssForAllowedMediaTypes);
1283
1284	return ['css' => $cleanedCss, 'media' => $media];
1285	}
1286
1287	/**
1288	* Creates a DOMDocument instance with the current HTML.
1289	*
1290	* @return \DOMDocument
1291	*/
1292	private function createRawXmlDocument()
1293	{
1294	$xmlDocument = new \DOMDocument;
1295	$xmlDocument->encoding = 'UTF-8';
1296	$xmlDocument->strictErrorChecking = false;
1297	$xmlDocument->formatOutput = true;
1298	$libXmlState = libxml_use_internal_errors(true);
1299	$xmlDocument->loadHTML($this->getUnifiedHtml());
1300	libxml_clear_errors();
1301	libxml_use_internal_errors($libXmlState);
1302	$xmlDocument->normalizeDocument();
1303
1304	return $xmlDocument;
1305	}
1306
1307	/**
1308	* Returns the HTML with the unprocessable HTML tags removed and
1309	* with added document type and Content-Type meta tag if needed.
1310	*
1311	* @return string the unified HTML
1312	*
1313	* @throws \BadMethodCallException
1314	*/
1315	private function getUnifiedHtml()
1316	{
1317	$htmlWithoutUnprocessableTags = $this->removeUnprocessableTags($this->html);
1318	$htmlWithDocumentType = $this->ensureDocumentType($htmlWithoutUnprocessableTags);
1319
1320	return $this->addContentTypeMetaTag($htmlWithDocumentType);
1321	}
1322
1323	/**
1324	* Removes the unprocessable tags from $html (if this feature is enabled).
1325	*
1326	* @param string $html
1327	*
1328	* @return string the reworked HTML with the unprocessable tags removed
1329	*/
1330	private function removeUnprocessableTags($html)
1331	{
1332	if (empty($this->unprocessableHtmlTags)) {
1333	return $html;
1334	}
1335
1336	$unprocessableHtmlTags = implode('\|', $this->unprocessableHtmlTags);
1337
1338	return preg_replace(
1339	'/<\\/?(' . $unprocessableHtmlTags . ')[^>]*>/i',
1340	'',
1341	$html
1342	);
1343	}
1344
1345	/**
1346	* Makes sure that the passed HTML has a document type.
1347	*
1348	* @param string $html
1349	*
1350	* @return string HTML with document type
1351	*/
1352	private function ensureDocumentType($html)
1353	{
1354	$hasDocumentType = stripos($html, '<!DOCTYPE') !== false;
1355	if ($hasDocumentType) {
1356	return $html;
1357	}
1358
1359	return self::DEFAULT_DOCUMENT_TYPE . $html;
1360	}
1361
1362	/**
1363	* Adds a Content-Type meta tag for the charset.
1364	*
1365	* @param string $html
1366	*
1367	* @return string the HTML with the meta tag added
1368	*/
1369	private function addContentTypeMetaTag($html)
1370	{
1371	$hasContentTypeMetaTag = stripos($html, 'Content-Type') !== false;
1372	if ($hasContentTypeMetaTag) {
1373	return $html;
1374	}
1375
1376	// We are trying to insert the meta tag to the right spot in the DOM.
1377	// If we just prepended it to the HTML, we would lose attributes set to the HTML tag.
1378	$hasHeadTag = stripos($html, '<head') !== false;
1379	$hasHtmlTag = stripos($html, '<html') !== false;
1380
1381	if ($hasHeadTag) {
1382	$reworkedHtml = preg_replace('/<head(.*?)>/i', '<head$1>' . self::CONTENT_TYPE_META_TAG, $html);
1383	} elseif ($hasHtmlTag) {
1384	$reworkedHtml = preg_replace(
1385	'/<html(.*?)>/i',
1386	'<html$1><head>' . self::CONTENT_TYPE_META_TAG . '</head>',
1387	$html
1388	);
1389	} else {
1390	$reworkedHtml = self::CONTENT_TYPE_META_TAG . $html;
1391	}
1392
1393	return $reworkedHtml;
1394	}
1395
1396	/**
1397	* @param string[] $a
1398	* @param string[] $b
1399	*
1400	* @return int
1401	*/
1402	private function sortBySelectorPrecedence(array $a, array $b)
1403	{
1404	$precedenceA = $this->getCssSelectorPrecedence($a['selector']);
1405	$precedenceB = $this->getCssSelectorPrecedence($b['selector']);
1406
1407	// We want these sorted in ascending order so selectors with lesser precedence get processed first and
1408	// selectors with greater precedence get sorted last.
1409	$precedenceForEquals = ($a['line'] < $b['line'] ? -1 : 1);
1410	$precedenceForNotEquals = ($precedenceA < $precedenceB ? -1 : 1);
1411	return ($precedenceA === $precedenceB) ? $precedenceForEquals : $precedenceForNotEquals;
1412	}
1413
1414	/**
1415	* @param string $selector
1416	*
1417	* @return int
1418	*/
1419	private function getCssSelectorPrecedence($selector)
1420	{
1421	$selectorKey = md5($selector);
1422	if (!isset($this->caches[self::CACHE_KEY_SELECTOR][$selectorKey])) {
1423	$precedence = 0;
1424	$value = 100;
1425	// ids: worth 100, classes: worth 10, elements: worth 1
1426	$search = ['\\#', '\\.', ''];
1427
1428	foreach ($search as $s) {
1429	if (trim($selector) === '') {
1430	break;
1431	}
1432	$number = 0;
1433	$selector = preg_replace('/' . $s . '\\w+/', '', $selector, -1, $number);
1434	$precedence += ($value * $number);
1435	$value /= 10;
1436	}
1437	$this->caches[self::CACHE_KEY_SELECTOR][$selectorKey] = $precedence;
1438	}
1439
1440	return $this->caches[self::CACHE_KEY_SELECTOR][$selectorKey];
1441	}
1442
1443	/**
1444	* Maps a CSS selector to an XPath query string.
1445	*
1446	* @see http://plasmasturm.org/log/444/
1447	*
1448	* @param string $cssSelector a CSS selector
1449	*
1450	* @return string the corresponding XPath selector
1451	*/
1452	private function translateCssToXpath($cssSelector)
1453	{
1454	$paddedSelector = ' ' . $cssSelector . ' ';
1455	$lowercasePaddedSelector = preg_replace_callback(
1456	'/\\s+\\w+\\s+/',
1457	function (array $matches) {
1458	return strtolower($matches[0]);
1459	},
1460	$paddedSelector
1461	);
1462	$trimmedLowercaseSelector = trim($lowercasePaddedSelector);
1463	$xPathKey = md5($trimmedLowercaseSelector);
1464	if (isset($this->caches[self::CACHE_KEY_XPATH][$xPathKey])) {
1465	return $this->caches[self::CACHE_KEY_SELECTOR][$xPathKey];
1466	}
1467
1468	$hasNotSelector = (bool)preg_match(
1469	'/^([^:]+):not\$\\s([[:ascii:]]+)\\s\$$/',
1470	$trimmedLowercaseSelector,
1471	$matches
1472	);
1473	if (!$hasNotSelector) {
1474	$xPath = '//' . $this->translateCssToXpathPass($trimmedLowercaseSelector);
1475	} else {
1476	/** @var string[] $matches */
1477	$partBeforeNot = $matches[1];
1478	$notContents = $matches[2];
1479	$xPath = '//' . $this->translateCssToXpathPass($partBeforeNot) .
1480	'[not(' . $this->translateCssToXpathPassInline($notContents) . ')]';
1481	}
1482	$this->caches[self::CACHE_KEY_SELECTOR][$xPathKey] = $xPath;
1483
1484	return $this->caches[self::CACHE_KEY_SELECTOR][$xPathKey];
1485	}
1486
1487	/**
1488	* Flexibly translates the CSS selector $trimmedLowercaseSelector to an xPath selector.
1489	*
1490	* @param string $trimmedLowercaseSelector
1491	*
1492	* @return string
1493	*/
1494	private function translateCssToXpathPass($trimmedLowercaseSelector)
1495	{
1496	return $this->translateCssToXpathPassWithMatchClassAttributesCallback(
1497	$trimmedLowercaseSelector,
1498	[$this, 'matchClassAttributes']
1499	);
1500	}
1501
1502	/**
1503	* Flexibly translates the CSS selector $trimmedLowercaseSelector to an xPath selector for inline usage.
1504	*
1505	* @param string $trimmedLowercaseSelector
1506	*
1507	* @return string
1508	*/
1509	private function translateCssToXpathPassInline($trimmedLowercaseSelector)
1510	{
1511	return $this->translateCssToXpathPassWithMatchClassAttributesCallback(
1512	$trimmedLowercaseSelector,
1513	[$this, 'matchClassAttributesInline']
1514	);
1515	}
1516
1517	/**
1518	* Flexibly translates the CSS selector $trimmedLowercaseSelector to an xPath selector while using
1519	* $matchClassAttributesCallback as to match the class attributes.
1520	*
1521	* @param string $trimmedLowercaseSelector
1522	* @param callable $matchClassAttributesCallback
1523	*
1524	* @return string
1525	*/
1526	private function translateCssToXpathPassWithMatchClassAttributesCallback(
1527	$trimmedLowercaseSelector,
1528	callable $matchClassAttributesCallback
1529	) {
1530	$roughXpath = preg_replace(array_keys($this->xPathRules), $this->xPathRules, $trimmedLowercaseSelector);
1531	$xPathWithIdAttributeMatchers = preg_replace_callback(
1532	self::ID_ATTRIBUTE_MATCHER,
1533	[$this, 'matchIdAttributes'],
1534	$roughXpath
1535	);
1536	$xPathWithIdAttributeAndClassMatchers = preg_replace_callback(
1537	self::CLASS_ATTRIBUTE_MATCHER,
1538	$matchClassAttributesCallback,
1539	$xPathWithIdAttributeMatchers
1540	);
1541
1542	// Advanced selectors are going to require a bit more advanced emogrification.
1543	$xPathWithIdAttributeAndClassMatchers = preg_replace_callback(
1544	'/([^\\/]+):nth-child\$\\s(odd\|even\|[+\\-]?\\d\|[+\\-]?\\d?n(\\s[+\\-]\\s\\d)?)\\s\$/i',
1545	[$this, 'translateNthChild'],
1546	$xPathWithIdAttributeAndClassMatchers
1547	);
1548	$finalXpath = preg_replace_callback(
1549	'/([^\\/]+):nth-of-type\$\s(odd\|even\|[+\\-]?\\d\|[+\\-]?\\d?n(\\s[+\\-]\\s\\d)?)\\s\$/i',
1550	[$this, 'translateNthOfType'],
1551	$xPathWithIdAttributeAndClassMatchers
1552	);
1553
1554	return $finalXpath;
1555	}
1556
1557	/**
1558	* @param string[] $match
1559	*
1560	* @return string
1561	*/
1562	private function matchIdAttributes(array $match)
1563	{
1564	return ($match[1] !== '' ? $match[1] : '*') . '[@id="' . $match[2] . '"]';
1565	}
1566
1567	/**
1568	* @param string[] $match
1569	*
1570	* @return string xPath class attribute query wrapped in element selector
1571	*/
1572	private function matchClassAttributes(array $match)
1573	{
1574	return ($match[1] !== '' ? $match[1] : '*') . '[' . $this->matchClassAttributesInline($match) . ']';
1575	}
1576
1577	/**
1578	* @param string[] $match
1579	*
1580	* @return string xPath class attribute query
1581	*/
1582	private function matchClassAttributesInline(array $match)
1583	{
1584	return 'contains(concat(" ",@class," "),concat(" ","' .
1585	implode(
1586	'"," "))][contains(concat(" ",@class," "),concat(" ","',
1587	explode('.', substr($match[2], 1))
1588	) . '"," "))';
1589	}
1590
1591	/**
1592	* @param string[] $match
1593	*
1594	* @return string
1595	*/
1596	private function translateNthChild(array $match)
1597	{
1598	$parseResult = $this->parseNth($match);
1599
1600	if (isset($parseResult[self::MULTIPLIER])) {
1601	if ($parseResult[self::MULTIPLIER] < 0) {
1602	$parseResult[self::MULTIPLIER] = abs($parseResult[self::MULTIPLIER]);
1603	$xPathExpression = sprintf(
1604	'*[(last() - position()) mod %1%u = %2$u]/self::%3$s',
1605	$parseResult[self::MULTIPLIER],
1606	$parseResult[self::INDEX],
1607	$match[1]
1608	);
1609	} else {
1610	$xPathExpression = sprintf(
1611	'*[position() mod %1$u = %2$u]/self::%3$s',
1612	$parseResult[self::MULTIPLIER],
1613	$parseResult[self::INDEX],
1614	$match[1]
1615	);
1616	}
1617	} else {
1618	$xPathExpression = sprintf('*[%1$u]/self::%2$s', $parseResult[self::INDEX], $match[1]);
1619	}
1620
1621	return $xPathExpression;
1622	}
1623
1624	/**
1625	* @param string[] $match
1626	*
1627	* @return string
1628	*/
1629	private function translateNthOfType(array $match)
1630	{
1631	$parseResult = $this->parseNth($match);
1632
1633	if (isset($parseResult[self::MULTIPLIER])) {
1634	if ($parseResult[self::MULTIPLIER] < 0) {
1635	$parseResult[self::MULTIPLIER] = abs($parseResult[self::MULTIPLIER]);
1636	$xPathExpression = sprintf(
1637	'%1$s[(last() - position()) mod %2$u = %3$u]',
1638	$match[1],
1639	$parseResult[self::MULTIPLIER],
1640	$parseResult[self::INDEX]
1641	);
1642	} else {
1643	$xPathExpression = sprintf(
1644	'%1$s[position() mod %2$u = %3$u]',
1645	$match[1],
1646	$parseResult[self::MULTIPLIER],
1647	$parseResult[self::INDEX]
1648	);
1649	}
1650	} else {
1651	$xPathExpression = sprintf('%1$s[%2$u]', $match[1], $parseResult[self::INDEX]);
1652	}
1653
1654	return $xPathExpression;
1655	}
1656
1657	/**
1658	* @param string[] $match
1659	*
1660	* @return int[]
1661	*/
1662	private function parseNth(array $match)
1663	{
1664	if (in_array(strtolower($match[2]), ['even', 'odd'], true)) {
1665	// we have "even" or "odd"
1666	$index = strtolower($match[2]) === 'even' ? 0 : 1;
1667	return [self::MULTIPLIER => 2, self::INDEX => $index];
1668	}
1669	if (stripos($match[2], 'n') === false) {
1670	// if there is a multiplier
1671	$index = (int)str_replace(' ', '', $match[2]);
1672	return [self::INDEX => $index];
1673	}
1674
1675	if (isset($match[3])) {
1676	$multipleTerm = str_replace($match[3], '', $match[2]);
1677	$index = (int)str_replace(' ', '', $match[3]);
1678	} else {
1679	$multipleTerm = $match[2];
1680	$index = 0;
1681	}
1682
1683	$multiplier = str_ireplace('n', '', $multipleTerm);
1684
1685	if ($multiplier === '') {
1686	$multiplier = 1;
1687	} elseif ($multiplier === '0') {
1688	return [self::INDEX => $index];
1689	} else {
1690	$multiplier = (int)$multiplier;
1691	}
1692
1693	while ($index < 0) {
1694	$index += abs($multiplier);
1695	}
1696
1697	return [self::MULTIPLIER => $multiplier, self::INDEX => $index];
1698	}
1699
1700	/**
1701	* Parses a CSS declaration block into property name/value pairs.
1702	*
1703	* Example:
1704	*
1705	* The declaration block
1706	*
1707	* "color: #000; font-weight: bold;"
1708	*
1709	* will be parsed into the following array:
1710	*
1711	* "color" => "#000"
1712	* "font-weight" => "bold"
1713	*
1714	* @param string $cssDeclarationsBlock the CSS declarations block without the curly braces, may be empty
1715	*
1716	* @return string[]
1717	* the CSS declarations with the property names as array keys and the property values as array values
1718	*/
1719	private function parseCssDeclarationsBlock($cssDeclarationsBlock)
1720	{
1721	if (isset($this->caches[self::CACHE_KEY_CSS_DECLARATIONS_BLOCK][$cssDeclarationsBlock])) {
1722	return $this->caches[self::CACHE_KEY_CSS_DECLARATIONS_BLOCK][$cssDeclarationsBlock];
1723	}
1724
1725	$properties = [];
1726	$declarations = preg_split('/;(?!base64\|charset)/', $cssDeclarationsBlock);
1727
1728	foreach ($declarations as $declaration) {
1729	$matches = [];
1730	if (!preg_match('/^([A-Za-z\\-]+)\\s:\\s(.+)$/', trim($declaration), $matches)) {
1731	continue;
1732	}
1733
1734	$propertyName = strtolower($matches[1]);
1735	$propertyValue = $matches[2];
1736	$properties[$propertyName] = $propertyValue;
1737	}
1738	$this->caches[self::CACHE_KEY_CSS_DECLARATIONS_BLOCK][$cssDeclarationsBlock] = $properties;
1739
1740	return $properties;
1741	}
1742
1743	/**
1744	* Find the nodes that are not to be emogrified.
1745	*
1746	* @param \DOMXPath $xPath
1747	*
1748	* @return \DOMElement[]
1749	*
1750	* @throws \InvalidArgumentException
1751	*/
1752	private function getNodesToExclude(\DOMXPath $xPath)
1753	{
1754	$excludedNodes = [];
1755	foreach (array_keys($this->excludedSelectors) as $selectorToExclude) {
1756	try {
1757	$matchingNodes = $xPath->query($this->translateCssToXpath($selectorToExclude));
1758	} catch (\InvalidArgumentException $e) {
1759	if ($this->debug) {
1760	throw $e;
1761	}
1762	continue;
1763	}
1764	foreach ($matchingNodes as $node) {
1765	$excludedNodes[] = $node;
1766	}
1767	}
1768
1769	return $excludedNodes;
1770	}
1771
1772	/**
1773	* Handles invalid xPath expression warnings, generated during the process() method,
1774	* during querying \DOMDocument and trigger \InvalidArgumentException with invalid selector
1775	* or \RuntimeException, depending on the source of the warning.
1776	*
1777	* @param int $type
1778	* @param string $message
1779	* @param string $file
1780	* @param int $line
1781	* @param array $context
1782	*
1783	* @return bool always false
1784	*
1785	* @throws \InvalidArgumentException
1786	* @throws \RuntimeException
1787	*/
1788	public function handleXpathQueryWarnings( // @codingStandardsIgnoreLine
1789	$type,
1790	$message,
1791	$file,
1792	$line,
1793	array $context
1794	) {
1795	$selector = '';
1796	if (isset($context['cssRule']['selector'])) {
1797	// warnings generated by invalid/unrecognized selectors in method process()
1798	$selector = $context['cssRule']['selector'];
1799	} elseif (isset($context['selectorToExclude'])) {
1800	// warnings generated by invalid/unrecognized selectors in method getNodesToExclude()
1801	$selector = $context['selectorToExclude'];
1802	} elseif (isset($context['cssSelector'])) {
1803	// warnings generated by invalid/unrecognized selectors in method existsMatchForCssSelector()
1804	$selector = $context['cssSelector'];
1805	}
1806
1807	if ($selector !== '') {
1808	throw new \InvalidArgumentException(
1809	sprintf(
1810	'%1$s in selector >> %2$s << in %3$s on line %4$u',
1811	esc_html($message),
1812	esc_html($selector),
1813	esc_html($file),
1814	(int) $line
1815	),
1816	1509279985
1817	);
1818	}
1819
1820	// Catches eventual warnings generated by method getAllNodesWithStyleAttribute()
1821	if (isset($context['xPath'])) {
1822	throw new \RuntimeException(
1823	sprintf(
1824	'%1$s in %2$s on line %3$u',
1825	esc_html($message),
1826	esc_html($file),
1827	(int) $line
1828	),
1829	1509280067
1830	);
1831	}
1832
1833	// the normal error handling continues when handler return false
1834	return false;
1835	}
1836
1837	/**
1838	* Sets the debug mode.
1839	*
1840	* @param bool $debug set to true to enable debug mode
1841	*
1842	* @return void
1843	*/
1844	public function setDebug($debug)
1845	{
1846	$this->debug = $debug;
1847	}
1848	}
1849