learnpress / vendor / tijsverkoyen / css-to-inline-styles / src / CssToInlineStyles.php

CssToInlineStyles.php in LearnPress – WordPress LMS Plugin for Create and Sell Online Courses 4.4.10, at vendor/tijsverkoyen/css-to-inline-styles/src/CssToInlineStyles.php

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1	<?php
2
3	namespace TijsVerkoyen\CssToInlineStyles;
4
5	use Symfony\Component\CssSelector\CssSelectorConverter;
6	use Symfony\Component\CssSelector\Exception\ExceptionInterface;
7	use TijsVerkoyen\CssToInlineStyles\Css\Processor;
8	use TijsVerkoyen\CssToInlineStyles\Css\Property\Processor as PropertyProcessor;
9	use TijsVerkoyen\CssToInlineStyles\Css\Property\Property;
10	use TijsVerkoyen\CssToInlineStyles\Css\Rule\Processor as RuleProcessor;
11
12	class CssToInlineStyles
13	{
14	/**
15	* @var CssSelectorConverter
16	*/
17	private $cssConverter;
18
19	public function __construct()
20	{
21	$this->cssConverter = new CssSelectorConverter();
22	}
23
24	/**
25	* Will inline the $css into the given $html
26	*
27	* Remark: if the html contains <style>-tags those will be used, the rules
28	* in $css will be appended.
29	*
30	* @param string $html
31	* @param string $css
32	*
33	* @return string
34	*/
35	public function convert($html, $css = null)
36	{
37	$document = $this->createDomDocumentFromHtml($html);
38	$processor = new Processor();
39
40	// get all styles from the style-tags
41	$rules = $processor->getRules(
42	$processor->getCssFromStyleTags($html)
43	);
44
45	if ($css !== null) {
46	$rules = $processor->getRules($css, $rules);
47	}
48
49	$document = $this->inline($document, $rules);
50
51	return $this->getHtmlFromDocument($document);
52	}
53
54	/**
55	* Inline the given properties on a given DOMElement
56	*
57	* @param \DOMElement $element
58	* @param Property[] $properties
59	*
60	* @return \DOMElement
61	*/
62	public function inlineCssOnElement(\DOMElement $element, array $properties)
63	{
64	if (empty($properties)) {
65	return $element;
66	}
67
68	$cssProperties = array();
69	$inlineProperties = array();
70
71	foreach ($this->getInlineStyles($element) as $property) {
72	$inlineProperties[$property->getName()] = $property;
73	}
74
75	foreach ($properties as $property) {
76	if (!isset($inlineProperties[$property->getName()])) {
77	$cssProperties[$property->getName()] = $property;
78	}
79	}
80
81	$rules = array();
82	foreach (array_merge($cssProperties, $inlineProperties) as $property) {
83	$rules[] = $property->toString();
84	}
85	$element->setAttribute('style', implode(' ', $rules));
86
87	return $element;
88	}
89
90	/**
91	* Get the current inline styles for a given DOMElement
92	*
93	* @param \DOMElement $element
94	*
95	* @return Property[]
96	*/
97	public function getInlineStyles(\DOMElement $element)
98	{
99	$processor = new PropertyProcessor();
100
101	return $processor->convertArrayToObjects(
102	$processor->splitIntoSeparateProperties(
103	$element->getAttribute('style')
104	)
105	);
106	}
107
108	/**
109	* @param string $html
110	*
111	* @return \DOMDocument
112	*/
113	protected function createDomDocumentFromHtml($html)
114	{
115	$document = new \DOMDocument('1.0', 'UTF-8');
116	$internalErrors = libxml_use_internal_errors(true);
117	$document->loadHTML(mb_encode_numericentity($html, [0x80, 0x10FFFF, 0, 0x1FFFFF], 'UTF-8'));
118	libxml_use_internal_errors($internalErrors);
119	$document->formatOutput = true;
120
121	return $document;
122	}
123
124	/**
125	* @param \DOMDocument $document
126	*
127	* @return string
128	*/
129	protected function getHtmlFromDocument(\DOMDocument $document)
130	{
131	// retrieve the document element
132	// we do it this way to preserve the utf-8 encoding
133	$htmlElement = $document->documentElement;
134
135	if ($htmlElement === null) {
136	throw new \RuntimeException('Failed to get HTML from empty document.');
137	}
138
139	$html = $document->saveHTML($htmlElement);
140
141	if ($html === false) {
142	throw new \RuntimeException('Failed to get HTML from document.');
143	}
144
145	$html = trim($html);
146
147	// retrieve the doctype
148	$document->removeChild($htmlElement);
149	$doctype = $document->saveHTML();
150	if ($doctype === false) {
151	$doctype = '';
152	}
153	$doctype = trim($doctype);
154
155	// if it is the html5 doctype convert it to lowercase
156	if ($doctype === '<!DOCTYPE html>') {
157	$doctype = strtolower($doctype);
158	}
159
160	return $doctype."\n".$html;
161	}
162
163	/**
164	* @param \DOMDocument $document
165	* @param Css\Rule\Rule[] $rules
166	*
167	* @return \DOMDocument
168	*/
169	protected function inline(\DOMDocument $document, array $rules)
170	{
171	if (empty($rules)) {
172	return $document;
173	}
174
175	/** @var \SplObjectStorage<\DOMElement, array<string, Property>> $propertyStorage */
176	$propertyStorage = new \SplObjectStorage();
177
178	$xPath = new \DOMXPath($document);
179
180	usort($rules, array(RuleProcessor::class, 'sortOnSpecificity'));
181
182	foreach ($rules as $rule) {
183	try {
184	$expression = $this->cssConverter->toXPath($rule->getSelector());
185	} catch (ExceptionInterface $e) {
186	continue;
187	}
188
189	$elements = $xPath->query($expression);
190
191	if ($elements === false) {
192	continue;
193	}
194
195	foreach ($elements as $element) {
196	\assert($element instanceof \DOMElement);
197	$propertyStorage[$element] = $this->calculatePropertiesToBeApplied(
198	$rule->getProperties(),
199	$propertyStorage->offsetExists($element) ? $propertyStorage[$element] : array()
200	);
201	}
202	}
203
204	foreach ($propertyStorage as $element) {
205	$this->inlineCssOnElement($element, $propertyStorage[$element]);
206	}
207
208	return $document;
209	}
210
211	/**
212	* Merge the CSS rules to determine the applied properties.
213	*
214	* @param Property[] $properties
215	* @param array<string, Property> $cssProperties existing applied properties indexed by name
216	*
217	* @return array<string, Property> updated properties, indexed by name
218	*/
219	private function calculatePropertiesToBeApplied(array $properties, array $cssProperties): array
220	{
221	if (empty($properties)) {
222	return $cssProperties;
223	}
224
225	foreach ($properties as $property) {
226	if (isset($cssProperties[$property->getName()])) {
227	$existingProperty = $cssProperties[$property->getName()];
228
229	//skip check to overrule if existing property is important and current is not
230	if ($existingProperty->isImportant() && !$property->isImportant()) {
231	continue;
232	}
233
234	//overrule if current property is important and existing is not, else check specificity
235	$overrule = !$existingProperty->isImportant() && $property->isImportant();
236	if (!$overrule) {
237	\assert($existingProperty->getOriginalSpecificity() !== null, 'Properties created for parsed CSS always have their associated specificity.');
238	\assert($property->getOriginalSpecificity() !== null, 'Properties created for parsed CSS always have their associated specificity.');
239	$overrule = $existingProperty->getOriginalSpecificity()->compareTo($property->getOriginalSpecificity()) <= 0;
240	}
241
242	if ($overrule) {
243	unset($cssProperties[$property->getName()]);
244	$cssProperties[$property->getName()] = $property;
245	}
246	} else {
247	$cssProperties[$property->getName()] = $property;
248	}
249	}
250
251	return $cssProperties;
252	}
253	}
254