19446892823

Committed 17 Nov 2025 10:35PM UTC coverage: 96.425% (-0.09%) from 96.518%

Build # 19446892823

Build Type

push

github

Committed by

web-flow

Commit Message

[TASK] Use safe preg functions in `CssVariableEvaluator` (#1503)

Part of #919

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98.46

/src/HtmlProcessor/CssVariableEvaluator.php

<?php

declare(strict_types=1);

namespace Pelago\Emogrifier\HtmlProcessor;

use Pelago\Emogrifier\Utilities\DeclarationBlockParser;

use function Safe\preg_match;
use function Safe\preg_replace_callback;

/**
 * This class can evaluate CSS custom properties that are defined and used in inline style attributes.
 */
final class CssVariableEvaluator extends AbstractHtmlProcessor
{
    /**
     * temporary collection used by {@see replaceVariablesInDeclarations} and callee methods
     *
     * @var array<non-empty-string, string>
     */
    private $currentVariableDefinitions = [];

    /**
     * Replaces all CSS custom property references in inline style attributes with their corresponding values where
     * defined in inline style attributes (either from the element itself or the nearest ancestor).
     *
     * @return $this
     *
     * @throws \UnexpectedValueException
     */
    public function evaluateVariables(): self
    {
        return $this->evaluateVariablesInElementAndDescendants($this->getHtmlElement(), []);
    }

    /**
     * @param array<non-empty-string, string> $declarations
     *
     * @return array<non-empty-string, string>
     */
    private function getVariableDefinitionsFromDeclarations(array $declarations): array
    {
        return \array_filter(
            $declarations,
            static function (string $key): bool {
                return \substr($key, 0, 2) === '--';
            },
            ARRAY_FILTER_USE_KEY
        );
    }

    /**
     * Callback function for {@see replaceVariablesInPropertyValue} performing regular expression replacement.
     *
     * @param array<int, string> $matches
     */
    private function getPropertyValueReplacement(array $matches): string
    {
        $variableName = $matches[1];

        if (isset($this->currentVariableDefinitions[$variableName])) {
            $variableValue = $this->currentVariableDefinitions[$variableName];
        } else {
            $fallbackValueSeparator = $matches[2] ?? '';
            if ($fallbackValueSeparator !== '') {
                $fallbackValue = $matches[3];
                // The fallback value may use other CSS variables, so recurse
                $variableValue = $this->replaceVariablesInPropertyValue($fallbackValue);
            } else {
                $variableValue = $matches[0];
            }
        }

        return $variableValue;
    }

    /**
     * Regular expression based on {@see https://stackoverflow.com/a/54143883/2511031 a StackOverflow answer}.
     */
    private function replaceVariablesInPropertyValue(string $propertyValue): string
    {
        $pattern = '/
                var\\(
                    \\s*+
                    # capture variable name including `--` prefix
                    (
                        --[^\\s\\),]++
                    )
                    \\s*+
                    # capture optional fallback value
                    (?:
                        # capture separator to confirm there is a fallback value
                        (,)\\s*
                        # begin capture with named group that can be used recursively
                        (?<recursable>
                            # begin named group to match sequence without parentheses, except in strings
                            (?<noparentheses>
                                # repeated zero or more times:
                                (?:
                                    # sequence without parentheses or quotes
                                    [^\\(\\)\'"]++
                                    |
                                    # string in double quotes
                                    "(?>[^"\\\\]++|\\\\.)*"
                                    |
                                    # string in single quotes
                                    \'(?>[^\'\\\\]++|\\\\.)*\'
                                )*+
                            )
                            # repeated zero or more times:
                            (?:
                                # sequence in parentheses
                                \\(
                                    # using the named recursable pattern
                                    (?&recursable)
                                \\)
                                # sequence without parentheses, except in strings
                                (?&noparentheses)
                            )*+
                        )
                    )?+
                \\)
            /x';

        $callable = \Closure::fromCallable([$this, 'getPropertyValueReplacement']);
        // The safe version is only available in "thecodingmachine/safe" for PHP >= 8.1.
        if (\function_exists('Safe\\preg_replace_callback')) {
            $result = preg_replace_callback($pattern, $callable, $propertyValue);
        } else {
            $result = \preg_replace_callback($pattern, $callable, $propertyValue);
        }
        \assert(\is_string($result));

        return $result;
    }

    /**
     * @param array<non-empty-string, string> $declarations
     *
     * @return array<non-empty-string, string>|null `null` is returned if no substitutions were made.
     */
    private function replaceVariablesInDeclarations(array $declarations): ?array
    {
        $substitutionsMade = false;
        $result = \array_map(
            function (string $propertyValue) use (&$substitutionsMade): string {
                $newPropertyValue = $this->replaceVariablesInPropertyValue($propertyValue);
                if ($newPropertyValue !== $propertyValue) {
                    $substitutionsMade = true;
                }
                return $newPropertyValue;
            },
            $declarations
        );

        return $substitutionsMade ? $result : null;
    }

    /**
     * @param array<non-empty-string, string> $declarations
     */
    private function getDeclarationsAsString(array $declarations): string
    {
        $declarationStrings = \array_map(
            static function (string $key, string $value): string {
                return $key . ': ' . $value;
            },
            \array_keys($declarations),
            \array_values($declarations)
        );

        return \implode('; ', $declarationStrings) . ';';
    }

    /**
     * @param array<non-empty-string, string> $ancestorVariableDefinitions
     *
     * @return $this
     */
    private function evaluateVariablesInElementAndDescendants(
        \DOMElement $element,
        array $ancestorVariableDefinitions
    ): self {
        $style = $element->getAttribute('style');

        // Avoid parsing declarations if none use or define a variable
        if (preg_match('/(?<![\\w\\-])--[\\w\\-]/', $style) !== 0) {
            $declarations = (new DeclarationBlockParser())->parse($style);
            $variableDefinitions =
                $this->getVariableDefinitionsFromDeclarations($declarations) + $ancestorVariableDefinitions;
            $this->currentVariableDefinitions = $variableDefinitions;

            $newDeclarations = $this->replaceVariablesInDeclarations($declarations);
            if ($newDeclarations !== null) {
                $element->setAttribute('style', $this->getDeclarationsAsString($newDeclarations));
            }
        } else {
            $variableDefinitions = $ancestorVariableDefinitions;
        }

        foreach ($element->childNodes as $child) {
            if ($child instanceof \DOMElement) {
                $this->evaluateVariablesInElementAndDescendants($child, $variableDefinitions);
            }
        }

        return $this;
    }
}

1	<?php
2
3	declare(strict_types=1);
4
5	namespace Pelago\Emogrifier\HtmlProcessor;
6
7	use Pelago\Emogrifier\Utilities\DeclarationBlockParser;
8
9	use function Safe\preg_match;
10	use function Safe\preg_replace_callback;
11
12	/**
13	* This class can evaluate CSS custom properties that are defined and used in inline style attributes.
14	*/
15	final class CssVariableEvaluator extends AbstractHtmlProcessor
16	{
17	/**
18	* temporary collection used by {@see replaceVariablesInDeclarations} and callee methods
19	*
20	* @var array<non-empty-string, string>
21	*/
22	private $currentVariableDefinitions = [];
23
24	/**
25	* Replaces all CSS custom property references in inline style attributes with their corresponding values where
26	* defined in inline style attributes (either from the element itself or the nearest ancestor).
27	*
28	* @return $this
29	*
30	* @throws \UnexpectedValueException
31	*/
32	public function evaluateVariables(): self	29✔
33	{
34	return $this->evaluateVariablesInElementAndDescendants($this->getHtmlElement(), []);	29✔
35	}
36
37	/**
38	* @param array<non-empty-string, string> $declarations
39	*
40	* @return array<non-empty-string, string>
41	*/
42	private function getVariableDefinitionsFromDeclarations(array $declarations): array	28✔
43	{
44	return \array_filter(	28✔
45	$declarations,	28✔
46	static function (string $key): bool {	28✔
47	return \substr($key, 0, 2) === '--';	28✔
48	},	28✔
49	ARRAY_FILTER_USE_KEY	28✔
50	);	28✔
51	}
52
53	/**
54	* Callback function for {@see replaceVariablesInPropertyValue} performing regular expression replacement.
55	*
56	* @param array<int, string> $matches
57	*/
58	private function getPropertyValueReplacement(array $matches): string	28✔
59	{
60	$variableName = $matches[1];	28✔
61
62	if (isset($this->currentVariableDefinitions[$variableName])) {	28✔
63	$variableValue = $this->currentVariableDefinitions[$variableName];	13✔
64	} else {
65	$fallbackValueSeparator = $matches[2] ?? '';	16✔
66	if ($fallbackValueSeparator !== '') {	16✔
67	$fallbackValue = $matches[3];	14✔
68	// The fallback value may use other CSS variables, so recurse
69	$variableValue = $this->replaceVariablesInPropertyValue($fallbackValue);	14✔
70	} else {
71	$variableValue = $matches[0];	3✔
72	}
73	}
74
75	return $variableValue;	28✔
76	}
77
78	/**
79	* Regular expression based on {@see https://stackoverflow.com/a/54143883/2511031 a StackOverflow answer}.
80	*/
81	private function replaceVariablesInPropertyValue(string $propertyValue): string	28✔
82	{
83	$pattern = '/	28✔
84	var\\(
85	\\s*+
86	# capture variable name including `--` prefix
87	(
88	--[^\\s\\),]++
89	)
90	\\s*+
91	# capture optional fallback value
92	(?:
93	# capture separator to confirm there is a fallback value
94	(,)\\s*
95	# begin capture with named group that can be used recursively
96	(?<recursable>
97	# begin named group to match sequence without parentheses, except in strings
98	(?<noparentheses>
99	# repeated zero or more times:
100	(?:
101	# sequence without parentheses or quotes
102	[^\\(\\)\'"]++
103	\|
104	# string in double quotes
105	"(?>[^"\\\\]++\|\\\\.)*"
106	\|
107	# string in single quotes
108	\'(?>[^\'\\\\]++\|\\\\.)*\'
109	)*+
110	)
111	# repeated zero or more times:
112	(?:
113	# sequence in parentheses
114	\\(
115	# using the named recursable pattern
116	(?&recursable)
117	\\)
118	# sequence without parentheses, except in strings
119	(?&noparentheses)
120	)*+
121	)
122	)?+
123	\\)
124	/x';	28✔
125
126	$callable = \Closure::fromCallable([$this, 'getPropertyValueReplacement']);	28✔
127	// The safe version is only available in "thecodingmachine/safe" for PHP >= 8.1.
128	if (\function_exists('Safe\\preg_replace_callback')) {	28✔
129	$result = preg_replace_callback($pattern, $callable, $propertyValue);	28✔
130	} else {
NEW 131	$result = \preg_replace_callback($pattern, $callable, $propertyValue);	×
132	}
133	\assert(\is_string($result));	28✔
134
135	return $result;	28✔
136	}
137
138	/**
139	* @param array<non-empty-string, string> $declarations
140	*
141	* @return array<non-empty-string, string>\|null `null` is returned if no substitutions were made.
142	*/
143	private function replaceVariablesInDeclarations(array $declarations): ?array	28✔
144	{
145	$substitutionsMade = false;	28✔
146	$result = \array_map(	28✔
147	function (string $propertyValue) use (&$substitutionsMade): string {	28✔
148	$newPropertyValue = $this->replaceVariablesInPropertyValue($propertyValue);	28✔
149	if ($newPropertyValue !== $propertyValue) {	28✔
150	$substitutionsMade = true;	26✔
151	}
152	return $newPropertyValue;	28✔
153	},	28✔
154	$declarations	28✔
155	);	28✔
156
157	return $substitutionsMade ? $result : null;	28✔
158	}
159
160	/**
161	* @param array<non-empty-string, string> $declarations
162	*/
163	private function getDeclarationsAsString(array $declarations): string	26✔
164	{
165	$declarationStrings = \array_map(	26✔
166	static function (string $key, string $value): string {	26✔
167	return $key . ': ' . $value;	26✔
168	},	26✔
169	\array_keys($declarations),	26✔
170	\array_values($declarations)	26✔
171	);	26✔
172
173	return \implode('; ', $declarationStrings) . ';';	26✔
174	}
175
176	/**
177	* @param array<non-empty-string, string> $ancestorVariableDefinitions
178	*
179	* @return $this
180	*/
181	private function evaluateVariablesInElementAndDescendants(	29✔
182	\DOMElement $element,
183	array $ancestorVariableDefinitions
184	): self {
185	$style = $element->getAttribute('style');	29✔
186
187	// Avoid parsing declarations if none use or define a variable
188	if (preg_match('/(?<![\\w\\-])--[\\w\\-]/', $style) !== 0) {	29✔
189	$declarations = (new DeclarationBlockParser())->parse($style);	28✔
190	$variableDefinitions =	28✔
191	$this->getVariableDefinitionsFromDeclarations($declarations) + $ancestorVariableDefinitions;	28✔
192	$this->currentVariableDefinitions = $variableDefinitions;	28✔
193
194	$newDeclarations = $this->replaceVariablesInDeclarations($declarations);	28✔
195	if ($newDeclarations !== null) {	28✔
196	$element->setAttribute('style', $this->getDeclarationsAsString($newDeclarations));	26✔
197	}
198	} else {
199	$variableDefinitions = $ancestorVariableDefinitions;	29✔
200	}
201
202	foreach ($element->childNodes as $child) {	29✔
203	if ($child instanceof \DOMElement) {	29✔
204	$this->evaluateVariablesInElementAndDescendants($child, $variableDefinitions);	29✔
205	}
206	}
207
208	return $this;	29✔
209	}
210	}

MyIntervals / emogrifier / 19446892823

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