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<?php |
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namespace enshrined\svgSanitize; |
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|
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class Helper |
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{ |
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const XLINK_NAMESPACE_URI = 'http://www.w3.org/1999/xlink'; |
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|
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/** |
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* Resolves the `href`/`xlink:href` value of an element. |
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* |
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* The lookup is case insensitive on purpose: `Sanitizer::cleanHrefAttributes()` |
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* normalizes names such as `HrEf`/`xlink:HrEf` back to `href`/`xlink:href`, |
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* so anything consuming this helper has to see those attributes as well - |
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* otherwise a mixed-case name hides the reference from e.g. the `<use>` |
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* reference graph, which is built before that normalization happens. |
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* |
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* @param \DOMElement $element |
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* @return string|null |
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*/ |
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public static function getElementHref(\DOMElement $element) |
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{ |
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if ($element->hasAttribute('href')) { |
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return $element->getAttribute('href'); |
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} |
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if ($element->hasAttributeNS(self::XLINK_NAMESPACE_URI, 'href')) { |
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return $element->getAttributeNS(self::XLINK_NAMESPACE_URI, 'href'); |
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} |
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foreach ($element->attributes as $attribute) { |
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if (!$attribute instanceof \DOMAttr |
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|| strtolower($attribute->localName) !== 'href' |
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) { |
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continue; |
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} |
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$prefix = strtolower((string)$attribute->prefix); |
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if ($prefix === '' || $prefix === 'xlink') { |
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return $attribute->value; |
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} |
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} |
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return null; |
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} |
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|
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/** |
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* @param string $href |
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* @return string|null |
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*/ |
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public static function extractIdReferenceFromHref($href) |
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{ |
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if (!is_string($href) || strpos($href, '#') !== 0) { |
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return null; |
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} |
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return substr($href, 1); |
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} |
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|
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/** |
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* @param \DOMElement $needle |
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* @param \DOMElement $haystack |
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* @return bool |
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*/ |
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public static function isElementContainedIn(\DOMElement $needle, \DOMElement $haystack) |
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{ |
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if ($needle === $haystack) { |
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return true; |
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} |
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foreach ($haystack->childNodes as $childNode) { |
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if (!$childNode instanceof \DOMElement) { |
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continue; |
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} |
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if (self::isElementContainedIn($needle, $childNode)) { |
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return true; |
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} |
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} |
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return false; |
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} |
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} |
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|
