xPath = $xPath; $this->useNestingLimit = $useNestingLimit; } public function collect() { $this->collectIdentifiedElements(); $this->processReferences(); $this->determineInvalidSubjects(); } /** * Resolves one subject by element. * * @param \DOMElement $element * @param bool $considerChildren Whether to search in Subject's children as well * @return Subject|null */ public function findByElement(\DOMElement $element, $considerChildren = false) { foreach ($this->subjects as $subject) { if ( $element === $subject->getElement() || $considerChildren && Helper::isElementContainedIn($element, $subject->getElement()) ) { return $subject; } } return null; } /** * Resolves subjects (plural!) by element id - in theory malformed * DOM might have same ids assigned to different elements and leaving * it to client/browser implementation which element to actually use. * * @param string $elementId * @return Subject[] */ public function findByElementId($elementId) { return array_filter( $this->subjects, function (Subject $subject) use ($elementId) { return $elementId === $subject->getElementId(); } ); } /** * Collects elements having `id` attribute (those that can be referenced). */ protected function collectIdentifiedElements() { /** @var \DOMNodeList|\DOMElement[] $elements */ $elements = $this->xPath->query('//*[@id]'); foreach ($elements as $element) { $this->subjects[$element->getAttribute('id')] = new Subject($element, $this->useNestingLimit); } } /** * Processes references from and to elements having `id` attribute concerning * their occurrence in `` statements. */ protected function processReferences() { $useNodeName = $this->xPath->createNodeName('use'); foreach ($this->subjects as $subject) { $useElements = $this->xPath->query( $useNodeName . '[@href or @xlink:href]', $subject->getElement() ); /** @var \DOMElement $useElement */ foreach ($useElements as $useElement) { $useId = Helper::extractIdReferenceFromHref( Helper::getElementHref($useElement) ); if ($useId === null || !isset($this->subjects[$useId])) { continue; } $subject->addUse($this->subjects[$useId]); $this->subjects[$useId]->addUsedIn($subject); } } } /** * Determines and tags infinite loops. */ protected function determineInvalidSubjects() { foreach ($this->subjects as $subject) { if (in_array($subject->getElement(), $this->elementsToRemove)) { continue; } $useId = Helper::extractIdReferenceFromHref( Helper::getElementHref($subject->getElement()) ); try { if ($useId === $subject->getElementId()) { $this->markSubjectAsInvalid($subject); } elseif ($subject->hasInfiniteLoop()) { $this->markSubjectAsInvalid($subject); } } catch (NestingException $e) { $this->elementsToRemove[] = $e->getElement(); $this->markSubjectAsInvalid($subject); } } } /** * Get all the elements that caused a nesting exception. * * @return array */ public function getElementsToRemove() { return $this->elementsToRemove; } /** * The Subject is invalid for some reason, therefore we should * remove it and all it's child usages. * * @param Subject $subject */ protected function markSubjectAsInvalid(Subject $subject) { $this->elementsToRemove = array_merge( $this->elementsToRemove, $subject->clearInternalAndGetAffectedElements() ); } }