371 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			PHP
		
	
	
	
			
		
		
	
	
			371 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			PHP
		
	
	
	
| <?php namespace BookStack\Entities\Tools;
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| 
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| use BookStack\Entities\Models\Page;
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| use BookStack\Entities\Tools\Markdown\CustomStrikeThroughExtension;
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| use BookStack\Exceptions\ImageUploadException;
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| use BookStack\Facades\Theme;
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| use BookStack\Theming\ThemeEvents;
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| use BookStack\Util\HtmlContentFilter;
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| use BookStack\Uploads\ImageRepo;
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| use DOMDocument;
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| use DOMNodeList;
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| use DOMXPath;
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| use Illuminate\Support\Str;
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| use League\CommonMark\CommonMarkConverter;
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| use League\CommonMark\Environment;
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| use League\CommonMark\Extension\Table\TableExtension;
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| use League\CommonMark\Extension\TaskList\TaskListExtension;
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| 
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| class PageContent
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| {
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| 
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|     protected $page;
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| 
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|     /**
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|      * PageContent constructor.
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|      */
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|     public function __construct(Page $page)
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|     {
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|         $this->page = $page;
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|     }
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| 
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|     /**
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|      * Update the content of the page with new provided HTML.
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|      */
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|     public function setNewHTML(string $html)
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|     {
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|         $html = $this->extractBase64Images($this->page, $html);
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|         $this->page->html = $this->formatHtml($html);
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|         $this->page->text = $this->toPlainText();
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|         $this->page->markdown = '';
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|     }
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| 
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|     /**
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|      * Update the content of the page with new provided Markdown content.
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|      */
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|     public function setNewMarkdown(string $markdown)
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|     {
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|         $this->page->markdown = $markdown;
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|         $html = $this->markdownToHtml($markdown);
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|         $this->page->html = $this->formatHtml($html);
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|         $this->page->text = $this->toPlainText();
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|     }
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| 
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|     /**
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|      * Convert the given Markdown content to a HTML string.
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|      */
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|     protected function markdownToHtml(string $markdown): string
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|     {
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|         $environment = Environment::createCommonMarkEnvironment();
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|         $environment->addExtension(new TableExtension());
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|         $environment->addExtension(new TaskListExtension());
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|         $environment->addExtension(new CustomStrikeThroughExtension());
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|         $environment = Theme::dispatch(ThemeEvents::COMMONMARK_ENVIRONMENT_CONFIGURE, $environment) ?? $environment;
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|         $converter = new CommonMarkConverter([], $environment);
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|         return $converter->convertToHtml($markdown);
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|     }
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| 
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|     /**
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|      * Convert all base64 image data to saved images
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|      */
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|     public function extractBase64Images(Page $page, string $htmlText): string
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|     {
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|         if (empty($htmlText) || strpos($htmlText, 'data:image') === false) {
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|             return $htmlText;
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|         }
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| 
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|         $doc = $this->loadDocumentFromHtml($htmlText);
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|         $container = $doc->documentElement;
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|         $body = $container->childNodes->item(0);
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|         $childNodes = $body->childNodes;
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|         $xPath = new DOMXPath($doc);
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|         $imageRepo = app()->make(ImageRepo::class);
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|         $allowedExtensions = ['jpg', 'jpeg', 'png', 'gif', 'webp'];
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| 
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|         // Get all img elements with image data blobs
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|         $imageNodes = $xPath->query('//img[contains(@src, \'data:image\')]');
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|         foreach ($imageNodes as $imageNode) {
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|             $imageSrc = $imageNode->getAttribute('src');
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|             [$dataDefinition, $base64ImageData] = explode(',', $imageSrc, 2);
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|             $extension = strtolower(preg_split('/[\/;]/', $dataDefinition)[1] ?? 'png');
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| 
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|             // Validate extension
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|             if (!in_array($extension, $allowedExtensions)) {
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|                 $imageNode->setAttribute('src', '');
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|                 continue;
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|             }
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| 
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|             // Save image from data with a random name
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|             $imageName = 'embedded-image-' . Str::random(8) . '.' . $extension;
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|             try {
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|                 $image = $imageRepo->saveNewFromData($imageName, base64_decode($base64ImageData), 'gallery', $page->id);
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|                 $imageNode->setAttribute('src', $image->url);
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|             } catch (ImageUploadException $exception) {
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|                 $imageNode->setAttribute('src', '');
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|             }
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|         }
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| 
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|         // Generate inner html as a string
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|         $html = '';
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|         foreach ($childNodes as $childNode) {
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|             $html .= $doc->saveHTML($childNode);
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|         }
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| 
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|         return $html;
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|     }
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| 
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|     /**
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|      * Formats a page's html to be tagged correctly within the system.
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|      */
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|     protected function formatHtml(string $htmlText): string
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|     {
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|         if (empty($htmlText)) {
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|             return $htmlText;
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|         }
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| 
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|         $doc = $this->loadDocumentFromHtml($htmlText);
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|         $container = $doc->documentElement;
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|         $body = $container->childNodes->item(0);
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|         $childNodes = $body->childNodes;
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|         $xPath = new DOMXPath($doc);
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| 
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|         // Set ids on top-level nodes
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|         $idMap = [];
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|         foreach ($childNodes as $index => $childNode) {
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|             [$oldId, $newId] = $this->setUniqueId($childNode, $idMap);
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|             if ($newId && $newId !== $oldId) {
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|                 $this->updateLinks($xPath, '#' . $oldId, '#' . $newId);
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|             }
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|         }
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| 
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|         // Ensure no duplicate ids within child items
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|         $idElems = $xPath->query('//body//*//*[@id]');
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|         foreach ($idElems as $domElem) {
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|             [$oldId, $newId] = $this->setUniqueId($domElem, $idMap);
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|             if ($newId && $newId !== $oldId) {
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|                 $this->updateLinks($xPath, '#' . $oldId, '#' . $newId);
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|             }
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|         }
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| 
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|         // Generate inner html as a string
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|         $html = '';
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|         foreach ($childNodes as $childNode) {
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|             $html .= $doc->saveHTML($childNode);
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|         }
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| 
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|         return $html;
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|     }
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| 
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|     /**
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|      * Update the all links to the $old location to instead point to $new.
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|      */
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|     protected function updateLinks(DOMXPath $xpath, string $old, string $new)
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|     {
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|         $old = str_replace('"', '', $old);
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|         $matchingLinks = $xpath->query('//body//*//*[@href="' . $old . '"]');
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|         foreach ($matchingLinks as $domElem) {
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|             $domElem->setAttribute('href', $new);
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|         }
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|     }
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| 
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|     /**
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|      * Set a unique id on the given DOMElement.
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|      * A map for existing ID's should be passed in to check for current existence.
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|      * Returns a pair of strings in the format [old_id, new_id]
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|      */
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|     protected function setUniqueId(\DOMNode $element, array &$idMap): array
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|     {
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|         if (get_class($element) !== 'DOMElement') {
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|             return ['', ''];
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|         }
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| 
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|         // Stop if there's an existing valid id that has not already been used.
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|         $existingId = $element->getAttribute('id');
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|         if (strpos($existingId, 'bkmrk') === 0 && !isset($idMap[$existingId])) {
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|             $idMap[$existingId] = true;
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|             return [$existingId, $existingId];
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|         }
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| 
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|         // Create an unique id for the element
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|         // Uses the content as a basis to ensure output is the same every time
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|         // the same content is passed through.
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|         $contentId = 'bkmrk-' . mb_substr(strtolower(preg_replace('/\s+/', '-', trim($element->nodeValue))), 0, 20);
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|         $newId = urlencode($contentId);
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|         $loopIndex = 0;
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| 
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|         while (isset($idMap[$newId])) {
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|             $newId = urlencode($contentId . '-' . $loopIndex);
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|             $loopIndex++;
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|         }
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| 
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|         $element->setAttribute('id', $newId);
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|         $idMap[$newId] = true;
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|         return [$existingId, $newId];
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|     }
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| 
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|     /**
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|      * Get a plain-text visualisation of this page.
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|      */
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|     protected function toPlainText(): string
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|     {
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|         $html = $this->render(true);
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|         return html_entity_decode(strip_tags($html));
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|     }
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| 
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|     /**
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|      * Render the page for viewing
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|      */
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|     public function render(bool $blankIncludes = false): string
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|     {
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|         $content = $this->page->html;
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| 
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|         if (!config('app.allow_content_scripts')) {
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|             $content = HtmlContentFilter::removeScripts($content);
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|         }
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| 
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|         if ($blankIncludes) {
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|             $content = $this->blankPageIncludes($content);
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|         } else {
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|             $content = $this->parsePageIncludes($content);
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|         }
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| 
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|         return $content;
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|     }
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| 
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|     /**
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|      * Parse the headers on the page to get a navigation menu
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|      */
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|     public function getNavigation(string $htmlContent): array
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|     {
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|         if (empty($htmlContent)) {
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|             return [];
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|         }
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| 
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|         $doc = $this->loadDocumentFromHtml($htmlContent);
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|         $xPath = new DOMXPath($doc);
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|         $headers = $xPath->query("//h1|//h2|//h3|//h4|//h5|//h6");
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| 
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|         return $headers ? $this->headerNodesToLevelList($headers) : [];
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|     }
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| 
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|     /**
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|      * Convert a DOMNodeList into an array of readable header attributes
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|      * with levels normalised to the lower header level.
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|      */
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|     protected function headerNodesToLevelList(DOMNodeList $nodeList): array
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|     {
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|         $tree = collect($nodeList)->map(function ($header) {
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|             $text = trim(str_replace("\xc2\xa0", '', $header->nodeValue));
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|             $text = mb_substr($text, 0, 100);
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| 
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|             return [
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|                 'nodeName' => strtolower($header->nodeName),
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|                 'level' => intval(str_replace('h', '', $header->nodeName)),
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|                 'link' => '#' . $header->getAttribute('id'),
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|                 'text' => $text,
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|             ];
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|         })->filter(function ($header) {
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|             return mb_strlen($header['text']) > 0;
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|         });
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| 
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|         // Shift headers if only smaller headers have been used
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|         $levelChange = ($tree->pluck('level')->min() - 1);
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|         $tree = $tree->map(function ($header) use ($levelChange) {
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|             $header['level'] -= ($levelChange);
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|             return $header;
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|         });
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| 
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|         return $tree->toArray();
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|     }
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| 
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|     /**
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|      * Remove any page include tags within the given HTML.
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|      */
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|     protected function blankPageIncludes(string $html): string
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|     {
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|         return preg_replace("/{{@\s?([0-9].*?)}}/", '', $html);
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|     }
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| 
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|     /**
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|      * Parse any include tags "{{@<page_id>#section}}" to be part of the page.
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|      */
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|     protected function parsePageIncludes(string $html): string
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|     {
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|         $matches = [];
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|         preg_match_all("/{{@\s?([0-9].*?)}}/", $html, $matches);
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| 
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|         foreach ($matches[1] as $index => $includeId) {
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|             $fullMatch = $matches[0][$index];
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|             $splitInclude = explode('#', $includeId, 2);
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| 
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|             // Get page id from reference
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|             $pageId = intval($splitInclude[0]);
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|             if (is_nan($pageId)) {
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|                 continue;
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|             }
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| 
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|             // Find page and skip this if page not found
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|             $matchedPage = Page::visible()->find($pageId);
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|             if ($matchedPage === null) {
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|                 $html = str_replace($fullMatch, '', $html);
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|                 continue;
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|             }
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| 
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|             // If we only have page id, just insert all page html and continue.
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|             if (count($splitInclude) === 1) {
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|                 $html = str_replace($fullMatch, $matchedPage->html, $html);
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|                 continue;
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|             }
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| 
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|             // Create and load HTML into a document
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|             $innerContent = $this->fetchSectionOfPage($matchedPage, $splitInclude[1]);
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|             $html = str_replace($fullMatch, trim($innerContent), $html);
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|         }
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| 
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|         return $html;
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|     }
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| 
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| 
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|     /**
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|      * Fetch the content from a specific section of the given page.
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|      */
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|     protected function fetchSectionOfPage(Page $page, string $sectionId): string
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|     {
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|         $topLevelTags = ['table', 'ul', 'ol'];
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|         $doc = $this->loadDocumentFromHtml($page->html);
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| 
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|         // Search included content for the id given and blank out if not exists.
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|         $matchingElem = $doc->getElementById($sectionId);
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|         if ($matchingElem === null) {
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|             return '';
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|         }
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| 
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|         // Otherwise replace the content with the found content
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|         // Checks if the top-level wrapper should be included by matching on tag types
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|         $innerContent = '';
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|         $isTopLevel = in_array(strtolower($matchingElem->nodeName), $topLevelTags);
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|         if ($isTopLevel) {
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|             $innerContent .= $doc->saveHTML($matchingElem);
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|         } else {
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|             foreach ($matchingElem->childNodes as $childNode) {
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|                 $innerContent .= $doc->saveHTML($childNode);
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|             }
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|         }
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|         libxml_clear_errors();
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| 
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|         return $innerContent;
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|     }
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| 
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|     /**
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|      * Create and load a DOMDocument from the given html content.
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|      */
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|     protected function loadDocumentFromHtml(string $html): DOMDocument
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|     {
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|         libxml_use_internal_errors(true);
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|         $doc = new DOMDocument();
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|         $html = '<body>' . $html . '</body>';
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|         $doc->loadHTML(mb_convert_encoding($html, 'HTML-ENTITIES', 'UTF-8'));
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|         return $doc;
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|     }
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| }
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