schemaorg.php

<?php
 
namespace Bitrix\Main\UrlPreview\Parser;
 
use Bitrix\Main\Context;
use Bitrix\Main\Text\Encoding;
use Bitrix\Main\UrlPreview\HtmlDocument;
use Bitrix\Main\UrlPreview\Parser;
 
class SchemaOrg extends Parser
{
    protected $dom;
 
    protected $schemaMetadata = array();
 
    protected $documentEncoding;
 
    public function handle(HtmlDocument $document)
    {
        $this->documentEncoding = $document->getEncoding();
        if(strpos($document->getHtml(), 'itemscope') === false)
            return null;
 
        if(!$this->initializeDom($document))
            return null;
 
        if(!$this->getSchemaMetadata())
            return null;
 
        if($document->getTitle() == '' && isset($this->schemaMetadata['name']))
        {
            $document->setTitle($this->schemaMetadata['name']);
        }
 
        if($document->getDescription() == '' && isset($this->schemaMetadata['description']))
        {
            $document->setDescription($this->schemaMetadata['description']);
        }
 
        if($document->getImage() == '' && isset($this->schemaMetadata['image']))
        {
            $document->setImage($this->schemaMetadata['image']);
        }
    }
 
    protected function getSchemaMetadata()
    {
        // Starting with first node with itemscope attribute, to prevent walking over full document.
        $xpath = new \DOMXPath($this->dom);
        $itemScopeNodes = $xpath->query('//*[@itemscope]');
 
        if(!is_a($itemScopeNodes, '\DOMNodeList') || $itemScopeNodes->length < 1)
            return false;
 
        $mainNode = $itemScopeNodes->item(0);
        if(!is_a($mainNode, '\DOMElement'))
            return false;
 
        $this->walkDomTree($mainNode);
 
        return true;
    }
 
    protected function walkDomTree(\DOMElement $currentNode, $currentDepth = 0)
    {
        $this->handleNode($currentNode);
        foreach($currentNode->childNodes as $childNode)
        {
            if(is_a($childNode, '\DOMElement') && !($currentDepth == 0 xor $currentNode->hasAttribute('itemscope')))
            {
                $this->walkDomTree($childNode, $currentDepth + 1);
            }
        }
    }
 
    protected function getSchemaPropertyValue(\DOMElement $node)
    {
        $result = null;
 
        switch($node->tagName)
        {
            case 'img':
                $result =  $node->getAttribute('src');
                break;
            case 'meta':
                $result = $node->getAttribute('content');
                break;
            case 'a':
                $result = $node->getAttribute('href');
                break;
            case 'time':
                if($node->hasAttribute('datetime'))
                    $result = $node->getAttribute('datetime');
                else
                    $result = $node->textContent;
                break;
            case 'div':
                $result = $this->getNodeInnerHtml($node);
                break;
            case 'p':
            case 'span':
            case 'h1':
            case 'h2':
            case 'h3':
            case 'h4':
            case 'h5':
            case 'h6':
                $result = $node->textContent;
                break;
        }
 
        // dom extension's internal encoding is always utf-8
        $result = Encoding::convertEncoding($result, 'utf-8', $this->documentEncoding);
        $result = trim($result);
        return ($result <> '' ? $result : null);
    }
 
    protected function handleNode(\DOMElement $node)
    {
        if($node->hasAttribute('itemprop') && !$node->hasAttribute('itemscope'))
        {
            $propertyName = mb_strtolower($node->getAttribute('itemprop'));
            $propertyValue = $this->getSchemaPropertyValue($node);
            $this->schemaMetadata[$propertyName] = $propertyValue;
        }
    }
 
    protected function getNodeInnerHtml(\DOMElement $element)
    {
        $innerHTML = "";
        $children  = $element->childNodes;
 
        foreach ($children as $child)
        {
            $innerHTML .= $element->ownerDocument->saveHTML($child);
        }
 
        return $innerHTML;
    }
 
    protected function initializeDom(HtmlDocument $document)
    {
        if(!class_exists('DOMDocument'))
        {
            return false;
        }
 
        $this->dom = new \DOMDocument();
        // Prevents parsing errors bubbling
        libxml_use_internal_errors(true);
        $result = $this->dom->loadHTML('<?xml encoding="'.$document->getEncoding().'">'.$document->getHtml(), LIBXML_COMPACT);
 
        return $result;
    }
}