Same functionality implemented in OOP

src/MicrodataParser.php

@@ -0,0 +1,278 @@
+<?php
+
+namespace YusufKandemir\MicrodataParser;
+
+class MicrodataParser
+{
+    protected $topLevelItems;
+
+    public function __construct(\DOMDocument $dom)
+    {
+        $xpath = new \DOMXPath($dom);
+        $this->topLevelItems = $xpath->query('//*[@itemscope and not(@itemprop)]');
+    }
+
+    public function extractMicrodata()
+    {
+        // Step 1
+        $result = new \stdClass;
+
+        // Step 2
+        $items = [];
+
+        // Step 3
+        // items = map("top-level microdata items", item => getObject(item))
+        $items = array_map([$this, 'getObject'], iterator_to_array($this->topLevelItems));
+
+        /*foreach ($topLevelItems as $topLevelItem) {
+            $items[] = getObject($topLevelItem);
+        }*/
+
+        // Step 4
+        $result->items = $items;
+
+        // Step 5
+        return $result;
+    }
+
+    protected function getObject(\DOMElement $item, $memory = [])
+    {
+        // Step 1
+        $result = new \stdClass;
+
+        // Step 2 in 2nd parameter of this function
+        // $memory = [];
+
+        // Step 3
+        $memory[] = $item;
+
+        // Step 4
+        $itemtype = $item->getAttribute('itemtype');
+        $result->type = $itemtype ? preg_split('/\s+/', $itemtype) : [];
+        // @todo Check if types are valid absolute urls
+
+        // Step 5
+        if ($itemId = $item->getAttribute('itemid')) {
+            $result->id = $itemId;
+        }
+        // @todo Check if item ids are valid absolute urls or like isbn:xxx
+
+        // Step 6
+        $properties = new \stdClass;
+
+        // Step 7
+        foreach ($this->getProperties($item) as $element) {
+            $value = $this->getPropertyValue($element);
+
+            if ($this->isItem($value)) {
+                foreach ($memory as $memory_item) {
+                    if ($element->isSameNode($memory_item)) {
+                        $value = 'ERROR';
+                    }
+                }
+
+                if ($value != 'ERROR') {
+                    $value = $this->getObject($value, $memory);
+                }
+            }
+
+            foreach ($this->getPropertyNames($element) as $name) {
+                $properties->{$name}[] = $value;
+            }
+        }
+
+        // Step 8
+        $result->properties = $properties;
+
+        // Step 9
+        return $result;
+    }
+
+    protected function getPropertyNames(\DOMElement $item)
+    {
+        // Step 1
+        $itemprop = $item->getAttribute('itemprop');
+        $tokens = $itemprop ? preg_split('/\s+/', $itemprop) : [];
+
+        // Step 2
+        $properties = [];
+
+        // Step 3
+        foreach ($tokens as $token) {
+            if ($this->isAbsoluteUri($token)) {
+                $properties[] = $token;
+            } elseif ($this->isTypedItem($item)) {
+                $properties[] = /*$vocabularyIdentifier . */ $token;
+            } else {
+                $properties[] = $token;
+            }
+        }
+
+        $properties = array_unique($properties);
+
+        return $properties;
+    }
+
+    protected function getProperties(\DOMElement $root)
+    {
+        // Step 1
+        $results = [];
+        $memory = [];
+        $pending = [];
+
+        // Step 2
+        $memory[] = $root;
+
+        // Step 3
+        if ($root->hasChildNodes()) {
+            $childNodes = iterator_to_array($root->childNodes);
+
+            $childNodes = array_filter($childNodes, function ($node) {
+                return $node instanceof \DOMElement;
+            }); // Get only DOMElements
+
+            $pending = array_merge($pending, $childNodes);
+        }
+
+        // Step 4
+        if ($root->hasAttribute('itemref')) {
+            $tokens = preg_split('/\s+/', $root->getAttribute('itemref'));
+
+            foreach ($tokens as $token) {
+                // @todo Implement xpath query and get the first item
+            }
+        }
+
+        // Step 5
+        while ($pending) {
+            // Step 6
+            $current = array_pop($pending);
+
+            // Step 7
+            // in_array can't compare objects
+            /*if (in_array($current, $memory)) {
+                // There is MicrodataError
+                continue;
+            }*/
+            $error = false;
+
+            foreach ($memory as $memory_item) {
+                if ($current->isSameNode($memory_item)) {
+                    // There is MicrodataError
+                    $error = true;
+                    break;
+                }
+            }
+
+            if ($error) {
+                continue;
+            }
+
+            // Step 8
+            $memory[] = $current;
+
+            // Step 9
+            if (! $current->hasAttribute('itemscope')) {
+                if ($current->hasChildNodes()) {
+                    $childNodes = iterator_to_array($current->childNodes);
+
+                    $childNodes = array_filter($childNodes, function ($node) {
+                        return $node instanceof \DOMElement;
+                    });
+
+                    $pending = array_merge($pending, $childNodes);
+                }
+            }
+
+            // Step 10
+            if ($current->hasAttribute('itemprop') && /* hasPropertyNames */ $this->getPropertyNames($current)) {
+                $results[] = $current;
+            }
+
+            // Step 11: Return to loop
+        }
+
+        // Step 12: End of loop. Sort results in tree order.
+
+        $results = array_reverse($results);
+
+        // Step 13
+        return $results;
+    }
+
+    protected function getPropertyValue(\DOMElement $item)
+    {
+
+        if ($item->hasAttribute('itemscope')) {
+            return $item;
+        }
+
+        if ($item->hasAttribute('content')) {
+            return $item->getAttribute('content');
+        }
+
+        $base = $item->ownerDocument->documentURI;
+
+        switch ($item->tagName) {
+            case 'audio':
+            case 'embed':
+            case 'iframe':
+            case 'img':
+            case 'source':
+            case 'track':
+            case 'video':
+                if ($item->hasAttribute('src')) {
+                    $result = $item->getAttribute('src');
+
+                    // @todo check against protocol relative urls like "//example.com/test.jpg"
+                    return $this->isAbsoluteUri($result) ? $result : $base.$result;
+                }
+            case 'a':
+            case 'area':
+            case 'link':
+                if ($item->hasAttribute('href')) {
+                    $result = $item->getAttribute('href');
+
+                    return $this->isAbsoluteUri($result) ? $result : $base.$result;
+                }
+            case 'object':
+                if ($item->hasAttribute('data')) {
+                    $result = $item->getAttribute('data');
+
+                    return $this->isAbsoluteUri($result) ? $result : $base.$result;
+                }
+            case 'data':
+            case 'meter':
+                if ($item->hasAttribute('value')) {
+                    return $item->getAttribute('value');
+                }
+            case 'time':
+                if ($item->hasAttribute('datetime')) {
+                    return $item->getAttribute('datetime');
+                }
+            default:
+                return $item->textContent;
+        }
+    }
+
+    protected function isItem($element)
+    {
+        return $element instanceof \DOMElement && $element->hasAttribute('itemscope');
+    }
+
+    protected function isTypedItem(\DOMElement $item)
+    {
+        $tokens = [];
+
+        if ($item->hasAttribute('itemtype')) {
+            $tokens = preg_split("/\s+/", $item->getAttribute('itemtype'));
+        }
+
+        return !empty($tokens);
+    }
+
+    protected function isAbsoluteUri(string $uri)
+    {
+        return preg_match("/^\w+:/", trim($uri));
+    }
+}