Add ability to check that element matches selector

Author: Imangazaliev

src/DiDom/Element.php

@@ -144,6 +144,72 @@ public function count($expression, $type = Query::TYPE_CSS)
         return $this->toDocument()->count($expression, $type);
     }
 
+    /**
+     * Checks that the node matches selector.
+     * 
+     * @param string $selector CSS selector
+     * @param bool $strict
+     *
+     * @return bool
+     */
+    public function matches($selector, $strict = false)
+    {
+        if (!$strict) {
+            // remove child nodes
+            $node = $this->node->cloneNode();
+
+            $innerHtml = $node->ownerDocument->saveXml($node, LIBXML_NOEMPTYTAG);
+            $html = "<root>$innerHtml</root>";
+
+            $selector = 'root > '.trim($selector);
+
+            $document = new Document($html);
+
+            return $document->has($selector);
+        }
+
+        $segments = Query::getSegments($selector);
+
+        $segments['tag'] = array_key_exists('tag', $segments) ? $segments['tag'] : null;
+
+        if ($segments['tag'] !== $this->tag and $segments['tag'] !== '*') {
+            return false;
+        }
+
+        $segments['id'] = array_key_exists('id', $segments) ? $segments['id'] : null;
+
+        if ($segments['id'] !== $this->getAttribute('id')) {
+            return false;
+        }
+
+        $classes = $this->hasAttribute('class') ? explode(' ', trim($this->getAttribute('class'))) : [];
+
+        $segments['classes'] = array_key_exists('classes', $segments) ? $segments['classes'] : [];
+
+        $diff1 = array_diff($segments['classes'], $classes);
+        $diff2 = array_diff($classes, $segments['classes']);
+
+        if (count($diff1) > 0 or count($diff2) > 0) {
+            return false;
+        }
+
+        $attributes = $this->attributes();
+
+        unset($attributes['id']);
+        unset($attributes['class']);
+
+        $segments['attributes'] = array_key_exists('attributes', $segments) ? $segments['attributes'] : [];
+
+        $diff1 = array_diff_assoc($segments['attributes'], $attributes);
+        $diff2 = array_diff_assoc($attributes, $segments['attributes']);
+
+        if (count($diff1) > 0 or count($diff2) > 0) {
+            return false;
+        }
+
+        return true;
+    }
+
     /**
      * Determine if an attribute exists on the element.
      *

tests/DiDom/ElementTest.php

@@ -195,6 +195,29 @@ public function testCount()
         $this->assertEquals(0, $document->count('li'));
     }
 
+    public function testMatches()
+    {
+        $element = new Element('ul', null, ['id' => 'foo', 'class' => 'bar baz']);
+
+        $this->assertTrue($element->matches('ul'));
+        $this->assertTrue($element->matches('#foo'));
+        $this->assertTrue($element->matches('.bar'));
+        $this->assertTrue($element->matches('ul#foo.bar.baz'));
+        $this->assertFalse($element->matches('a#foo.bar.baz'));
+
+        // strict
+        $this->assertTrue($element->matches('ul#foo.bar.baz', true));
+        $this->assertFalse($element->matches('ul#foo.bar', true));
+        $this->assertFalse($element->matches('ul#foo', true));
+        $this->assertFalse($element->matches('ul.bar.baz', true));
+        $this->assertFalse($element->matches('#foo.bar.baz', true));
+        $this->assertFalse($element->matches('ul.bar.baz', true));
+
+        $element = new Element('p');
+
+        $this->assertTrue($element->matches('p', true));
+    }
+
     public function testHasAttribute()
     {
         $node = $this->createNode('input');