Added replaceNode method

implements paquettg#52

Author: paquettg

src/PHPHtmlParser/Dom/InnerNode.php

@@ -181,6 +181,7 @@ public function removeChild($id)
      * @param int $id
      * @return AbstractNode
      * @uses $this->getChild()
+     * @throws ChildNotFoundException
      */
     public function nextChild($id)
     {
@@ -196,6 +197,7 @@ public function nextChild($id)
      * @param int $id
      * @return AbstractNode
      * @uses $this->getChild()
+     * @throws ChildNotFoundException
      */
     public function previousChild($id)
     {
@@ -223,6 +225,25 @@ public function isChild($id)
         return false;
     }
 
+    /**
+     * Removes the child with id $childId and replace it with the new child
+     * $newChild.
+     *
+     * @param int $childId
+     * @param AbstractNode $newChild
+     * @throws ChildNotFoundException
+     */
+    public function replaceChild($childId, AbstractNode $newChild)
+    {
+        $oldChild = $this->getChild($childId);
+        $keys = array_keys($this->children);
+        $index = array_search($childId, $keys, true);
+        $keys[$index] = $newChild->id();
+        $this->children = array_combine($keys, $this->children);
+        $this->children[$newChild->id()] = $newChild;
+        unset($oldChild);
+    }
+
     /**
      * Checks if the given node id is a descendant of the
      * current node.

tests/Node/ParentTest.php

@@ -137,6 +137,19 @@ public function testLastChild()
 		$this->assertEquals($child3->id(), $parent->lastChild()->id());
 	}
 
+	public function testReplaceChild()
+	{
+		$parent = new Node;
+		$child  = new Node;
+		$child2 = new Node;
+		$child3 = new Node;
+		$parent->addChild($child);
+		$parent->addChild($child2);
+		$parent->replaceChild($child->id(), $child3);
+
+		$this->assertFalse($parent->isChild($child->id()));
+	}
+
 	/**
 	 * @expectedException PHPHtmlParser\Exceptions\CircularException
 	 */