[Config] Introduce BuilderAwareInterface

src/Symfony/Component/Config/Definition/Builder/BuilderAwareInterface.php

@@ -0,0 +1,22 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Config\Definition\Builder;
+
+/**
+ * An interface that can be implemented by nodes which build other nodes.
+ *
+ * @author Roland Franssen <franssen.roland@gmail.com>
+ */
+interface BuilderAwareInterface
+{
+    public function setBuilder(NodeBuilder $builder);
+}

src/Symfony/Component/Config/Definition/Builder/NodeBuilder.php

@@ -186,7 +186,7 @@ class NodeBuilder implements NodeParentInterface
      */
     public function append(NodeDefinition $node)
     {
-        if ($node instanceof ParentNodeDefinitionInterface) {
+        if ($node instanceof BuilderAwareInterface) {
             $builder = clone $this;
             $builder->setParent(null);
             $node->setBuilder($builder);

src/Symfony/Component/Config/Definition/Builder/ParentNodeDefinitionInterface.php

@@ -16,11 +16,9 @@ namespace Symfony\Component\Config\Definition\Builder;
  *
  * @author Victor Berchet <victor@suumit.com>
  */
-interface ParentNodeDefinitionInterface
+interface ParentNodeDefinitionInterface extends BuilderAwareInterface
 {
     public function children();
 
     public function append(NodeDefinition $node);
-
-    public function setBuilder(NodeBuilder $builder);
 }