[Form] Added all() method to the FormBuilder class

In order to perform some introspection on a FormBuilder instance,
we need to be able to get its children. Almost everything is accessible
in this class, but the children are not.

This PR adds a all() method to respect the current API (get(), remove(),
...).

src/Symfony/Component/Form/FormBuilder.php

@@ -643,6 +643,16 @@ class FormBuilder
         return isset($this->children[$name]);
     }
 
+    /**
+     * Returns the children.
+     *
+     * @return array
+     */
+    public function all()
+    {
+        return $this->children;
+    }
+
     /**
      * Creates the form.
      *

src/Symfony/Component/Form/Tests/FormBuilderTest.php

@@ -110,6 +110,22 @@ class FormBuilderTest extends \PHPUnit_Framework_TestCase
         $this->assertTrue($this->builder->has('foo'));
     }
 
+    public function testAll()
+    {
+        $this->assertEquals(0, count($this->builder->all()));
+        $this->assertFalse($this->builder->has('foo'));
+
+        $this->builder->add('foo', 'text');
+        $children = $this->builder->all();
+
+        $this->assertTrue($this->builder->has('foo'));
+        $this->assertEquals(1, count($children));
+        $this->assertArrayHasKey('foo', $children);
+
+        $foo = $children['foo'];
+        $this->assertEquals('text', $foo['type']);
+    }
+
     public function testAddFormType()
     {
         $this->assertFalse($this->builder->has('foo'));