feature #223 Allow easier override of the "new" action. (Pierstoval)

This PR was merged into the master branch.

Discussion
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Allow easier override of the "new" action.

With this commit, we can easily customize the instanciation of our entities.

I'm proposing this modification because we have a specific case in which we only want to add default contents in a brand new instanciated object, but the content is retrieved via webservice, so I'm doing it in the controller.

Also, this simple workaround allows the users to override the method and create new `User` entity in the FOSUserBundle by returning a new User object using the
`$this->container->get('fos_user.user_manager')->createUser()` instruction.

I think this is useful 😃

Commits
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a937046 Added an "instanciateNewEntity" controller method

Controller/AdminController.php

@@ -219,8 +219,7 @@ protected function showAction()
  */
  protected function newAction()
  {
- $entityFullyQualifiedClassName = $this->entity['class'];
- $item = new $entityFullyQualifiedClassName();
+ $item = $this->instanciateNewEntity();
 
  $fields = $fields = $this->entity['new']['fields'];
  $newForm = $this->createNewForm($item, $fields);
@@ -321,6 +320,18 @@ protected function ajaxEdit()
 
  return new Response((string) $newValue);
  }
+
+ /**
+ * Creates a new object of the current managed entity.
+ * This method is mostly here for override convenience, because it allows
+ * the user to use his own method to customize the entity instanciation.
+ * 
+ * @return object
+ */
+ protected function instanciateNewEntity() {
+ $entityFullyQualifiedClassName = $this->entity['class'];
+ return new $entityFullyQualifiedClassName();
+ }
 
  /**
  * Allows applications to modify the entity associated with the item being