Controller which handles the logic, such as saving, updating or deleting the object.

Defintion Controller: The controller interprets the mouse and keyboard inputs from the user, informing the model and/or the view to change as appropriate. Source: http://bit.ly/fQnaJI

For the time being the Controller class doesn't do much more than returning the same data as entered (JSON) object literal. Still this is by design, as there is a possibility for the 'controller' to do more than this 'stuff' (handling more than returning data) in the future.