I wanna build a UI for a REST-API written in PHP.
First I thought it would be a good idea to build a small MVC in PHP which communicates with the API, but then I read about ext.direct and how it could expose the PHP functions to the clients.

but if I already got a REST-API, which handles login, sessions, user and business-data retrieval and all this stuff, couldn't a data store handle all this?
I mean, couldn't extjs alone handle all the stuff, so that I don't need any server side PHP anymore?