I do it two ways depending on the application target.
My preferred method is using a LocalStorage proxy for my models I want to save locally, that way there is no change in how I interact with them in the application and it's a bit more handy when relaunching your application to set things up with out DB calls.
Alternatively, I create a global variable when starting the application. Inside the launch function do something like this.
var app = Ext.application({
name: 'MyApp',
launch: function() {
MyApp.model.User.load('profile', {
scope: this,
success: function(user) {
// Setup the app space under your Application namespace
// so you don't conflict with anything the the ExtJS framework has set
MyApp.app.user = user;
}
}
}
}
That way throughout your application, you'll have access to the current User's model through the variable MyApp.user
So this can then be used in all areas of your application
var currentUserName = MyApp.app.user.get('name');
The downside of this is that you are introducing a global variable which is considered bad practise when it can be avoided.
I don't see there being anything wrong with constructing a base controller like you have suggested, but if you are doing it purely for access to the session variables you want to store I would suggest it's maybe a bit overkill.