AngularJS: Call a particular function before any partial page controllers

Question

I want to call a particular function: GetSession() at the beginning of my application load. This function makes a $http call and get a session token: <

Answer 1

You can't postpone the initialisation of controllers.

You may put your controller code inside a Session promise callback:

myApp.factory( 'session', function GetSession($http, $q){
    var defer = $q.defer();

    $http({
        url: GetSessionTokenWebMethod,
        method: "POST",
        data: "{}",
        headers: { 'Content-Type': 'application/json' }
    }).success(function (data, status, headers, config) {
        GlobalSessionToken = data;
        defer.resolve('done');
    }).error(function (data, status, headers, config) {
        console.log(data);
        defer.reject();
    });

    return defer.promise;
} );

myApp.controller( 'ctrl', function($scope,session) {
   session.then( function() {
      //$scope.whatever ...
   } ); 
} );

Alternative: If you don't want to use such callbacks, you could have your session request synchronous, but that would be a terrible thing to do.