Question

I copied this login example for my own needs. It runs fine. But I am asking myself: why do I need the Ember.run.later(this, this._serverLogin, 100); line? Like the comment said it is only for simulating the delay. Ok. But if I change it to this:

// Create the login controller
  MyApp.loginController = Ember.Object.create({
    username: '',
    password: '',
    isError: false,

    tryLogin: function() {
      if(this.get('username') === MyApp.USERNAME &&
         this.get('password') === MyApp.PASSWORD) {
        this.set('isError', false);
        this.set('username', '');
        this.set('password', '');
        MyApp.stateManager.send('loginSuccess');
      } else {
        this.set('isError', true);
        MyApp.stateManager.send('loginFail');
      }
    },
  });   

without Ember.run.later(this, this._serverLogin, 100);, I get Uncaught Error: <Ember.StateManager:ember270> could not respond to event loginSuccess in state loggedOut.awaitingCredentials. So I thought probably I need this delay to get the stateManager changed before or somethign like that. But when I run the old code with Ember.run.later(this, this._serverLogin, 0); it still works. So, whats different? The documentation of ember didnt gave any hints.

Answer 1

It’s because your StateManager is still in the early state setup process when calling a sendEvent (loginSuccess/loginFailed).

By delaying the event sending w/ Ember.run.later, your code is processed in a next run loop, and the state is properly setup.

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That being said, you are using Ember in a very old fashion. You should have a look at the state-of-the-art way to manage app routes.