Emberjs : how to display loading spinner and notification messages on model operations

I am using ember.js 1.2 and facing a problem while trying to display loading spinner and notification messages during the crud operations on my models.

Here is the code :

var MyModelController = Ember.ObjectController.extend({
  needs: ['application'],
  application: Ember.computed.alias("controllers.application"),
  actions: {
    save: function() {
      var _this = this;

      // Display the spinner
      this.get('application').get('loading').trigger(true);

      this.get('model').save().then(function(response) {
        // Hide the spinner
        _this.get('application').get('loading').trigger(false);

        // Display the success message
        _this.get('application').get('flash').success('The model has been updated.');
      }, function(response) {
        // Hide the loading spinner
        _this.get('application').get('loading').trigger(false);

        // Display the error message
        _this.get('application').get('flash').danger('Error updating the model.');
      });
    }
  }
});

Two main problems here :

• First : the spinner is displayed with a translation that takes 0.5s but the save operation is performed with less duration and the spinner is displayed and disappears immediately. Here I would like to set a 1s timer before the save operation is called on my model to ensure the animation is performed correctly. How could it be possible ?

• Second : the success method on my flash object is binded to the specific {{view.message}} on the template. If I call this method outside the 'then' of the promise, the message is well displayed, but in my case it is not as if the binding is not done. Did I miss something in the way to use the promise ? How could it be possible to display this message ?