Ember: Automatically destroy uncommited new model instance when navigating away from route

Question

I have a /posts/new route for creating a new post record. I am using the ember-form-for add-on, which provides helpers for creating forms. You are supposed to pass the form-for component an object, and when you submit the form, form-for calls the save() method on the object. So it looks like you're supposed to pass it an instance of a model directly.

This means that I need to create a new post model instance automatically when I navigate to this route. This is all good so long as I submit the form and create the new model instance. But what if I go to this route and then leave without submitting (i.e. saving) the new instance? It seems this will leave an unsaved model instance lying around in the store. Do I need to manually destroy this instance if I navigate away from the route, or is there some more elegant way to do this? If I do need to manually destroy it, what's the appropriate hook? deactivate is a route method but my new instance is stored on the controller.

NOTE: I've seen this existing answer, but it's from 2013. Wondering if there's something cleaner available now.

deactivate is good. Or just keep it and reuse it when the user returns. You can access the controller from the route. — Lux

Abhilash L R Abhilash L R · Accepted Answer · 2018-06-01T05:27:35

Since you are creating a new model, you need to manually destroy it (roll it back). This can be done in the route's resetController hook. Something like below:

// Your route.js file
import Route from '@ember/routing/route';
import { get } from '@ember/object';

export default Ember.Route.extend({
  model() {
    return get(this, 'store').createRecord('some-model');
  },
  resetController(controller, isExiting) {
    if (isExiting) {
      get(controller, 'model').rollbackAttributes();
    }
  }
});

Refer: https://emberjs.com/api/ember-data/3.1/classes/DS.Model/methods/rollbackAttributes?anchor=rollbackAttributes

Ember: Automatically destroy uncommited new model instance when navigating away from route

1 Answers