How to rollback EmberJS model relations

Background

EmberJS by default has rollbackAttributes method that rollbacks model attributes, but does nothing with its belongsTo and hasMany relations. Alos it applies to changedAttribute method that returns only model’s changes attributes without relations.

Question

How to rollback model attributes with all relations?

Answer

There is an awesome EmberJS plugin that enables this ability for any model. It has a lot of options and can be configured to fit any requirement.

One more thing

But there is one more thing that does not allow to use this plugin as expected. By default Ember findRecord method returns records from the cache if it exists and in a background makes an API call. This behavior breaks the plugin because it can be that query method returns models without relations (API can be designed in this way) and findRecord method returns fully loaded model with all relations. In this case, if findRecord method was called right after query method EmberJS will return model from the cache, start API call and will not fire any ready or didUpdate model triggers after call completion so nobody knows that the model has been updated in a background. This behavior makes stored by plugin relations broken and makes the model ‘dirty’.

Solution

Override store findRecord method and make an additional plugin call:

export default DS.Store.extend({
    findRecord(name, id, options) {
        options = Object.assign({ reload: true }, options);

        return this._super(name, id, options).then((record) => {
            record.startTrack();

            return record;
        });
    }
});

As an option options = Object.assign({ reload: true }, options); can be moved to an adapter:

export default DS.RESTAdapter.extend(DataAdapterMixin, {
	shouldReloadRecord() {
		return true;
	},
});

This trick forces EmberJS to do not use cache for findRecord method, fire model ready trigger when model was loaded from the API and let plugin know that model was updated.