ModelSaveRelationsMixin.js

ModelSaveRelationsMixin.js

/**
* Creates a mixin that saves hasMany relations (this comes in handy when filtering tree data)
*
* @class ModelSaveRelationsMixin
* @main ModelSaveRelationsMixin
* @constructor
*/

/*

	Might be worth adding this code to your model for detection of changes

	App.SomeModel = DS.Model.extend({
	  // Model is dirty if any child relations have changed
	  isDirty: function() {
	    return this._super('isDirty') ||
	      this._savedRelations && Ember.keys(this._savedRelations).any(function(key) {
	        // Deep compare requires Underscore.js
	        return !_.isEqual(this._savedRelations[key], this.get(key).toArray()) ||
	          this.get(key).anyBy('isDirty');
	      }, this);
	  }.property('currentState', ).readOnly() // list all relationships keys here with both `.[]` and `[email protected]`
	});

 */

var ModelSaveRelationsMixin = Ember.Mixin.create({

	/*
	 * When the record is fetched, save its relations so they can be reverted
	 * @method _saveRelations
	 */
	_saveRelations: function() {
		var savedRelations = this._savedRelations = {};
		this.constructor.eachRelationship(function(key, relationship) {
			if (relationship.kind === 'hasMany') {
				savedRelations[key] = this.get(key).toArray();
			}
		}, this);
	}.on('didLoad', 'didCreate', 'didUpdate'),

	/*
	 * Rollback relations as well as attributes
	 * @method rollback
	 */
	rollback: function() {
		// Revert attributes like normal
		this._super();

		// Revert relationships to their state at last fetch
		if (this._savedRelations) {
			Ember.keys(this._savedRelations).forEach(function(key) {
				this.suspendRelationshipObservers(function() {
					this.get(key).setObjects(this._savedRelations[key]);
				}, this);

				// Rollback child records that have changed as well (optional)
				// this.get(key).filterBy('isDirty').invoke('rollback');
			}, this);
		}
	}
});