ember-unchanged-attributes

Ember plugin which allows you to get initial value of model object's attributes after they were changed.

Sometimes, you don't need to update attributes values in view until model is saved. For example, you can have edit form in modal and you don't want values to update on background until model object is successfully saved, because it can confuse user. This plugin can help you with this issue!

Installation

ember install ember-unchanged-attributes

Usage

First, you need to import module and extend needed model.

import UnchangedAttributesMixin from 'ember-unchanged-attributes';

DS.Model.extend(UnchangedAttributesMixin, {
  name: attr(),
});

After this, you can access unchanged value of any attribute by unchanged#{AttrName} property

let user = this.store.createRecord('user', { name: 'Jack' });
user.get('unchangedName');
> "Jack"
user.set('name', 'Billy');
user.get('unchangedName');
> "Jack"

After you save object, it will reset unchanged attributes

user.save().then((user) => {
  user.get('unchangedName') // => will equal to "Billy"
});

Also, if you wan't to have unchanged properties for specific attributes only, you can specify _unchangedAttributesList in your model. And you can also specify prefix for these attributes with _unchangedPrefix.

import UnchangedAttributesMixin from 'ember-unchanged-attributes';

DS.Model.extend(UnchangedAttributesMixin, {
  _unchangedPrefix: 'original',
  _unchangedAttributesList: ['content'],

  title: attr(),
  content: attr(),
});

...

let article = this.store.createRecord('article', { title: 'Best Article', content: 'Best Content' })
article.set('content', 'Lorem Ipsum')
article.get('originalContent')
> "Best Content"
article.get('originalTitle')
> Will throw exception, since 'title' is not specified in '_unchangedAttributesList'