ember-ohm

Attribute serialization, transformation and change tracking for regular, plain old Ember.Object's.

Installation

$ ember install ember-ohm

Usage

Model

To get everything, extend the Model:

import Ohm from 'ember-ohm/model';

User = Ohm.extend({
  name: Ohm.attr('string'),
  age: Ohm.attr('number'),
  xp: Ohm.attr('number', {readOnly: true});
});

user = User.create({name: 'Braden', age: '28', xp: 9000});

Serialization/Transformation

Serializing your model's attributes goes like so:

user.serialize(); // => {name: 'Braden', age: 28}
user.serialize('xp', 'age'); // => {xp: 9000, age: 28}

Important: Calling serialize with no arguments observes the attribute's readOnly option. Passing a variable number of properties to serialize ignores that option.

The default attribute transforms are default, boolean, number, string and array. You can see all those here.

Custom Transform

Registering a custom transform is easy, too. Say we want to create a transform that uses the moment.js library:

1. In your application directory, create a transforms/moment.js file.

2. Write this code:

   /* global moment */
   
   export default {
     serialize(context, options, value) {
       return moment(value).toISOString();
     },
   
     deserialize(context, options, value) {
       return moment(value, options.parseFormat);
     }
   };

3. Meanwhile, on Mele Island (TM)...

   User = Ohm.Model.extend({
     createdAt: Ohm.attr('momentjs', {parseFormat: 'MM-DD-YY'})
   });
   
   user = User.create({createdAt: '7-7-85'});
   user.get('createdAt'); // => moment.js object
   user.serialize(); // => {createdAt: '1995-08-09T05:00:00.000Z'}

Note: The context variable is used just the object/record whose attribute is being transformed.

Change Tracking

Ohm.attr can tracks changes on an any Ember.Object, but using it with ember-ohm/model is more useful. Take the following:

import Ohm from 'ember-ohm/model';

User = Ohm.extend({
  name: Ohm.attr('string'),
  age: Ohm.attr('number')
});

user = User.create({name: 'Braden', age: 28});

isDirty, isClean and {attr}Changed

Using the above object definition, we can have to following:

user.get('isDirty'); // => false
user.get('isClean'); // => true
user.get('nameChanged'); // => false

user.set('name', 'Brodie');

user.get('isDirty'); // => true
user.get('isClean'); // => false
user.get('nameChanged'); // => true

Comiting and reverting

We can also commit and rollback changes manually. The power is yours!!!

// Commit
user.get('isDirty'); // => false
user.set('name', 'New Name');
user.get('nameChanged'); // => true
user.get('isDirty'); // => true

user.commit();
user.get('name'); // => 'New Name'
user.get('nameChanged'); // => false
user.get('isDirty'); // => false

// Revert
user.set('name' 'Jimmy');
user.get('nameChanged'); // => true
user.get('isDirty'); // => true

user.revert();
user.get('name', 'New Name');
user.get('nameChanged'); // => false
user.get('isDirty'); // => false

You can also commit and revert changes to individual attributes:

// Commit
user.set('name', 'New Name');
user.set('age', 23);

user.commit('name')
user.get('nameChanged'); // => false
user.get('ageChanged'); // => true
user.get('isDirty'); // => true

// Revert
user.set('name', 'Jimmy');
user.set('age', 42);

user.revert('name');
user.get('name') // => 'New Name'
user.get('nameChanged'); // => false

user.get('age') // => 42
user.get('ageChanged'); // => true
user.get('isDirty'); // => true

Running Tests

• npm test (Runs ember try:testall to test your addon against multiple Ember versions)
• ember test
• ember test --server

Building

• ember build

For more information on using ember-cli, visit http://www.ember-cli.com/.