Since Ember Data v1.0.0-beta.8, a lot has changed. Since we didn't write a blog
post for beta.8, this blog post will contain features in both beta.8 and beta.9.
New Release Schedule
Since the first beta release for Ember Data 1.0, Ember Data has typically been
released when we felt like critical features or bugfixes were merged. Due to the
ever changing nature of Ember Data, we'd like to reward Ember Data users for
keeping up with changes by providing more frequent releases until a release
candidate emerges. Beginning Monday, August 18th 2014, Ember Data will release a
new beta version every 3 weeks. The builds will be available on the builds
page, Bower, Rubygems, and soon, NPM.
Breaking Changes
Object.create shim required
Ember Data now requires an Object.create polyfill for environments without
Object.create or incorrect Object.create implementations such as Internet
Explorer 8. Ember.js will be shipping with an Object.create polyfill in 1.8.0.
If you are using stable builds of Ember, we recommend using
ES5Shim's es5-sham.js file available on NPM and Bower.
You can refer to Kangax's Compatibility Tables to
see if you need the shim.
Ember Data uses Object.create under the hood for faster and collision-free
caches.
Dates Serialized with ISO8601 by Default
Due to the various ways dates can be serialized across the wire,
Ember Data has decided to use the well-known, well-supported, and accurate
ISO8601 format. Although the JavaScript programming language has had
support for ISO8601 strings since ECMAScript5, environment such as
Internet Explorer 8 do not support Date.prototype.toISOstring. However, Ember
Data does include a shim so you need no further work here except to make sure
your backend is supporting ISO8601.
RESTAdapter.prototype.findMany changed behavior and method signature
You should see the findMany documentation if you have overridden
the findMany method in your adapter.
HasMany Coalescing Now Opt-In
See the section below on "Coalescing Find Requests" for more information.
Previously, if you did not sideload data for a hasMany relationship, but
did provide IDs, Ember Data would attempt to get all the records in one request.
For example:
// Given this payload:
{
"author": {
"id": "1",
"name": "Lon Ingram",
"post_ids": ["1", "2", "3"]
}
}
this.store.getById('author', '1').get('posts');
// $.ajax GET /posts?ids[]=1&ids[]=2&ids[]=3
Unless you opt in, Ember Data will instead fire 3 requests:
this.store.getById('author', '1').get('posts');
// $.ajax GET /posts/1
// $.ajax GET /posts/2
// $.ajax GET /posts/3
See the section below on "Coalescing Find Requests" for more information.
New Features and Improvements
Embedded Records Mixin
Deserializing Relationships
Thanks to Igor Terzic, Brendan Mcloughlin, and Bill Heaton, the DS.EmbeddedRecordsMixin was extracted out of DS.ActiveModelSerializer in Ember Data v1.0.0-beta.8 so that users of JSONSerializer, RESTSerializer, and ActiveModelSerializer could easily serialize and deserialize relationships. To use the code in your app, you can include the EmbeddedRecordsMixin into your serializer:
App.PostSerializer = DS.RESTSerializer.extend(DS.EmbeddedRecordsMixin);
This means that your PostSerializer will now correctly bring in data for
relationships if they are embedded in the response, rather than sideloaded.
For example, here is the previous JSON data response Ember Data expected for the
RESTAdapter:
// GET /posts/1
{
"post": {
"id": "1",
"name": "The Mother We Share Lyrics",
"authorId": "1"
},
"authors": [
{
"id": "1",
"name": "CHVRCHES"
}
]
}
this.store.find('post', '1').then(function(post){
console.log(post.get('author.name')); // => CHVRCHES
});
Now, if you mixin the EmbeddedRecordsMixin, Ember Data will understand the
following payload:
// GET /posts/1
{
"post": {
"id": "1",
"name": "The Mother We Share Lyrics",
"author": {
"id": "1",
"name": "CHVRCHES"
}
}
}
this.store.find('post', '1').then(function(post) {
console.log(post.get('author.name')); // => CHVRCHES
});
These settings are configurable. See the section below on "Serializing
Relationships."
Serializing Relationships
The EmbeddedRecordsMixin also has support for sending information about
relationships to the server. To override the defaults, you can configure the
EmbeddedRecordsMixin by defining an attrs object on your serializer
definition. For example, to serialize the complete record when serializing to
the server:
App.PostSerializer = DS.RESTSerializer.extend(DS.EmbeddedRecordsMixin, {
attrs: {
author: {
serialize: 'records'
}
}
});
var post = this.store.getById('post', '1');
post.set('name', 'Recover Lyrics');
post.save();
// POST /posts/1
{
"post": {
"name": "Recover Lyrics",
"author": {
"id": "1",
"name": "CHVRCHES"
}
}
}
To see even more ways to customize serializing and deserializing behavior, check
out the documentation for the EmbeddedRecordsMixin.
Coalescing Find Requests
One feature we're particularly excited about is the ability to coalesce find
requests for the same record type.
To introduce this feature, I'll explain the basic concept behind Ember.js's "Run
Loop". Typically in JavaScript code that re-renders whenever the data changes,
changing the data multiple times within the same turn of the JavaScript event
loop would cause multiple re-renders. Ember uses a microlibrary called
Backburner to reduce the number of writes by only rendering once
per "run loop". For more information, you can view the README on the Backburner
on the repository and view the Ember.js Run Loop Guide.
Without "Coalescing Find Requests" turned on, the previous code would result in
multiple network requests:
this.store.find('post', '1');
this.store.find('post', '2');
this.store.find('post', '3');
// $.ajax GET /posts/1
// $.ajax GET /posts/2
// $.ajax GET /posts/3
On the server-side, this is frequently referred to as an N+1
query.
By coalescing (also known as batching) these requests, Ember Data will observe
that you requested several records of the same type and only send one request
instead of 3.
this.store.find('post', '1');
this.store.find('post', '2');
this.store.find('post', '3');
// $.ajax GET /posts?ids[]=1&ids[]=2&ids[]=3
Coalescing find requests is currently turned off by default. To turn it on,
you can use the following code:
DS.RESTAdapter.reopen({
coalesceFindRequests: true
});
To override how the records are requested, you may override the findMany and
findHasMany methods on your adapter.
Ember Inflector is Now a Standalone Package
Ember Inflector is Ember's approach for a Rails-compatible API for inflecting
strings. This provides methods such as Ember.String.pluralize and
Ember.String.singularize, and hooks for defining your own inflections.
Previously, the Ember Inflector package was contained in Ember Data's repository
and released alongside Ember Data. It has been pulled out to a separate
repository. Although Ember Inflector is still included in the
Ember Data release, you may now use it in projects that do not use Ember Data.
Ember Inflector is currently released as a 1.0 semver package.
Ember Inflector String Caching
Ember Inflector now caches lookups of strings by default. This means that you
should only pay the cost of transforming a string (via pluralize and
singularize) once as the values are now stored using an in-memory cache. If
you have memory concerns, you may want to monitor lookups and disable the cache
by calling Ember.Inflector.inflector.disableCache() at the beginning of your
app code.
Improved Uncountable / Irregular Definitions for Singularize
We would like to express our deep appreciation to Olivia Briggs
for adding better support for uncountable/irregular singular words in
Ember-Inflector. You should now not need definitions for dasherized and
underscore versions of your inflections.
Handlebars Helpers for Inflections
You can now use pluralize and singularize in your Handlebars templates:
{{pluralize "octopus"}}
{{singularize "oxen"}}
The Handlebars helpers are bound, so they will stay up to date if you bind to a
property:
{{pluralize type}}
Performance Improvements
Thanks to Stefan Penner from the Ember.js core team, your apps should be
faster when used with Ember Data. We'd also like you to try out Ember 1.8
beta in your apps with Ember Data 1.0.0-beta.9 for additional performance
improvements.
We have more performance improvements around the corner! Keep an eye out for
Stef landing some commits on improving pushPayload calls and a commit
to Backburner improving many hot code paths in Ember Data.
Better Support for Nested Records.
buildURL now takes a record, on which you can look up the relationship if you
need to build a nested URL. For example:
App.CommentAdapter = DS.RestAdapter.extend({
buildURL: function(type, id, record) {
return '/posts/' + record.get('post.id') + '/comments/' + id;
}
})
Added support for preloading records
For more information, go to Store documentation.
Special Thanks
We'd like to thank the following members of the Ember.js community for their
continued contributions to Ember Data:
- Igor Terzic as the project's main contributor (@terzicigor)
- Brendan McLoughlin (@BezoMaxo) for responding to and triaging issues, and
contributing documentation, bug fixes, and improvements. - Ilya Radchenko (@knownasilya)
- Bradley Priest (@bradleypriest)
- Bill Heaton (@pixelhandler)
- Paul Chavard (@tchak)
- Sylvain Mina (GH @sly7-7)
- Ryunosuke Sato (@tricknotes)
- Alexandre de Oliveira (@kurko) for his awesome work on the
ember-localstorage-adapter and
ember-indexeddb-adapter. - Jonathan Collins (Github @jcollins1991)
- Stefan Penner (@stefanpenner)
- Tom Dale (@tomdale)
- Yehuda Katz (@wycats)
We’d also like to thank Instructure and PrecisionNutrition for sponsoring
some of Igor’s development on Ember Data.
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