ember-rails

ember-rails allows you to include Ember.JS into your Rails 3.1+ application.

The gem will also pre-compile your handlebars templates when building your asset pipeline. It includes development and production copies of Ember.

You can see an example of how to use the gem here. There is also a great tutorial by Dan Gebhardt called "Beginning Ember.js on Rails" which is a great read if you're just starting out with Rails and Ember.js

Getting started

Add the gem to your application Gemfile:

gem "ember-rails"

Run bundle install and use the ember-rails generator to add the necessary dependencies.

Ember-rails will use the production build of Ember.js when Rails is running in production mode, and the development build otherwise.

Setting Ember Variant

After running bundle install make sure you set the ember variant for your enviroments in their respected files with.

config.ember.variant = :development # or :production

Without doing so will result in Sprockrets not being able to resolve Ember's dependencies.

Architecture

Ember does not require an organized file structure. However, ember-rails allows you to use rails g ember:bootstrap to create the following directory structure under app/assets/javascripts:

controllers/
helpers/
models/
routes/
templates/
views/

Additionally, it will add the following lines to app/assets/javascripts/application.js. By default, it uses the Rails Application's name and creates an rails_app_name.js file to setup application namespace and initial requires:

//= require handlebars
//= require ember
//= require ember-data
//= require_self
//= require rails_app_name
RailsAppName = Ember.Application.create();

Example:

rails g ember:bootstrap
  insert  app/assets/javascripts/application.js
  create  app/assets/javascripts/models
  create  app/assets/javascripts/models/.gitkeep
  create  app/assets/javascripts/controllers
  create  app/assets/javascripts/controllers/.gitkeep
  create  app/assets/javascripts/views
  create  app/assets/javascripts/views/.gitkeep
  create  app/assets/javascripts/helpers
  create  app/assets/javascripts/helpers/.gitkeep
  create  app/assets/javascripts/templates
  create  app/assets/javascripts/templates/.gitkeep
  create  app/assets/javascripts/app.js

If you want to avoid .gitkeep files, use the skip git option like this: rails g ember:bootstrap -g.

(CoffeeScript support: just make sure you have gem 'coffee-rails' in your application Gemfile.)

Ask Rails to serve HandlebarsJS and pre-compile templates to Ember by putting each template in a dedicated ".js.hjs", ".hbs" or ".handlebars" file (e.g. app/assets/javascripts/templates/admin_panel.handlebars) and including the assets in your layout:

<%= javascript_include_tag "templates/admin_panel" %>

If you want to strip template root from template names, add templates_root option to your application configuration block. By default, templates_root is 'templates'.

config.handlebars.templates_root = 'ember_templates'

If you store templates in a file like app/assets/javascripts/ember_templates/admin_panel.handlebars after setting the above config, it will be made available to Ember as the admin_panel template.

(Note: you must clear the local sprockets cache after modifying templates_root, stored by default in tmp/cache/assets)

Default behavior for ember-rails is to precompile handlebars templates. If you don't want this behavior you can turn it off in your application configuration (or per environment in: config/environments/development.rb) block:

config.handlebars.precompile = false

(Note: you must clear the local sprockets cache if you disable precompilation, stored by default in tmp/cache/assets)

Bundle all templates together thanks to Sprockets, e.g create app/assets/javascripts/templates/all.js with:

//= require_tree .

Now a single line in the layout loads everything:

<%= javascript_include_tag "templates/all" %>

If you use Slim or Haml templates, you can use handlebars filter :

handlebars:
    {{#view Ember.Button}}OK{{/view}}

It will be translated as :

<script type="text/x-handlebars">
    {{#view Ember.Button}}OK{{/view}}
</script>

Specifying Different Versions of Ember/Handlebars/Ember-Data

By default, ember-rails ships with the latest version of Ember (rc1), Handlebars (rc3), and Ember-Data.

To specify a different version that'll be used for both template precompilation and serving to the browser, you can specify the desired version of one of the above-linked gems in the Gemfile, e.g.:

gem 'ember-source', '1.0.0.pre4.2'

You can also specify versions of 'handlebars-source' and 'ember-data-source', but note that an appropriate 'handlebars-source' will be automatically chosen depending on the version of 'ember-source' that's specified.

You can also override the specific ember.js, handlebars.js, and ember-data.js files that'll be required by the Asset pipeline by placing these files in vendor/assets/ember/development and vendor/assets/ember/production, depending on the config.ember.variant you've specified in your app's configuration, e.g.:

config.ember.variant = :production
#config.ember.variant = :development

Note on Patches/Pull Requests

1. Fork the project.
2. Make your feature addition or bug fix.
3. Add tests for it. This is important so I don't break it in a future version unintentionally.
4. Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
5. Send me a pull request. Bonus points for topic branches.