# ember-rails  [![Build Status](https://secure.travis-ci.org/emberjs/ember-rails.png?branch=master)](http://travis-ci.org/emberjs/ember-rails) [![Dependency Status](https://gemnasium.com/emberjs/ember-rails.png)](https://gemnasium.com/emberjs/ember-rails)

ember-rails allows you to include [Ember.JS](http://emberjs.com/) 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](https://github.com/keithpitt/ember-rails-example). There is also a great tutorial by [Dan Gebhardt](https://twitter.com/#!/dgeb) called "[Beginning Ember.js on Rails](http://www.cerebris.com/blog/2012/01/24/beginning-ember-js-on-rails-part-1/)" which is a great read if you're just starting out with Rails and Ember.js

## Getting started
1. Add the gem to your application Gemfile:
```ruby
gem 'ember-rails'
gem 'ember-source', '1.0.0.rc4' # or the version you need
gem 'handlebars-source', '1.0.0.rc4' # or the version you need
```

2. Run `bundle install`

3. [Optional] Configure the ember variant in your environment files (i.e. development.rb, production.rb). If you don't configure this, the version of Ember used defaults to development when the Rails environment is development, and similarly for production.
```ruby
  config.ember.variant = :development # or :production
```

4. Next, generate the application structure:
```shell
bundle exec rails generate ember:bootstrap
```

5. Restart your server (if it's running)


Notes:

To install the latest builds of ember and ember-data:
```shell
bundle exec rails generate ember:install --head
```

## For CoffeeScript support
1. Add coffee-rails to the Gemfile
```ruby
gem 'coffee-rails'
```

2. Run the bootstrap generator in step 4 with an extra flag instead:
```sh
rails g ember:bootstrap -g --javascript-engine coffee
```

## 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`.

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:
        <button {{action anActionName}}>OK</button>

It will be translated as :

    <script type="text/x-handlebars">
        <button {{action anActionName}}>OK</button>
    </script>

## Specifying Different Versions of Ember/Handlebars/Ember-Data

![Ember Data Warning](ember-data-in-progress.png)
By default, ember-rails ships with the latest version of
[Ember](https://rubygems.org/gems/ember-source/versions),
[Handlebars](https://rubygems.org/gems/handlebars-source/versions),
and [Ember-Data](https://rubygems.org/gems/ember-data-source/versions).

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 `require`d 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

## Updating Ember

If at any point you need to update Ember.js from master, you can do that with

    rails generate ember:install --head

This will fetch both Ember.js and Ember Data from [http://builds.emberjs.com/](http://builds.emberjs.com/) and copy to the right directory.

## 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.