# Ember CLI Rails

Ember CLI Rails is an integration story between (surprise surprise) Ember CLI and
Rails 3.1 and up. It is designed to provide an easy way to organize your Rails backed
Ember CLI application with a specific focus on upgradeability. Rails and Ember
[slash Ember CLI] are maintained by different teams with different goals. As
such, we believe that it is important to ensure smooth upgrading of both
aspects of your application.

A large contingent of Ember developers use Rails. And Rails is awesome. With
the upcoming changes to Ember 2.0 and the Ember community's desire to unify
around Ember CLI it is now more important than ever to ensure that Rails and
Ember CLI can coexist and development still be fun!

To this end we have created a minimum set of features (which we will outline
below) to allow you keep your Rails workflow while minimizing the risk of
upgrade pain with your Ember build tools.

For example, end-to-end tests with frameworks like Cucumber should just work.
You should still be able leverage the asset pipeline, and all the conveniences
that Rails offers. And you should get all the new goodies like ES6 modules and
Ember CLI addons too! Without further ado, let's get in there!

## Installation

Firstly, you'll have to include the gem in your `Gemfile` and `bundle install`

```ruby
gem "ember-cli-rails"
```

Then you'll want to configure your installation by adding an `ember.rb`
initializer. There is a generator to guide you, run:

```shell
rails generate ember-cli:init
```

This will generate an initializer that looks like the following:

```ruby
EmberCLI.configure do |c|
  c.app :frontend
end
```

##### options

- `app` - this represents the name of the Ember CLI application.

- `build_timeout` - seconds to allow Ember to build the application before
  timing out

- `path` - the path where your Ember CLI application is located. The default
  value is the name of your app in the Rails root.

- `enable` - a lambda that accepts each request's path. The default value is a
  lambda that returns `true`.

```ruby
EmberCLI.configure do |c|
  c.app :adminpanel # path is "<your-rails-root>/adminpanel"
  c.app :frontend,
    path: "/path/to/your/ember-cli-app/on/disk",
    enable: -> path { path.starts_with?("/app/") }
end
```

Once you've updated your initializer to taste, install Ember CLI if it is not already installed, and use it to generate your Ember CLI app in the location/s specified in the initializer. For example:

```sh
cd frontend
ember init
```

You will also need to install the [ember-cli-rails-addon](https://github.com/rondale-sc/ember-cli-rails-addon). For each of your Ember CLI applications, run:

```sh
npm install --save-dev ember-cli-rails-addon@0.0.13
```

And that's it! You should now be able to start up your Rails server and see your Ember CLI app.

### Multiple Ember CLI apps

In the initializer you may specify multiple Ember CLI apps, each of which can be
referenced with the view helper independently. You'd accomplish this like so:

```ruby
EmberCLI.configure do |c|
  c.app :frontend
  c.app :admin_panel, path: "/somewhere/else"
end
```

## Usage

First, specify in your controller that you don't want to render the layout
(since EmberCLI's `index.html` is a fully-formed HTML document):

```rb
# app/controllers/application.rb
class ApplicationController < ActionController::Base
  def index
    render layout: false
  end
end
```

To render the EmberCLI generated `index.html` into the view,
use the `include_ember_index_html` helper:


```erb
<!-- /app/views/application/index.html.erb -->
<%= include_ember_index_html :frontend %>
```

To inject markup into page, pass in a block that accepts the `head`, and
(optionally) the `body`:

```erb
<!-- /app/views/application/index.html.erb -->
<%= include_ember_index_html :frontend do |head| %>
  <% head.append do %>
    <%= csrf_meta_tags %>
  <% end %>
<% end %>
```

The asset paths will be replaced with asset pipeline generated paths.

*NOTE*

This helper **requires** that the `index.html` file exists.

If you see `Errno::ENOENT` errors in development, your requests are timing out
before EmberCLI finishes compiling the application.

To prevent race conditions, increase your `build_timeout` to ensure that the
build finishes before your request is processed.

### Rendering the EmberCLI generated JS and CSS

In addition to rendering the EmberCLI generated `index.html`, you can inject the
`<script>` and `<link>` tags into your Rails generated views:

```erb
<!-- /app/views/application/index.html.erb -->
<%= include_ember_script_tags :frontend %>
<%= include_ember_stylesheet_tags :frontend %>
```

### Other routes

Rendering Ember applications at routes other than `/` requires additional setup to avoid an Ember `UnrecognizedURLError`.

For instance, if you had Ember applications named  `:frontend` and `:admin_panel` and you wanted to serve them at `/frontend` and `/admin_panel`, you would set up the following Rails routes:

```rb
# /config/routes.rb
Rails.application.routes.draw do
  root 'application#index'
  get  'frontend'    => 'frontend#index'
  get  'admin_panel' => 'admin_panel#index'
end

# /app/controllers/frontend_controller.rb
class FrontendController < ActionController::Base
  def index
    render :index
  end
end

# /app/controllers/admin_panel_controller.rb
class AdminPanelController < ActionController::Base
  def index
    render :index
  end
end
```

Additionally, you would have to modify each Ember app's `baseURL` to point to the correct route:

```javascript
/* /app/frontend/config/environment.js */
module.exports = function(environment) {
  var ENV = {
    modulePrefix: 'frontend',
    environment: environment,
    baseURL: '/frontend', // originally '/'
    ...
  }
}

/* /app/admin_panel/config/environment.js */
module.exports = function(environment) {
  var ENV = {
    modulePrefix: 'admin_panel',
    environment: environment,
    baseURL: '/admin_panel',  // originally '/'
    ...
  }
}
```
Lastly, you would configure each app's `router.js` file so that `rootURL` points to the `baseURL` you just created:

```javascript
/* app/frontend/app/router.js */
var Router = Ember.Router.extend({
  rootURL:  config.baseURL, // add this line
  location: config.locationType
});
```
Repeat for `app/admin_panel/app/router.js`. Now your Ember apps will render properly at the alternative routes.

## CSRF Tokens

Your Rails controllers, by default, are expecting a valid authenticity token to be submitted with non-`GET` requests.
Without it you'll receive a `422 Unprocessable Entity` error, specifically: `ActionController::InvalidAuthenticityToken`.

In order to add that token to your requests, you need to add into your template:

```erb
<!-- /app/views/application/index.html.erb -->
# ... your ember script and stylesheet includes ...
<%= csrf_meta_tags %>
```

This will add the tokens to your page.

You can then override the application `DS.RESTAdapter` (or whatever flavor of adapter you're using) to send that token with the requests:

```js
// path/to/your/ember-cli-app/app/adapters/application.js
import DS from 'ember-data';
import $ from 'jquery';

export default DS.RESTAdapter.extend({
  headers: {
    "X-CSRF-Token": $('meta[name="csrf-token"]').attr('content')
  }
});
```

## Ember Test Suite

To run an Ember app's tests in a browser, mount the `EmberCLI::Engine`:

```ruby
# config/routes.rb

Rails.application.routes.draw do
  mount EmberCLI::Engine => "ember-tests" if Rails.env.development?

  root "application#index"
end
```

Ember tests are served based on the route you mount the Engine on (in this
example, `/ember-tests`) and the name of the Ember app.

For example, to view tests of the `frontend` app, visit
`http://localhost:3000/ember-tests/frontend`.

## Serving from multi-process servers in development

If you're using a multi-process server ([Puma], [Unicorn], etc.) in development,
make sure it's configured to run a single worker process.

Without restricting the server to a single process, [it is possible for multiple
EmberCLI runners to clobber each others' work][#94].

[Puma]: https://github.com/puma/puma
[Unicorn]: https://rubygems.org/gems/unicorn
[#94]: https://github.com/thoughtbot/ember-cli-rails/issues/94#issuecomment-77627453

## Enabling LiveReload

In order to get LiveReload up and running with Ember CLI Rails, you can install
[guard](https://github.com/guard/guard) and
[guard-livereload](https://github.com/guard/guard-livereload) gems, run `guard
init` and then add the following to your `Guardfile`.

```ruby
guard "livereload" do
  # ...
  watch %r{your-appname/app/\w+/.+\.(js|hbs|html|css|<other-extensions>)}
  # ...
end
```

This tells Guard to watch your Ember CLI app for any changes to the JavaScript,
Handlebars, HTML, or CSS files within `app` path. Take note that other
extensions can be added to the line (such as `coffee` for CoffeeScript) to
watch them for changes as well.

*NOTE:* Ember CLI creates symlinks in `your-appname/tmp` directory, which cannot
 be handled properly by Guard. This might lead to performance issues on some
 platforms (most notably on OSX), as well as warnings being printed by latest
 versions of Guard. As a work-around, one might use
 [`directories`](https://github.com/guard/guard/wiki/Guardfile-DSL---Configuring-Guard#directories)
 option, explicitly specifying directories to watch, e.g. adding the following
 to the `Guardfile`.

```ruby
# also add directories that need to be watched by other guard plugins
directories %w[app config lib spec your-appname/app]
```

## Heroku

To configure your Ember CLI Rails app to be ready to deploy on Heroku:

1. Run `rails g ember-cli:heroku` generator
1. [Add the NodeJS buildpack][buildpack] and configure NPM to include the
   `bower` dependency's executable file.

```sh
$ heroku buildpacks:clear
$ heroku buildpacks:add --index 1 https://github.com/heroku/heroku-buildpack-nodejs
$ heroku buildpacks:add --index 2 https://github.com/heroku/heroku-buildpack-ruby
$ heroku config:set NPM_CONFIG_PRODUCTION=false
$ heroku config:unset SKIP_EMBER
```

You should be ready to deploy.

**NOTE** Run the generator each time you introduce additional EmberCLI
applications into the project.

[buildpack]: https://devcenter.heroku.com/articles/using-multiple-buildpacks-for-an-app#adding-a-buildpack

## Capistrano

To deploy an EmberCLI-Rails application with Capistrano, make sure your
EmberCLI app's `package.json` file includes the `bower` package as a development
dependency:

```json
{
  "devDependencies": {
    "bower": "*"
  }
}
```

## Experiencing Slow Build/Deploy Times?
Remove `ember-cli-uglify` from your `package.json` file, and run
`npm remove ember-cli-uglify`. This will improve your build/deploy
time by about 10 minutes.

The reason build/deploy times were slow is because ember uglified the JS and
then added the files to the asset pipeline. Rails would then try and uglify
the JS again, and this would be considerably slower than normal.

See also the note on [Javascript minification](#javascript-minification)

## JavaScript minification

When pre-compiling assets in production, you will want to
ensure that you are not minifying your JavaScript twice: once with EmberCLI's
build tools and once with the Asset Pipeline. Repeated minification is wasteful
and can increase deployment times exponentially.

You can either disable minification in your EmberCLI application's
`ember-cli-build.js`:

```javascript
/* global require, module */
var EmberApp = require('ember-cli/lib/broccoli/ember-app');

module.exports = function(defaults) {
  var app = new EmberApp({
    minifyJS: false,
  });

  // ...
};
```

or in your Rails application's `config/environments/production.rb`:

```ruby
Rails.application.configure do
  config.assets.js_compressor = nil
end
```

## Additional Information

When running in the development environment, Ember CLI Rails runs `ember build`
with the `--output-path` and `--watch` flags on. The `--watch` flag tells
Ember CLI to watch for file system events and rebuild when an Ember CLI file is
changed. The `--output-path` flag specifies where the distribution files will
be put. Ember CLI Rails does some fancy stuff to get it into your asset path
without polluting your git history. Note that for this to work, you must have
`config.consider_all_requests_local = true` set in
`config/environments/development.rb`, otherwise the middleware responsible for
building Ember CLI will not be enabled.

Alternatively, if you want to override the default behavior in any given Rails
environment, you can manually set the `config.use_ember_middleware` and
`config.use_ember_live_recompilation` flags in the environment-specific config
file.

### `RAILS_ENV`

While being managed by EmberCLI Rails, EmberCLI process will have
access to the `RAILS_ENV` environment variable. This can be helpful to detect
the Rails environment from within the EmberCLI process.

This can be useful to determine whether or not EmberCLI is running in its own
standalone process or being managed by Rails.

For example, to enable [ember-cli-mirage][ember-cli-mirage] API responses in
`development` while being run outside of Rails (while run by `ember serve`),
check for the absence of the `RAILS_ENV` environment variable:

```js
// config/environment.js
if (environment === 'development') {
  ENV['ember-cli-mirage'] = {
    enabled: typeof process.env.RAILS_ENV === 'undefined',
  }
}
```

`RAILS_ENV` will be absent in production builds.

[ember-cli-mirage]: http://ember-cli-mirage.com/docs/latest/

### `SKIP_EMBER`

To disable asset compilation entirely, set an environment variable
`SKIP_EMBER=1`.

This can be useful when an application's frontend is developed locally with
EmberCLI-Rails, but deployed separately (for example, with
[ember-cli-deploy][ember-cli-deploy]).

[ember-cli-deploy]: https://github.com/ember-cli/ember-cli-deploy

#### Ember Dependencies

Ember has several dependencies. Some of these dependencies might already be
present in your asset list. For example jQuery is bundled in `jquery-rails` gem.
If you have the jQuery assets included on your page you may want to exclude them
from the Ember distribution. You can do so by setting the `exclude_ember_deps`
option like so:

```ruby
EmberCLI.configure do |c|
  c.app :frontend, exclude_ember_deps: "jquery"
  c.app :admin_panel, exclude_ember_deps: ["jquery", "handlebars"]
end
```

jQuery and Handlebars are the main use cases for this flag.

## Ruby and Rails support

This project supports:

* Ruby versions `>= 2.1.0`
* Rails `3.2.x` and `>=4.1.x`.

To learn more about supported versions and upgrades, read the [upgrading guide].

[upgrading guide]: /UPGRADING.md

## Contributing

See the [CONTRIBUTING] document.
Thank you, [contributors]!

  [CONTRIBUTING]: CONTRIBUTING.md
  [contributors]: https://github.com/thoughtbot/ember-cli-rails/graphs/contributors

## License

Open source templates are Copyright (c) 2015 thoughtbot, inc.
It contains free software that may be redistributed
under the terms specified in the [LICENSE] file.

[LICENSE]: /LICENSE.txt

## About

ember-cli-rails was originally created by
[Pavel Pravosud][rwz] and
[Jonathan Jackson][rondale-sc].

ember-cli-rails is maintained by [Sean Doyle][seanpdoyle] and [Jonathan
Jackson][rondale-sc].

[rwz]: https://github.com/rwz
[rondale-sc]: https://github.com/rondale-sc
[seanpdoyle]: https://github.com/seanpdoyle

![thoughtbot](https://thoughtbot.com/logo.png)

ember-cli-rails is maintained and funded by thoughtbot, inc.
The names and logos for thoughtbot are trademarks of thoughtbot, inc.

We love open source software!
See [our other projects][community]
or [hire us][hire] to help build your product.

  [community]: https://thoughtbot.com/community?utm_source=github
  [hire]: https://thoughtbot.com/hire-us?utm_source=github