# Ember CLI Rails
Unify your EmberCLI and Rails Workflows!
EmberCLI-Rails is designed to give you the best of both worlds:
* Stay up to date with the latest JavaScript technology and EmberCLI addons
* Develop your Rails API and Ember front-ends from within a single process
* Inject Rails-generated content into your EmberCLI application
* Avoid Cross-Origin Resource Sharing gotchas by serving your EmberCLI
applications and your API from a single domain
* Write truly end-to-end integration tests, exercising your application's entire
stack through JavaScript-enabled Capybara tests
* Deploy your entire suite of applications to Heroku with a single `git push`
If you're having trouble, checkout the [example project]!
**EmberCLI-Rails Supports EmberCLI 1.13.13 and later.**
[example project]: https://github.com/seanpdoyle/ember-cli-rails-heroku-example
## Install
Add the following to your `Gemfile`:
```ruby
gem "ember-cli-rails"
```
Then run `bundle install`:
```bash
$ bundle install
```
If you haven't created an Ember application yet, generate a new one:
```bash
$ ember new frontend --skip-git
```
## Setup
First, generate the gem's initializer:
```bash
$ rails generate ember:init
```
This will create the following initializer:
```ruby
# config/initializers/ember.rb
EmberCli.configure do |c|
c.app :frontend
end
```
This initializer assumes that your Ember application exists in
`Rails.root.join("frontend")`.
If this is not the case, you could
* move your existing Ember application into `Rails.root.join("frontend")`
* configure `frontend` to reference the Ember application in its current
directory:
```rb
c.app :frontend, path: "~/projects/my-ember-app"
```
**Initializer options**
- `name` - this represents the name of the Ember CLI application.
- `path` - the path where your Ember CLI application is located. The default
value is the name of your app in the Rails root.
```ruby
EmberCli.configure do |c|
c.app :adminpanel # path defaults to `Rails.root.join("adminpanel")`
c.app :frontend,
path: "/path/to/your/ember-cli-app/on/disk"
end
```
Next, install the [ember-cli-rails-addon][addon]:
```bash
$ cd path/to/frontend
$ ember install ember-cli-rails-addon
```
Be sure that the addon's [`MAJOR` and `MINOR` version][semver] matches the gem's
`MAJOR` and `MINOR` versions.
For instance, if you're using the `0.6.x` version of the gem, specify
`~> 0.6.0` in your Ember app's `package.json`:
```json
{
"devDependencies": {
"ember-cli-rails-addon": "~> 0.6.0"
}
}
```
[addon]: https://github.com/rondale-sc/ember-cli-rails-addon/
[semver]: http://semver.org/
## Mount
Configure Rails to route requests to the `frontend` Ember application:
```rb
# config/routes.rb
Rails.application.routes.draw do
mount_ember_app :frontend, to: "/"
end
```
**Routing options**
* `to` - The path to handle as an Ember application. This will only apply to
`format: :html` requests. Additionally, this will handle child routes as well.
For instance, mounting `mount_ember_app :frontend, to: "/frontend"` will handle a
`format: :html` request to `/frontend/posts`.
* `controller` - Defaults to `"ember_cli/ember"`
* `action` - Defaults to `"index"`
Finally, install your Ember application's dependencies:
```bash
$ rake ember:install
```
Boot your Rails application, navigate to `"/"`, and view your EmberCLI
application!
## Develop
EmberCLI Rails exposes several useful rake tasks.
**`ember:install`**
Install the Ember applications' dependencies.
**`ember:compile`**
Compile the Ember applications.
**`ember:test`**
Execute Ember's test suite.
If you're using Rake to run the test suite, make sure to configure your test
task to depend on `ember:test`.
For example, to configure a bare `rake` command to run both RSpec and Ember test
suites, configure the `default` task to depend on both `spec` and `ember:test`.
```rb
task default: [:spec, "ember:test"]
```
## Deploy
In production environments, assets should be served over a
Content Delivery Network.
Configuring an `ember-cli-rails` application to serve Ember's assets over a CDN
is very similar to [configuring an EmberCLI application to serve assets over a
CDN][ember-cli-cdn]:
[ember-cli-cdn]: http://ember-cli.com/user-guide/#fingerprinting-and-cdn-urls
```js
var app = new EmberApp({
fingerprint: {
prepend: 'https://cdn.example.com/'
}
});
```
If you're serving the Ember application from a path other than `"/"`, the
`prepend` URL must end with the mounted path:
```js
var app = new EmberApp({
fingerprint: {
// for an Ember application mounted to `/admin_panel/`
prepend: 'https://cdn.example.com/admin_panel/',
}
});
```
As long as your [CDN is configured to pull from your Rails application][dns-cdn]
, your assets will be served over the CDN.
[dns-cdn]: https://robots.thoughtbot.com/dns-cdn-origin
### Deployment Strategies
By default, EmberCLI-Rails will serve the `index.html` file that `ember build`
produces.
If you need to override this behavior (for instance, if you're using
[`ember-cli-deploy`'s "Lightning Fast Deployment"][lightning] strategy in
`production`), you can specify the strategy's class in the initializer:
```rb
EmberCli.configure do |config|
config.app :frontend, deploy: { production: EmberCli::Deploy::Redis }
end
```
This example configures the `frontend` Ember application to retrieve the
index's HTML from an [`ember-cli-deploy-redis`][ember-cli-deploy-redis]
-populated Redis entry using the
[`ember-cli-rails-deploy-redis`][ember-cli-rails-deploy-redis] gem.
If you're deploying HTML with a custom strategy in `development` or `test`,
disable EmberCLI-Rails' build step by setting `ENV["SKIP_EMBER"] = true`.
**NOTE:**
Specifying a deployment strategy is only supported for applications that use the
`mount_ember_app` and `render_ember_app` helpers.
[ember-cli-deploy-redis]: https://github.com/ember-cli-deploy/ember-cli-deploy-redis
[ember-cli-rails-deploy-redis]: https://github.com/seanpdoyle/ember-cli-rails-deploy-redis
[lightning]: https://github.com/ember-cli-deploy/ember-cli-deploy-lightning-pack
### Heroku
To configure your EmberCLI-Rails applications for Heroku:
1. Execute `rails generate ember:heroku`
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 are ready to deploy:
```bash
$ git push heroku master
```
**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
EmberCLI-Rails executes both `npm install` and `bower install` during EmberCLI's
compilation, triggered by the `asset:precompilation` rake task.
The `npm` and `bower` executables are required to be defined in the deployment
SSH session's `$PATH`. It is not sufficient to modify the session's `$PATH` in
a `.bash_profile`.
To resolve this issue, prepend the Node installation's `bin` directory to the
target system's `$PATH`:
```ruby
#config/deploy/production.rb
set :default_env, {
"PATH" => "/home/deploy/.nvm/versions/node/v4.2.1/bin:$PATH"
}
```
The system in this example is using `nvm` to configure the node version. If
you're not using `nvm`, make sure the string you prepend to the `$PATH` variable
contains the directory or directories that contain the `bower` and `npm`
executables.
## Override
By default, routes defined by `ember_app` will be rendered with the internal
`EmberCli::EmberController`.
### Overriding the view
The `EmberCli::EmberController` renders the Ember application's `index.html` and
injects the Rails-generated CSRF tags into the ``.
To customize the view, create `app/views/ember_cli/ember/index.html.erb`:
```erb
<%= render_ember_app ember_app do |head| %>
<% head.append do %>
<%= csrf_meta_tags %>
<% end %>
<% end %>
```
The `ember_app` helper is available within the `EmberCli::EmberController`'s
view, and refers to the name of the current EmberCLI application.
To inject the EmberCLI generated `index.html`, use the `render_ember_app`
helper in your view:
```erb
<%= render_ember_app :frontend do |head, body| %>
<% head.append do %>
<%= csrf_meta_tags %>
<% end %>
<% body.append do %>
<%= render partial: "my-analytics" %>
<% end %>
<% end %>
```
The `body` block argument and the corresponding call to `body.append` in the
example are both optional, and can be omitted.
### Overriding the controller
To override this behavior, you can specify [any of Rails' routing options]
[route-options].
[route-options]: http://api.rubyonrails.org/classes/ActionDispatch/Routing/Mapper/Base.html#method-i-match
For the sake of this example, override the `controller` and `action` options:
```rb
# config/routes
Rails.application.routes.draw do
mount_ember_app :frontend, to: "/", controller: "application", action: "index"
end
```
When serving the EmberCLI generated `index.html` with the `render_ember_app`
helper, make sure the controller's `layout` is disabled, as EmberCLI generates a
fully-formed HTML document:
```rb
# app/controllers/application.rb
class ApplicationController < ActionController::Base
def index
render layout: false
end
end
```
### Rendering the EmberCLI generated JS and CSS
Rendering EmberCLI applications with `render_ember_app` is the recommended,
actively supported method of serving EmberCLI applications.
However, for the sake of backwards compatibility, `ember-cli-rails` supports
injecting the EmberCLI-generated assets into an existing Rails layout.
Following the example above, configure the mounted EmberCLI application to be
served by a custom controller (`ApplicationController`, in this case).
In the corresponding view, use the asset helpers:
```erb
<%= include_ember_script_tags :frontend %>
<%= include_ember_stylesheet_tags :frontend %>
```
### Mounting multiple Ember applications
Rendering Ember applications to paths other than `/` requires additional
configuration.
Consider a scenario where you had Ember applications named `frontend` and
`admin_panel`, served from `/` and `/admin_panel` respectively.
First, specify the Ember applications in the initializer:
```ruby
EmberCli.configure do |c|
c.app :frontend
c.app :admin_panel, path: "path/to/admin_ember_app"
end
```
Next, mount the applications alongside the rest of Rails' routes:
```rb
# /config/routes.rb
Rails.application.routes.draw do
mount_ember_app :frontend, to: "/"
mount_ember_app :admin_panel, to: "/admin_panel"
end
```
Then set each Ember application's `baseURL` to the mount point:
```javascript
// frontend/config/environment.js
module.exports = function(environment) {
var ENV = {
modulePrefix: 'frontend',
environment: environment,
baseURL: '/',
// ...
}
};
// path/to/admin_ember_app/config/environment.js
module.exports = function(environment) {
var ENV = {
modulePrefix: 'admin_panel',
environment: environment,
baseURL: '/admin_panel', // originally '/'
// ...
}
};
```
Finally, configure EmberCLI's fingerprinting to prepend the mount point to the
application's assets:
```js
// frontend/ember-cli-build.js
module.exports = function(defaults) {
var app = new EmberApp(defaults, {
fingerprint: {
// matches the `/` mount point
prepend: 'https://cdn.example.com/',
}
});
};
// path/to/admin_ember_app/ember-cli-build.js
module.exports = function(defaults) {
var app = new EmberApp(defaults, {
fingerprint: {
// matches the `/admin_panel` mount point
prepend: 'https://cdn.example.com/admin_panel/',
}
});
};
```
When injecting the EmberCLI-generated assets with the `include_ember_script_tags`
and `include_ember_stylesheet_tags` helpers to a path other than `"/"`, a
`` tag must also be injected with a corresponding `href` value:
```erb
<%= include_ember_script_tags :frontend %>
<%= include_ember_stylesheet_tags :frontend %>
<%= include_ember_script_tags :admin_panel %>
<%= include_ember_stylesheet_tags :admin_panel %>
```
If you're using the `include_ember` style helpers with a single-page Ember
application that defers routing to the Rails application, insert a call to
`mount_ember_assets` at the bottom of your routes file to serve the
EmberCLI-generated assets:
```rb
# config/routes.rb
Rails.application.routes.draw do
mount_ember_assets :frontend, to: "/"
end
```
## CSRF Tokens
Your Rails controllers, by default, expect a valid authenticity token to
be submitted along with non-`GET` requests.
Without the authenticity token, requests will respond with
`422 Unprocessable Entity` errors (specifically
`ActionController::InvalidAuthenticityToken`).
To add the necessary tokens to requests, inject the `csrf_meta_tags` into
the template:
```erb
<%= render_ember_app :frontend do |head| %>
<% head.append do %>
<%= csrf_meta_tags %>
<% end %>
<% end %>
```
The default `EmberCli::EmberController` and the default view handle behave like
this by default.
If an Ember application is mounted with another controller, it should append
the CSRF tags to its view's ``.
[ember-cli-rails-addon][addon] configures your Ember application to make HTTP
requests with the injected CSRF tokens in the `X-CSRF-TOKEN` header.
## 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
## `SKIP_EMBER`
If set on the environment, `SKIP_EMBER` will configure `ember-cli-rails` to skip
the build step entirely. This is useful if you're using an alternative
deployment strategy in the `test` or `development` environment. By default,
`ember-cli-rails` will skip the build step in `production`-like environments.
## `EMBER_ENV`
If set on the environment, the value of `EMBER_ENV` will be passed to the
`ember` process as the value of the `--environment` flag.
If `EMBER_ENV` is unspecified, the current Rails environment will be passed to
the `ember` process, with the exception of non-standard Rails environments,
which will be replaced with `production`.
## `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/
## EmberCLI support
This project supports:
* EmberCLI versions `>= 1.13.13`
## Ruby and Rails support
This project supports:
* Ruby versions `>= 2.1.0`
* Rails versions `>=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
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