# Grape::Rabl

Use [Rabl](https://github.com/nesquena/rabl) templates in [Grape](https://github.com/intridea/grape)!

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## Installation

Add the `grape` and `grape-rabl` gems to Gemfile.

```ruby
gem 'grape'
gem 'grape-rabl'
```

And then execute:

    $ bundle

## Usage

### Setup view root directory

```ruby
# config.ru
use Rack::Config do |env|
  env['api.tilt.root'] = '/path/to/view/root/directory'
end
```

### Tell your API to use Grape::Formatter::Rabl

```ruby
class API < Grape::API
  format :json
  formatter :json, Grape::Formatter::Rabl
end
```

### Use rabl templates conditionally

Add the template name to the API options.

```ruby
get "/user/:id", :rabl => "user.rabl" do
  @user = User.find(params[:id])
end
```

You can use instance variables in the Rabl template.

```ruby
object @user => :user
attributes :name, :email

child @project => :project do
  attributes :name
end
```

### Use rabl layout

Gape-rabl first looks for a layout file in `#{env['api.tilt.root']}/layouts/application.rabl`.

You can override the default layout conventions:

```ruby
# config.ru
use Rack::Config do |env|
  env['api.tilt.root'] = '/path/to/view/root/directory'
  env['api.tilt.layout'] = 'layouts/another'
end
```

### Enable template caching

Grape-rabl allows for template caching after templates are loaded initially.

You can enable template caching:

```ruby
# config.ru
Grape::Rabl.configure do |config|
  config.cache_template_loading = true # default: false
end
```

## You can omit .rabl

The following are identical.

```ruby
get "/home", :rabl => "view"
get "/home", :rabl => "view.rabl"
```

### Example

```ruby
# config.ru
use Rack::Config do |env|
  env['api.tilt.root'] = '/path/to/view/root/directory'
end

class UserAPI < Grape::API
  format :json
  formatter :json, Grape::Formatter::Rabl

  get '/user/:id' do
    @user = User.find(params[:id])

    # use rabl with 'user.rabl' or 'admin.rabl' template
    if @user.admin?
      # pass locals with the #render method
      render rabl: 'admin', locals: { details: 'this user is an admin' }
    else
      render rabl: 'user'
    end
  end

  get '/admin/:id', :rabl => 'admin' do
    @user = User.find(params[:id])

    # use rabl with 'super_admin.rabl'
    render rabl: 'super_admin' if @user.super_admin?
    # when render method has not been used use template from endpoint definition
  end

  # use rabl with 'user_history.rabl' template
  get '/user/:id/history', :rabl => 'user_history' do
    @history = User.find(params[:id]).history
  end

  # do not use rabl, fallback to the defalt Grape JSON formatter
  get '/users' do
    User.all
  end
end
```

```ruby
# user.rabl
object @user => :user

attributes :name
```

## Usage with rails

Create grape application

```ruby
# app/api/user.rb
class MyAPI < Grape::API
  format :json
  formatter :json, Grape::Formatter::Rabl
  get '/user/:id', :rabl => "user" do
    @user = User.find(params[:id])
  end
end
```

```ruby
# app/views/api/user.rabl
object @user => :user
```

Edit your **config/application.rb** and add view path

```ruby
# application.rb
class Application < Rails::Application
  config.middleware.use(Rack::Config) do |env|
    env['api.tilt.root'] = Rails.root.join "app", "views", "api"
  end
end
```

Mount application to rails router

```ruby
# routes.rb
GrapeExampleRails::Application.routes.draw do
  mount MyAPI , :at => "/api"
end
```

## Specs

See ["Writing Tests"](https://github.com/intridea/grape#writing-tests) in [https://github.com/intridea/grape](grape) README.

Enjoy :)

## Contributing

See [CONTRIBUTING](CONTRIBUTING.md).

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