- Extended by:
- AbstractController::Rendering, HideActions, ActionView::Rendering, StrongParameters
- Defined in:
API Controller is a lightweight version of
ActionController::Base, created for applications that don't require all functionality that a complete Rails controller provides, allowing you to create faster controllers for example for API only applications.
An API Controller is different from a normal controller in the sense that by default it doesn't include a number of features that are usually required by browser access only: layouts and templates rendering, cookies, sessions, flash, assets, and so on. This makes the entire controller stack thinner and faster, suitable for API applications. It doesn't mean you won't have such features if you need them: they're all available for you to include in your application, they're just not part of the default API Controller stack.
By default, only the ApplicationController in a Rails application inherits from
ActionController::API. All other controllers in turn inherit from ApplicationController.
A sample controller could look like this:
class PostsController < ApplicationController def index @posts = Post.all render json: @posts end end
Request, response and parameters objects all work the exact same way as
The default API Controller stack includes all renderers, which means you can use
render :json and brothers freely in your controllers. Keep in mind that templates are not going to be rendered, so you need to ensure your controller is calling either
redirect in all actions.
def show @post = Post.find(params[:id]) render json: @post end
Redirects are used to move from one action to another. You can use the
redirect method in your controllers in the same way as
ActionController::Base. For example:
def create redirect_to root_url and return if # do stuff here end
Adding new behavior
In some scenarios you may want to add back some functionality provided by
ActionController::Base that is not present by default in
ActionController::API, for instance
MimeResponds. This module gives you the
respond_with methods. Adding it is quite simple, you just need to include the module in a specific controller or in
ApplicationController in case you want it available to your entire app:
class ApplicationController < ::API include ::MimeResponds end class PostsController < ApplicationController respond_to :json, :xml def index @posts = Post.all respond_with @posts end end
Quite straightforward. Make sure to check
ActionController::Base available modules if you want to include any other functionality that is not provided by
ActionController::API out of the box.
Defined Under Namespace
Constant Summary collapse
- MODULES =
[ UrlFor, Redirecting, Rendering, Renderers::All, ConditionalGet, RackDelegation, ForceSSL, DataStreaming, # Before callbacks should also be executed the earliest as possible, so # also include them at the bottom. AbstractController::Callbacks, # Append rescue at the bottom to wrap as much as possible. Rescue, # Add instrumentations hooks at the bottom, to ensure they instrument # all the methods properly. Instrumentation ]
- DEFAULT_PROTECTED_INSTANCE_VARIABLES =
begin if ::VERSION::MAJOR == 5 || (::VERSION::MAJOR == 4 && ::VERSION::MINOR > 0) Set else Array end end.new
Class Method Summary collapse
- .protected_instance_variables ⇒ Object
.without_modules(*modules) ⇒ Object
Shortcut helper that returns all the ActionController::API modules except the ones passed in the argument:.
Methods included from
, , , , , , , , , , , , ,
Class Method Details
.protected_instance_variables ⇒ Object
169 170 171
# File 'lib/rails-api/action_controller/api.rb', line 169 def self.protected_instance_variables end
.without_modules(*modules) ⇒ Object
Shortcut helper that returns all the ActionController::API modules except the ones passed in the argument:
class MetalController ::.without_modules(:Redirecting, :DataStreaming).each do |left| include left end end
This gives better control over what you want to exclude and makes it easier to create an api controller class, instead of listing the modules required manually.
117 118 119 120 121 122 123
# File 'lib/rails-api/action_controller/api.rb', line 117 def self.without_modules(*modules) modules = modules.map do |m| m.is_a?(Symbol) ? .const_get(m) : m end - modules end