Process requests and render responses.

Options

None.

Usage

The use Orbit.Controller macro injects the following into the module:

@behaviour Orbit.Pipe
def call(request, arg)
def action(request, action) # overridable

The call/2 function implements the Orbit.Pipe callback, making the controller behave like any other pipe. The arg is the action name, as an atom, and is set to the :action assign. Any pipe/2 definitions in this controller are called first, and then action/2 is called.

Overriding action/2

The action/2 function is overridable. It's an easy way to extend the controller's default behavior, or to customize the signature of the action functions to something other than action_name(req, params). Its default implementation is:

def action(req, action) do
  apply(__MODULE__, action, [req, req.params])
end

Views

A controller can render responses directly in the controller action, or defer the rendering to an external view module. Define the view/1 pipe to set the view template based on the controller action name.

  view MyApp.MyView

  def index(req, _params) do
    render(req) # => MyApp.MyView.index(req.assigns)
  end

Layouts

Layouts are simply templates that are provided an @inner_content assign which contains the content of the child view to render within the layout.

def outer_layout(assigns) do
  ~G"""
  begin outer
  <%= @inner_content %>
  end outer
  """
end

req
|> put_layout(&outer_layout/1)
|> render()

# =>
"""
begin outer
...view...
end outer
"""

Example

# Router
route "/users", MyApp.UserController, :index
route "/users/:id", MyApp.UserController, :show

# Controller
defmodule MyApp.UserController do
  use Orbit.Controller

  view MyApp.UserView

  def index(req, _params), do: ...
  def show(req, %{"id" => id}), do: ...
end