Behaviour for action middleware.

Middlewares are called before and after action execution, allowing you to modify the request map or response.

Before Middleware

Receives the request map, must return a (possibly modified) request map.

defmodule MyApp.Middleware.DBLink do
  @behaviour Mooncore.Middleware

  @impl true
  def call(req) do
    db = MyApp.DB.link(req[:auth]["dkey"])
    Map.put(req, :db, db)
  end
end

After Middleware

Receives the response from the action handler, must return a (possibly modified) response.

defmodule MyApp.Middleware.StripPassword do
  @behaviour Mooncore.Middleware

  @impl true
  def call(response) when is_map(response) do
    Map.delete(response, "password")
  end
  def call(response), do: response
end

Configure in:

config :mooncore,
  before_action: [MyApp.Middleware.DBLink],
  after_action: [MyApp.Middleware.StripPassword]