Apical

Elixir Routers from OpenAPI schemas

Installation

This package can be installed by adding apical to your list of dependencies in mix.exs:

Exonerate is a compile-time dependency. If you don't include this in your Mix.exs, there will be unwanted compiler warnings.

def deps do
  [
     {:apical, "~> 0.2.1"},
     {:exonerate, "~> 1.1.2", runtime: Mix.env() != :prod}
  ]
end

If you think you might need to recompile your router in production, remove the runtime option on Exonerate.

Basic use

For the following router module:

defmodule MyProjectWeb.ApiRouter do
    require Apical

    Apical.router_from_string(
      """
      openapi: 3.1.0
      info:
        title: My API
        version: 1.0.0
      paths:
        "/":
          get:
            operationId: getOperation
            responses:
              "200":
                description: OK
      """,
      controller: MyProjectWeb.ApiController,
      encoding: "application/yaml"
    )
end

You would connect this to your endpoint as follows:

defmodule MyProjectWeb.ApiEndpoint do
  use Phoenix.Endpoint, otp_app: :my_project

  plug(MyProjectWeb.ApiRouter)
end

And compose a controller as follows:

defmodule MyProjectWeb.ApiController do
  use Phoenix.Controller

  alias Plug.Conn

  # NOTE THE CASING BELOW:
  def getOperation(conn, _params) do
    Conn.send_resp(conn, 200, "OK")
  end
end

From file:

You may also generate a router from a file:

defmodule MyProjectWeb.ApiRouter do
    require Apical

    Apical.router_from_file("priv/assets/api/openapi.v1.yaml",
      controller: MyProjectWeb.ApiController
    )
end

Embedding inside of an existing router

You may also embed apical inside of an existing phoenix router:

scope "/api", MyProjectWeb.Api do
  require Apical

  Apical.router_from_file("priv/assets/api/openapi.v1.yaml",
    controller: MyProjectWeb.ApiController)
end

If you are embedding Apical in an existing router, be sure to delete the following lines from the phoenix endpoint:

plug Plug.Parsers,
  parsers: [:urlencoded, :multipart, :json],
  pass: ["*/*"],
  json_decoder: Phoenix.json_library()

As Apical will do its own parsing.

Using it in tests:

If you're using OpenAPI as a client, you can use Apical to test that your request wrapper conforms to the client schema:

https://hexdocs.pm/apical/apical-for-testing.html

Advanced usage

For more advanced usage, consult the tests in the test directory. Guides will be provided in the next version of apical

Documentation

Documentation can be found at https://hexdocs.pm/apical.