ExMvc

Making bootstrapping a RESTful Elixir API easier than ever

While Phoenix provides many CLI tools to expedite the writing of boilerplate code, I felt like there was a need to use metaprogramming to greatly simplify creating model, view, controller, and service layer modules. ExMvc is easy to implement, and flexible. You can override any function, as well as specify exactly what functions you want to generate in a controller!

Please open an issue if you find any bugs or have any ideas to make this package better/more relevant!

Installation

If available in Hex, the package can be installed by adding ex_mvc to your list of dependencies in mix.exs:

def deps do
  [
    {:ex_mvc, "~> 0.3.1"}
  ]
end

Configuration

In your config.exs, configure ExMvc as below. Optional configuration can be done for the fields disallowed in a JSON render. See View for default disallowed fields.

config :ex_mvc, 
  repo: MyApp.Repo, 
  web_namespace: MyAppWeb,
  disallowed_fields: [:__meta__, :password, :another_private_field] # <-- Optional

Implementation

ModelChangeset

The model changeset module provides standard insert changeset and changesets for use by an adapter (or the service layer)

e.g:

defmodule TestApp.User do
  use Ecto.Schema

  schema "table" do
    ...
  end

  use ExMvc.ModelChangeset, req_fields: [:username, :phone], opt_fields: [:avatar_url]
end

Adapter

The adapter is an element of the service layer to help define basic fetch/update/create functionality for a model that uses ModelChangeset.

Associations are preloaded one level deep.

e.g:

defmodule TestApp.Users do
  use ExMvc.Adapter, model: TestApp.User
end

View

The view renders a model in JSON. Any association is rendered with its fields in the object.

By default, View behaves such that it redacts the following fields (called disallowed fields):

• __meta__
• password
• password_hash

Disallowed fields can be set on configuration, using the config: disallowed_fields: [:__meta__, :password, :another_private_field]

e.g:

defmodule TestAppWeb.UserView do
  use ExMvc.View, model: TestApp.User
end

Controller

Controllers generate GET, PUT, POST and DELETE functions for each model, using functionality provided in the adapter and view to functionally return content.

e.g:

defmodule TestAppWeb.UserController do
  use ExMvc.Controller, 
    adapter: TestApp.User, 
    view: TestAppWeb.UserView
end

By default, controllers will create the following functions: show/2, index/2, update/2, create/2, delete/2 This can be controlled using the :only (only create the routes specified) or :except (create all default routes except the following) options.

e.g:

use ExMvc.Controller,
  ...,
  # Either
  only: [:show, :index, :update] # Generates: show/2, index/2, and update/2
  # Or
  except: [:create, :update] # Generates: show/2, index/2, delete/2