Contextual

Contextual provides a macro that will generate your Ecto contexts for you.

Imagine you have a schema called MyApp.Posts.Post. Typically, you'd create a context to encapsulate Ecto access for creating, updating, and deleting posts.

You could use the built-in Phoenix generators to solve this problem, but then you're left with a bunch of boilerplate code that distracts the reader from the actual complexity in your contexts.

Instead, use Contextual and delete a bunch of boilerplate code. Or not, it's entirely your decision.

Installation

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

def deps do
  [{:contextual, "~> 0.1.0"}]
end

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

Creating your context

Here's how you'd define your context:

defmodule MyApp.Posts do
  use Contextual,
    name: {:post, :posts},
    schema: MyApp.Posts.Post,
    repo: MyApp.Repo
end

MyApp.Posts now has the following functions:

• list_posts
• get_post
• get_post!
• get_post_by
• get_post_by!
• fetch_post
• fetch_post_by
• create_post
• create_post!
• update_post
• update_post!
• delete_post
• delete_post!

Need to choose which functions are generated?

That seems reasonable. If you only wanted to define get_post, you can provide the :only option.

defmodule MyApp.Posts do
  use Contextual,
    name: {:post, :posts},
    schema: MyApp.Posts.Post,
    repo: MyApp.Repo,
    only: [:get]
end

Similarly, Contextual provides an :except option, which is basically just the opposite of :only.

Don't like the default function names?

Okay, that's fine. You can create your own name generator to solve this problem.

First, create a module that will serve as a name generator:

defmodule MyApp.ContextNaming do
  def generate_name(:list, {_singular, plural}) do
    :"all_#{plural}"
  end

  def generate_name(:get, {singular, _plural}) do
    :"find_#{singular}"
  end

  def generate_name(_, _), do: :default
end

Next, you'll need to configure your context to use your name generator:

defmodule MyApp.Posts do
  use Contextual,
    name: {:post, :posts},
    schema: MyApp.Posts.Post,
    repo: MyApp.Repo,
    name_generator: {MyApp.ContextNaming, :generate_name}
end

Now, you'll have all_posts instead of list_posts and find_post instead of get_post.

Contributing

The tests run against PostgreSQL. The test command will setup a test database for you.

To run the tests, just run:

$ mix test