https://github.com/cheerfulstoic/ecto_require_associations

https://github.com/cheerfulstoic/ecto_require_associations

Last synced: 3 days ago
JSON representation

• Host: GitHub
• URL: https://github.com/cheerfulstoic/ecto_require_associations
• Owner: cheerfulstoic
• Created: 2023-05-11T13:14:11.000Z (over 1 year ago)
• Default Branch: main
• Last Pushed: 2023-10-30T15:29:14.000Z (about 1 year ago)
• Last Synced: 2024-03-15T05:05:48.277Z (8 months ago)
• Language: Elixir
• Size: 13.7 KB
• Stars: 6
• Watchers: 3
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

README

        
# EctoRequireAssociations

If you want to write purely functional functions based on Ecto data, you need to separate out your `Repo.preload`s.  This library helps you insert clean exceptions into those functions to make it clear when you have association dependencies.  See [this blog post](https://www.erlang-solutions.com/blog/lifting-your-loads-for-maintainable-elixir-applications/) for a more details discussion.

## Usage

A `EctoRequireAssociations.ensure!/2` function is defined which takes an ecto struct record and a specification of associations.  The specification works the same as the [`Ecto.Repo.preload/3`](https://hexdocs.pm/ecto/Ecto.Repo.html#c:preload/3) callback.

```elixir

def self_edited_posts(person) do

  EctoRequireAssociations.ensure!(person, [:settings, authored_posts: :editor])

  

  # Code which uses person.settings, person.authored_posts, and the

  # `editor` association on the authored posts

end

```

If any of the specified associations aren't loaded an `ArgumentError` will be raised

with a message like:

```

Expected association to be set: `authored_posts`

```

or if a nested preload is missing:

```

Expected association to be set: `authored_posts.editor`

```

If two associations are missing preloads:

```

Expected associations to be set: `settings`, `authored_posts.editor`

```

Ecto's `Ecto.assoc_loaded?/1` is used, so `nil` is considered a loaded value.

If an association isn't defined in the schema, a readable exception is produced instead:

```

Association `authored_psts` is not defined for the `MyApp.People.Person` struct

```

## Installation

If [available in Hex](https://hex.pm/docs/publish), the package can be installed

by adding `ecto_require_associations` to your list of dependencies in `mix.exs`:

```elixir

def deps do

  [

    {:ecto_require_associations, "~> 0.1.3"}

  ]

end

```

Documentation can be generated with [ExDoc](https://github.com/elixir-lang/ex_doc)

and published on [HexDocs](https://hexdocs.pm). Once published, the docs can

be found at .