https://github.com/feymartynov/ex_operation
A library for making domain operations in Elixir
https://github.com/feymartynov/ex_operation
business-logic ecto elixir railway-oriented-programming transaction
Last synced: 4 months ago
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A library for making domain operations in Elixir
- Host: GitHub
- URL: https://github.com/feymartynov/ex_operation
- Owner: feymartynov
- License: other
- Created: 2018-07-02T00:47:57.000Z (almost 8 years ago)
- Default Branch: master
- Last Pushed: 2019-06-22T02:20:26.000Z (almost 7 years ago)
- Last Synced: 2026-02-14T18:44:37.993Z (4 months ago)
- Topics: business-logic, ecto, elixir, railway-oriented-programming, transaction
- Language: Elixir
- Size: 45.9 KB
- Stars: 35
- Watchers: 1
- Forks: 5
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# ExOperation
[](https://travis-ci.org/feymartynov/ex_operation)
A library for making domain operations wrapped in a single database transaction.
## Resources
* [Documentation](https://hexdocs.pm/ex_operation)
* [Hex package](https://hex.pm/packages/ex_operation)
* [ExOperation: organizing business logic with operations in Elixir](https://medium.com/@feymartynov/exoperation-organizing-business-logic-with-operations-in-elixir-ce28a5f8b5ef)
* [Talk about ExOperation at Elixir-Lang Moscow meetup](https://youtu.be/ZIib_TV1tmo?t=2360) (in Russian)
* [Example Phoenix app](https://github.com/feymartynov/ex_operation_phoenix_example)
## Example
An operation definition:
```elixir
defmodule MyApp.Book.Update do
use ExOperation, params: %{
id!: :integer,
title!: :string,
author_id: :integer
}
def validate_params(changeset) do
changeset
|> Ecto.Changeset.validate_length(:title, min: 5)
end
def call(operation) do
operation
|> find(:book, schema: MyApp.Book, preload: [:author])
|> find(:author, schema: MyApp.Author, id_path: [:author_id], optional: true)
|> step(:result, &do_update(operation.context, &1, operation.params))
|> after_commit(&send_notifcation(&1))
end
defp do_update(context, txn, params) do
txn.book
|> Ecto.Changeset.cast(params, [:title])
|> Ecto.Changeset.put_assoc(:author, txn.author)
|> Ecto.Changeset.put_assoc(:updated_by, context.current_user)
|> MyApp.Repo.update()
end
defp send_notification(txn) do
# …
{:ok, txn}
end
end
```
The call:
```elixir
context = %{current_user: current_user}
with {:ok, %{result: book}} <- MyApp.Book.Update |> ExOperation.run(context, params) do
# …
end
```
### Usage with Phoenix
An example Phoenix app can be found here: [ex_operation_phoenix_example](https://github.com/feymartynov/ex_operation_phoenix_example).
## Features
* [Railway oriented](https://fsharpforfunandprofit.com/rop/) domain logic pipeline.
* Running all steps in a single database transaction. It uses [Ecto.Multi](https://hexdocs.pm/ecto/Ecto.Multi.html) inside.
* Params casting & validation with `Ecto.Changeset`. Thanks to [params](https://github.com/vic/params) library.
* Convenient fetching of entitites from the database.
* Context passing. Useful for passing current user, current locale etc.
* Composable operations: one operation can call another through `suboperation/3` function.
* Changing operation scenario based on previous steps results with `defer/2`.
* Hooks: `before_transaction/1`, `after_commit/1`.
## Installation
Add the following to your `mix.exs` and then run `mix deps.get`:
```elixir
def deps do
[
{:ex_operation, "~> 0.5.0"}
]
end
```
Add to your `config/config.exs`:
```elixir
config :ex_operation,
repo: MyApp.Repo
```
where `MyApp.Repo` is the name of your Ecto.Repo module.