https://github.com/system76/state_fair

State machine system for Elixir applications
https://github.com/system76/state_fair

Last synced: about 2 months ago
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State machine system for Elixir applications

• Host: GitHub
• URL: https://github.com/system76/state_fair
• Owner: system76
• License: mit
• Created: 2015-10-27T22:06:45.000Z (about 9 years ago)
• Default Branch: master
• Last Pushed: 2015-10-27T22:07:32.000Z (about 9 years ago)
• Last Synced: 2023-08-03T10:10:11.290Z (over 1 year ago)
• Language: Elixir
• Size: 109 KB
• Stars: 3
• Watchers: 4
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.md

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README

        
# StateFair

Inspired by the[`state_machine` ruby gem](https://github.com/pluginaweek/state_machine),

this

## Installation

The package can be installed as:

  1. Add state_fair to your list of dependencies in `mix.exs`:

        def deps do

          [{:state_fair, "~> 0.1"}]

        end

## Overview

```elixir

defmodule Order do

  import StateFair

  defstruct status: :new

  state_manager :status do

    event :purchase do

      transition from: :new, to: :ordered

    end

    event :ship do

      transition from: :ordered, to: :shipped

    end

    event :cancel do

      transition from: [:new, :ordered], to: :cancelled

    end

    event :force_cancel do

      transition from: {:any}, to: :cancelled

    end

  end

end

order = %Order{status: :new}

{:ok, order} = order |> Order.purchase # => order.status == :ordered

if order |> Order.can_ship? do

  order = order |> Order.ship! # => order.status == :shipped

end

order |> Order.cancel # => :error

order |> Order.cancel! # throws StateFair.InvalidTransitionError

order |> Order.force_cancel! # => order.status == :cancelled

```