# State Machine for Ecto
State machine pattern in Ecto.
Example:
```
defmodule Example.User do
use Example.Web, :model
import StateMc.EctoSm
schema "users" do
field :state, :string, default: "waiting"
end
statemc :state do
defstate [:waiting, :approved, :rejected]
defevent :approve, %{from: [:waiting, :rejected], to: :approved}, fn(changeset) ->
changeset
|> Example.Repo.update()
end
defevent :reject, %{from: [:waiting, :approved], to: :rejected}, fn(changeset) ->
changeset
|> Example.Repo.update()
end
end
end
```
## How to run?
```
user = Example.Repo.get(Example.User, 1)
Example.User.current_state(user) # => get current state
Example.User.can_approve?(user) # => check event approve
Example.User.can_reject?(user) # => check event reject
Example.User.approve(user) # => call event approve to change state to approved
Example.User.reject(user) # => call event reject to change state to rejected
```
## Installation
If [available in Hex](https://hex.pm/docs/publish), the package can be installed as:
1. Add `state_mc` to your list of dependencies in `mix.exs`:
```elixir
def deps do
[{:state_mc, "~> 0.1.0"}]
end
```
2. Ensure `state_mc` is started before your application:
```elixir
def application do
[applications: [:state_mc]]
end
```