StatesmanViz

A tool for visualizing state machines defined using Statesman

Installation

Add this line to your application's Gemfile:

gem 'statesman_viz'

And then execute:

$ bundle

Or install it yourself as:

$ gem install statesman_viz

Usage

• Define a Statesman state machine like below.

class OrderStateMachine
  include Statesman::Machine

  state :pending, initial: true
  state :checking_out
  state :purchased
  state :shipped
  state :cancelled
  state :failed
  state :refunded

  transition from: :pending,      to: [:checking_out, :cancelled]
  transition from: :checking_out, to: [:purchased, :cancelled]
  transition from: :purchased,    to: [:shipped, :failed]
  transition from: :shipped,      to: :refunded

  guard_transition(to: :checking_out) do |order|
    order.products_in_stock?
  end

  before_transition(from: :checking_out, to: :cancelled) do |order, transition|
    order.reallocate_stock
  end

  before_transition(to: :purchased) do |order, transition|
    PaymentService.new(order).submit
  end

  after_transition(to: :purchased) do |order, transition|
    MailerService.order_confirmation(order).deliver
  end
end

• Invoke StatesmanViz to generate the state machine diagram.

StatesmanViz.generate(OrderStateMachine)

• The output diagram is saved as OrderStateMachine.png in the current working directory.

Development

TODO

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/sannim1/statesmanviz. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the StatesmanViz project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.

Credit

Thanks to Tadas Sasnauskas and the lovely people at Ruby Hacknight - London ❤️