Contents

module StateMachina
  class Transition
    attr_reader :model_name, :machine_name, :event_name, :from_state_name, :to_state_name, :guard, :metadata
    attr_accessor :machine, :guard_context
    alias_method :state_machine, :machine

    def initialize(model_name, machine_name, event_name, from_state_name, to_state_name, guard: nil, metadata: {})
      @model_name = model_name
      @machine_name = machine_name
      @event_name = event_name
      @from_state_name = from_state_name.to_s
      @to_state_name = to_state_name.to_s
      @guard = guard
      @metadata = metadata
    end

    def possible?
      return false if machine.nil?

      from_state_name == machine.current_state_name
    end

    def permitted?
      return true if guard.nil?
      return false if guard_context.nil?

      case guard
      when Symbol
        guard_context.public_send(guard) # Supports `guard: :meat?`
      when Proc
        if guard.arity >= 1
          guard.call(guard_context) # Supports `guard: (model) -> { model.meat? }`
        else
          guard_context.instance_exec(&guard) # Supports `guard: -> { meat? }`
        end
      else
        guard.call(guard_context) if guard.respond_to?(:call) # Supports `guard: CallableObject`
      end
    end

    def execute
      return false if machine.nil?

      machine.update_state(to_state_name)
    end
  end
end

Version data entries

3 entries across 3 versions & 1 rubygems

Version	Path
state_machina-0.1.2	lib/state_machina/transition.rb
state_machina-0.1.1	lib/state_machina/transition.rb
state_machina-0.1.0	lib/state_machina/transition.rb