Class: SimpleStateMachine::StateMachine

Inherits:
Object
  • Object
show all
Defined in:
lib/simple_state_machine/simple_state_machine.rb

Overview

Defines the state machine used by the instance

Instance Method Summary collapse

Constructor Details

#initialize(subject) ⇒ StateMachine

Returns a new instance of StateMachine.



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# File 'lib/simple_state_machine/simple_state_machine.rb', line 102

def initialize(subject)
  @subject = subject
end

Instance Method Details

#error_state(event_name, error) ⇒ Object

Returns the error state for the subject for event_name and error



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# File 'lib/simple_state_machine/simple_state_machine.rb', line 113

def error_state(event_name, error)
  transition = transitions.select{|t| t.is_error_transition_for?(event_name, error) }.first
  transition ? transition.to : nil
end

#next_state(event_name) ⇒ Object

Returns the next state for the subject for event_name



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# File 'lib/simple_state_machine/simple_state_machine.rb', line 107

def next_state(event_name)
  transition = transitions.select{|t| t.is_transition_for?(event_name, @subject.send(state_method))}.first
  transition ? transition.to : nil
end

#transition(event_name) ⇒ Object

Transitions to the next state if next_state exists. Calls illegal_event_callback event_name if no next_state is found



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# File 'lib/simple_state_machine/simple_state_machine.rb', line 120

def transition(event_name)
  if to = next_state(event_name)
    begin
      result = yield
    rescue => e
      if error_state = error_state(event_name, e)
        @subject.send("#{state_method}=", error_state)
        return result
      else
        raise
      end
    end
    # TODO refactor out to AR module
    if defined?(::ActiveRecord) && @subject.is_a?(::ActiveRecord::Base)
      if @subject.errors.entries.empty?
        @subject.send("#{state_method}=", to)
        return true
      else
        return false
      end
    else
      @subject.send("#{state_method}=", to)
      return result
    end
  else
    illegal_event_callback event_name
  end
end