ruby - peter-murach/finite_machine restore persisted state -

using finite machine gem ruby piotr murach.

would restore state machine persisted (stored) state. documentation teaches initial state, , restoring state , activerecord model.

all i've been able find dsl lets me define initial state, or define event transitions initial state. both require me define initial state @ coding time.

fm = finitemachine.define   initial :red 

or

fm = finitemachine.define   events {     event :start, :none   => :red 

in practice, i'm defining "standalone" along lines of,

class engine < finitemachine::definition   initial :neutral 

what i'd define initial state in initializer class, like:

class engine < finitemachine::definition      def initialize(car, state)        initial state        target car      end 

however not work. :none current state after initialization.

found restore! method , section in doc persisting state activerecord. tried along lines of:

class engine < finitemachine::definition      def initialize(car, state)        restore! state        target car      end 

however constructor returns class finitemachine::statemachine when called new on it. new method takes number of arguments, , initialize method of class never called. returns different class.

here output program follows:

gsm class finitemachine::statemachine gsm current state red .gems/gems/finite_machine-0.10.1/lib/finite_machine/state_machine.rb:259:in `valid_state?': inappropriate current state 'red' (finitemachine::invalidstateerror) 

the program:

require 'finite_machine'  class genericstatemachine < finitemachine::definition   initial :red    def initialize(light)     puts "initializer #{light}"     super     restore! light.state     target light   end    events {     event :start, :red => :green     event :stop, :green => :red   }    callbacks {     on_enter { |event| target.state = event.to }   } end  class light   attr_accessor :state   def initialize     state = 'green'   end   def to_s     "light in state #{state}"   end end  light = light.new gsm = genericstatemachine.new(light) puts "gsm class #{gsm.class.to_s}" puts "gsm current state #{gsm.current}" gsm.stop puts "gsm state after stop #{gsm.current}" puts "light state after stop #{light.state}" 

what works better make state machine factory method, uses dsl via finitemachine.define

here output program follows:

creating machine light in state green gsm class finitemachine::statemachine gsm current state green gsm state after stop red light state after stop red 

the program:

require 'finite_machine'  class lightmachinefactory   def self.create_machine(light)     finitemachine.define       puts "creating machine #{light}"       initial light.state       target light        events {         event :start, :red => :green         event :stop, :green => :red       }        callbacks {         on_enter { |event| target.state = event.to }       }     end   end end  class light   attr_accessor :state   def initialize     @state = 'green'   end   def to_s     "light in state #{state}"   end   def state     @state.to_sym   end end  light = light.new gsm = lightmachinefactory.create_machine(light) puts "gsm class #{gsm.class.to_s}" puts "gsm current state #{gsm.current}" gsm.stop puts "gsm state after stop #{gsm.current}" puts "light state after stop #{light.state}" 

this content shared (my) closed issue in github source repository gem. (this better forum more usage question issue.)