module ActiveModel module StateMachine class InvalidTransition < Exception end def self.included(base) require 'active_model/state_machine/machine' base.extend ClassMethods end module ClassMethods def inherited(klass) super klass.state_machines = state_machines end def state_machines @state_machines ||= {} end def state_machines=(value) @state_machines = value ? value.dup : nil end def state_machine(name = nil, options = {}, &block) if name.is_a?(Hash) options = name name = nil end name ||= :default state_machines[name] ||= Machine.new(self, name) block ? state_machines[name].update(options, &block) : state_machines[name] end def define_state_query_method(state_name) name = "#{state_name}?" undef_method(name) if method_defined?(name) class_eval "def #{name}; current_state.to_s == %(#{state_name}) end" end end def current_state(name = nil, new_state = nil, persist = false) sm = self.class.state_machine(name) ivar = sm.current_state_variable if name && new_state if persist && respond_to?(:write_state) write_state(sm, new_state) end if respond_to?(:write_state_without_persistence) write_state_without_persistence(sm, new_state) end instance_variable_set(ivar, new_state) else instance_variable_set(ivar, nil) unless instance_variable_defined?(ivar) value = instance_variable_get(ivar) return value if value if respond_to?(:read_state) value = instance_variable_set(ivar, read_state(sm)) end value || sm.initial_state end end end end