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Diffstat (limited to 'activemodel/lib/active_model/state_machine.rb')
| -rw-r--r-- | activemodel/lib/active_model/state_machine.rb | 219 |
1 files changed, 0 insertions, 219 deletions
diff --git a/activemodel/lib/active_model/state_machine.rb b/activemodel/lib/active_model/state_machine.rb deleted file mode 100644 index 64b91c1659..0000000000 --- a/activemodel/lib/active_model/state_machine.rb +++ /dev/null @@ -1,219 +0,0 @@ -module ActiveModel - - # ActiveModel::StateMachine provides methods that turn your object into a - # finite state machine, able to move from one state to another. - # - # A minimal implementation could be: - # - # class EmailMessage - # include ActiveModel::StateMachine - # - # state_machine do - # state :unread - # state :read - # end - # - # event :open_email do - # transitions :to => :read, :from => :unread - # end - # end - # - # === Examples - # - # class TrafficLight - # include ActiveModel::StateMachine - # - # attr_reader :runners_caught - # - # def initialize - # @runners_caught = 0 - # end - # - # state_machine do - # state :red - # state :green - # state :yellow - # state :blink - # - # event :change_color do - # transitions :to => :red, :from => [:yellow], - # :on_transition => :catch_runners - # transitions :to => :green, :from => [:red] - # transitions :to => :yellow, :from => [:green] - # end - # - # event :defect do - # transitions :to => :blink, :from => [:yellow, :red, :green] - # end - # - # event :repair do - # transitions :to => :red, :from => [:blink] - # end - # end - # - # def catch_runners - # @runners_caught += 1 - # end - # end - # - # light = TrafficLight.new - # light.current_state # => :red - # light.change_color! # => true - # light.current_state # => :green - # light.green? # => true - # light.change_color! # => true - # light.current_state # => :yellow - # light.red? # => false - # light.change_color! # => true - # light.runners_caught # => 1 - # - # * The initial state for TrafficLight is red which is the first state defined. - # - # TrafficLight.state_machine.initial_state # => :red - # - # * Call an event to transition a state machine, e.g. <tt>change_color!</tt>. - # You can call the event with or without the exclamation mark, however, the common Ruby - # idiom is to name methods that directly change the state of the receivier with - # an exclamation mark, so <tt>change_color!</tt> is preferred over <tt>change_color</tt>. - # - # light.current_state #=> :green - # light.change_color! #=> true - # light.current_state #=> :yellow - # - # * On a succesful transition to red (from yellow), the local +catch_runners+ - # method is executed - # - # light.current_state #=> :red - # light.change_color! #=> true - # light.runners_caught #=> 1 - # - # * The object acts differently depending on its current state, for instance, - # the change_color! method has a different action depending on the current - # color of the light - # - # light.change_color! #=> true - # light.current_state #=> :red - # light.change_color! #=> true - # light.current_state #=> :green - # - # * Get the possible events for a state - # - # TrafficLight.state_machine.events_for(:red) # => [:change_color, :defect] - # TrafficLight.state_machine.events_for(:blink) # => [:repair] - # - # The StateMachine also supports the following features : - # - # * Success callbacks on event transition - # - # event :sample, :success => :we_win do - # ... - # end - # - # * Enter and exit callbacks par state - # - # state :open, :enter => [:alert_twitter, :send_emails], :exit => :alert_twitter - # - # * Guards on transition - # - # event :close do - # # You may only close the store if the safe is locked!! - # transitions :to => :closed, :from => :open, :guard => :safe_locked? - # end - # - # * Setting the initial state - # - # state_machine :initial => :yellow do - # ... - # end - # - # * Named the state machine, to have more than one - # - # class Stated - # include ActiveModel::StateMachine - # - # strate_machine :name => :ontest do - # end - # - # state_machine do - # end - # end - # - # # Get the state of the <tt>:ontest</tt> state machine - # stat.current_state(:ontest) - # # Get the initial state - # Stated.state_machine(:ontest).initial_state - # - # * Changing the state - # - # stat.current_state(:default, :astate) # => :astate - # # But you must give the name of the state machine, here <tt>:default</tt> - # - module StateMachine - autoload :Event, 'active_model/state_machine/event' - autoload :Machine, 'active_model/state_machine/machine' - autoload :State, 'active_model/state_machine/state' - autoload :StateTransition, 'active_model/state_machine/state_transition' - - extend ActiveSupport::Concern - - class InvalidTransition < Exception - 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 |