class StateMachine::StateCollection

Represents a collection of states in a state machine

Public Instance Methods

by_priority() click to toggle source

Gets the order in which states should be displayed based on where they were first referenced. This will order states in the following priority:

  1. Initial state

  2. Event transitions (:from, :except_from, :to, :except_to options)

  3. States with behaviors

  4. States referenced via state or other_states

  5. States referenced in callbacks

This order will determine how the GraphViz visualizations are rendered.

# File lib/state_machine/state_collection.rb, line 93
def by_priority
  order = select {|state| state.initial}.map {|state| state.name}
  
  machine.events.each {|event| order += event.known_states}
  order += select {|state| state.methods.any?}.map {|state| state.name}
  order += keys(:name) - machine.callbacks.values.flatten.map {|callback| callback.known_states}.flatten
  order += keys(:name)
  
  order.uniq!
  order.map! {|name| self[name]}
  order
end
match(object) click to toggle source

Determines the current state of the given object as configured by this state machine. This will attempt to find a known state that matches the value of the attribute on the object.

Examples

class Vehicle
  state_machine :initial => :parked do
    other_states :idling
  end
end

states = Vehicle.state_machine.states

vehicle = Vehicle.new         # => #<Vehicle:0xb7c464b0 @state="parked">
states.match(vehicle)         # => #<StateMachine::State name=:parked value="parked" initial=true>

vehicle.state = 'idling'
states.match(vehicle)         # => #<StateMachine::State name=:idling value="idling" initial=true>

vehicle.state = 'invalid'
states.match(vehicle)         # => nil
# File lib/state_machine/state_collection.rb, line 55
def match(object)
  value = machine.read(object, :state)
  self[value, :value] || detect {|state| state.matches?(value)}
end
match!(object) click to toggle source

Determines the current state of the given object as configured by this state machine. If no state is found, then an ArgumentError will be raised.

Examples

class Vehicle
  state_machine :initial => :parked do
    other_states :idling
  end
end

states = Vehicle.state_machine.states

vehicle = Vehicle.new         # => #<Vehicle:0xb7c464b0 @state="parked">
states.match!(vehicle)        # => #<StateMachine::State name=:parked value="parked" initial=true>

vehicle.state = 'invalid'
states.match!(vehicle)        # => ArgumentError: "invalid" is not a known state value
# File lib/state_machine/state_collection.rb, line 79
def match!(object)
  match(object) || raise(ArgumentError, "#{machine.read(object, :state).inspect} is not a known #{machine.name} value")
end
matches?(object, name) click to toggle source

Determines whether the given object is in a specific state. If the object's current value doesn't match the state, then this will return false, otherwise true. If the given state is unknown, then an IndexError will be raised.

Examples

class Vehicle
  state_machine :initial => :parked do
    other_states :idling
  end
end

states = Vehicle.state_machine.states
vehicle = Vehicle.new               # => #<Vehicle:0xb7c464b0 @state="parked">

states.matches?(vehicle, :parked)   # => true
states.matches?(vehicle, :idling)   # => false
states.matches?(vehicle, :invalid)  # => IndexError: :invalid is an invalid key for :name index
# File lib/state_machine/state_collection.rb, line 29
def matches?(object, name)
  fetch(name).matches?(machine.read(object, :state))
end

Private Instance Methods

value(node, attribute) click to toggle source

Gets the value for the given attribute on the node

Calls superclass method StateMachine::NodeCollection#value
# File lib/state_machine/state_collection.rb, line 108
def value(node, attribute)
  attribute == :value ? node.value(false) : super
end