Module: StatePattern

Defined in:
lib/state_pattern.rb,
lib/state_pattern/state.rb,
lib/state_pattern/invalid_transition_exception.rb

Defined Under Namespace

Modules: ClassMethods Classes: InvalidTransitionException, State

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.included(base) ⇒ Object 



5
6
7
 
# File 'lib/state_pattern.rb', line 5

def self.included(base)
  base.extend ClassMethods
end

Instance Method Details

#current_state_instance ⇒ Object 



83
84
85
86
 
# File 'lib/state_pattern.rb', line 83

def current_state_instance
  set_state if @current_state_instance.nil?
  @current_state_instance
end

#delegate_to_state(state_method_name, *args, &block) ⇒ Object 



88
89
90
91
 
# File 'lib/state_pattern.rb', line 88

def delegate_to_state(state_method_name, *args, &block)
  @current_method = state_method_name.to_sym
  self.current_state_instance.send(@current_method, *args, &block)
end

#raise_invalid_transition_to(state_class) ⇒ Object

Raises:



99
100
101
 
# File 'lib/state_pattern.rb', line 99

def raise_invalid_transition_to(state_class)
  raise InvalidTransitionException.new(current_state_instance.class, state_class, @current_method)
end

#set_state(state_class = nil) ⇒ Object 



77
78
79
80
81
 
# File 'lib/state_pattern.rb', line 77

def set_state(state_class = nil)
  state_class ||= self.class.initial_state_class
  return @current_state_instance if @current_state_instance.class == state_class
  @current_state_instance = state_class.new(self, @current_state_instance)
end

#transition_to(next_state_class) ⇒ Object 



93
94
95
96
97
 
# File 'lib/state_pattern.rb', line 93

def transition_to(next_state_class)
  raise_invalid_transition_to(next_state_class) unless valid_transition?(current_state_instance.class, next_state_class)
  current_state_instance.exit
  set_state(next_state_class)
end

#valid_transition?(from_state, to_state) ⇒ Boolean

Returns:

  • (Boolean) 


103
104
105
106
107
108
109
 
# File 'lib/state_pattern.rb', line 103

def valid_transition?(from_state, to_state)
  transitions = self.class.transitions_hash
  return true if transitions.nil?

  valid_transition_targets = transitions[from_state] || transitions[[from_state, @current_method]]
  valid_transition_targets && valid_transition_targets.include?(to_state)
end