Class: FSM::Machine

Inherits:
Object
  • Object
show all
Defined in:
lib/fsm/machine.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(target_class) ⇒ Machine

Returns a new instance of Machine.



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# File 'lib/fsm/machine.rb', line 5

def initialize(target_class)
  @target_class = target_class
  self.states = []
  self.transitions = []
  self.current_state_attribute_name = :state
end

Instance Attribute Details

#current_state_attribute_name ⇒ Object

Returns the value of attribute current_state_attribute_name.



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# File 'lib/fsm/machine.rb', line 3

def current_state_attribute_name
  @current_state_attribute_name
end

#initial_state_name ⇒ Object

Returns the value of attribute initial_state_name.



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# File 'lib/fsm/machine.rb', line 3

def initial_state_name
  @initial_state_name
end

#states ⇒ Object

Returns the value of attribute states.



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# File 'lib/fsm/machine.rb', line 3

def states
  @states
end

#transitions ⇒ Object

Returns the value of attribute transitions.



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# File 'lib/fsm/machine.rb', line 3

def transitions
  @transitions
end

Class Method Details

.[](includer) ⇒ Object 



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# File 'lib/fsm/machine.rb', line 12

def self.[](includer)
  (@machines ||= {})[includer]
end

.[]=(*args) ⇒ Object 



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# File 'lib/fsm/machine.rb', line 16

def self.[]=(*args)
  (@machines ||= {})[args.first] = args.last
end

.get_current_state_name(target) ⇒ Object 



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# File 'lib/fsm/machine.rb', line 41

def self.get_current_state_name(target)
  target.send(Machine[target.class].current_state_attribute_name) || self.initial_state_name
end

.set_current_state_name(target, value) ⇒ Object 



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# File 'lib/fsm/machine.rb', line 45

def self.set_current_state_name(target, value)
  value = value && value.is_a?(Symbol) ? value.to_s : value
  target.send("#{Machine[target.class].current_state_attribute_name}=", value)
end

Instance Method Details

#available_transitions(target) ⇒ Object 



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# File 'lib/fsm/machine.rb', line 60

def available_transitions(target)
  current_state_name = Machine.get_current_state_name(target)
  state = state_for_name(current_state_name)
  state.transitions.values
end

#build_transition_methods ⇒ Object 



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# File 'lib/fsm/machine.rb', line 67

def build_transition_methods
  names = self.transitions.map() {|transition| transition.name}.uniq
  names.each do |name|
    define_transition_method(name)
  end
end

#draw_graph(options = {}) ⇒ Object 



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# File 'lib/fsm/machine.rb', line 94

def draw_graph(options = {})
  format = options[:format] || :png
  extension = options[:extension] || format
  file_name = options[:outfile] || "#{@target_class.name.downcase}.#{extension}" 
  cmd = "dot -T#{format} -o#{file_name}"
  IO.popen cmd, 'w' do |io| 
    io.write to_dot
  end 
  raise 'dot failed' unless $?.success? 
end

#reachable_states(target) ⇒ Object 



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# File 'lib/fsm/machine.rb', line 51

def reachable_states(target)
  reachables = []
  current_state_name = Machine.get_current_state_name(target)
  self.states.map do |state|
    reachables += state.to_states if state.name == current_state_name
  end
  reachables
end

#state(name, options = {}) ⇒ Object 



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# File 'lib/fsm/machine.rb', line 20

def state(name, options = {})
  raise "State is already defined: '#{name}'" if self.state_for_name(name, true)
  self.states << State.new(name, @target_class, options)
  self.initial_state_name=(name) unless self.initial_state_name
end

#state_for_name(name, quiet = false) ⇒ Object

Lookup a State by it’s name raises ArgumentError if state can not be found unless quiet is set to true

Raises:

  • (ArgumentError) 


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# File 'lib/fsm/machine.rb', line 76

def state_for_name(name, quiet = false)
  state = self.states.detect() {|state| state.name == name}
  raise ArgumentError.new("Unknonw state '#{name}'") unless quiet || state
  state
end

#to_dot(options = {}) ⇒ Object

Convert this state machine to the dot format of graphviz



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# File 'lib/fsm/machine.rb', line 83

def to_dot(options = {})
  s = self.states.map do |state|
    "  #{state.to_dot(options)};"
  end
  t = self.transitions.map do |transition|
    "  #{transition.to_dot(options)};"
  end
  "digraph FSM_#{@target_class.name} {\n#{s.join("\n")}\n\n#{t.join("\n")}\n}"
end

#transition(name, from_name, to_name, options = {}) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/fsm/machine.rb', line 31

def transition(name, from_name, to_name, options = {})
  raise ArgumentError.new("name, from_name and to_name are required") if name.nil? || from_name.nil? || to_name.nil?
  
  from_state = self.state_for_name(from_name)
  to_state = self.state_for_name(to_name)
  transition = Transition.new(name, from_state, to_state, options)
  from_state.add_transition(transition)
  self.transitions << transition
end