Class: Polytrix::Challenge::FSM Private

Inherits:

Object

• Object
• Polytrix::Challenge::FSM

Defined in:

lib/polytrix/challenge.rb

Overview

This class is part of a private API. You should avoid using this class if possible, as it may be removed or be changed in the future.

The simplest finite state machine pseudo-implementation needed to manage an Instance.

Constant Summary

TRANSITIONS =

This constant is part of a private API. You should avoid using this constant if possible, as it may be removed or be changed in the future.

[:destroy, :detect, :exec, :verify]

Class Method Summary

• .actions(last = nil, desired) ⇒ Array<Symbol> private

  Returns an Array of all transitions to bring an Instance from its last reported transistioned state into the desired transitioned state.

• .index(transition) ⇒ Object private

  Determines the index of a state in the state lifecycle vector.

Class Method Details

.actions(last = nil, desired) ⇒ Array<Symbol>

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns an Array of all transitions to bring an Instance from its last reported transistioned state into the desired transitioned state.

Parameters:

• last (String, Symbol, nil) (defaults to: nil) —

  the last known transitioned state of the Instance, defaulting to ‘nil` (for unknown or no history)

• desired (String, Symbol) —

  the desired transitioned state for the Instance

Returns:

• (Array<Symbol>) —

  an Array of transition actions to perform

# File 'lib/polytrix/challenge.rb', line 297

def self.actions(last = nil, desired)
  last_index = index(last)
  desired_index = index(desired)

  if last_index == desired_index || last_index > desired_index
    Array(TRANSITIONS[desired_index])
  else
    TRANSITIONS.slice(last_index + 1, desired_index - last_index)
  end
end

.index(transition) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Determines the index of a state in the state lifecycle vector. Woah.

Parameters:

• transition (Symbol, #to_sym) —

  a state

• the (Integer) —

  index position

# File 'lib/polytrix/challenge.rb', line 315

def self.index(transition)
  if transition.nil?
    0
  else
    TRANSITIONS.find_index { |t| t == transition.to_sym }
  end
end