class StateMachine::PathCollection

Represents a collection of paths that are generated based on a set of requirements regarding what states to start and end on

Attributes

from_name[R]

The initial state to start each path from

machine[R]

The state machine these path are walking

object[R]

The object whose state machine is being walked

to_name[R]

The target state for each path

Public Class Methods

new(object, machine, options = {}) click to toggle source

Creates a new collection of paths with the given requirements.

Configuration options:

  • :from - The initial state to start from

  • :to - The target end state

  • :deep - Whether to enable deep searches for the target state.

  • :guard - Whether to guard transitions with the if/unless conditionals defined for each one

# File lib/state_machine/path_collection.rb, line 29
def initialize(object, machine, options = {})
  options = {:deep => false, :from => machine.states.match!(object).name}.merge(options)
  assert_valid_keys(options, :from, :to, :deep, :guard)
  
  @object = object
  @machine = machine
  @from_name = machine.states.fetch(options[:from]).name
  @to_name = options[:to] && machine.states.fetch(options[:to]).name
  @guard = options[:guard]
  @deep = options[:deep]
  
  initial_paths.each {|path| walk(path)}
end

Public Instance Methods

events() click to toggle source

Lists all of the events that can be fired through the paths in this collection.

For example,

paths.events  # => [:park, :ignite, :shift_up, ...]
# File lib/state_machine/path_collection.rb, line 69
def events
  map {|path| path.events}.flatten.uniq
end
from_states() click to toggle source

Lists all of the states that can be transitioned from through the paths in this collection.

For example,

paths.from_states # => [:parked, :idling, :first_gear, ...]
# File lib/state_machine/path_collection.rb, line 49
def from_states
  map {|path| path.from_states}.flatten.uniq
end
to_states() click to toggle source

Lists all of the states that can be transitioned to through the paths in this collection.

For example,

paths.to_states # => [:idling, :first_gear, :second_gear, ...]
# File lib/state_machine/path_collection.rb, line 59
def to_states
  map {|path| path.to_states}.flatten.uniq
end

Private Instance Methods

initial_paths() click to toggle source

Gets the initial set of paths to walk

# File lib/state_machine/path_collection.rb, line 75
def initial_paths
  machine.events.transitions_for(object, :from => from_name, :guard => @guard).map do |transition|
    path = Path.new(object, machine, :target => to_name, :guard => @guard)
    path << transition
    path
  end
end
walk(path) click to toggle source

Walks down the given path. Each new path that matches the configured requirements will be added to this collection.

# File lib/state_machine/path_collection.rb, line 85
def walk(path)
  self << path if path.complete?
  path.walk {|next_path| walk(next_path)} unless to_name && path.complete? && !@deep
end