Class StateMachine::NodeCollection
In: lib/state_machine/node_collection.rb
Parent: Object

Represents a collection of nodes in a state machine, be it events or states.

Methods

<<   []   at   concat   each   fetch   keys   length   machine=   new   update  

Included Modules

Enumerable Assertions

Attributes

machine  [R]  The machine associated with the nodes

Public Class methods

Creates a new collection of nodes for the given state machine. By default, the collection is empty.

Configuration options:

  • :index - One or more attributes to automatically generate hashed indices for in order to perform quick lookups. Default is to index by the :name attribute

[Source]

    # File lib/state_machine/node_collection.rb, line 19
19:     def initialize(machine, options = {})
20:       assert_valid_keys(options, :index)
21:       options = {:index => :name}.merge(options)
22:       
23:       @machine = machine
24:       @nodes = []
25:       @indices = Array(options[:index]).inject({}) {|indices, attribute| indices[attribute] = {}; indices}
26:       @default_index = Array(options[:index]).first
27:     end

Public Instance methods

Adds a new node to the collection. By doing so, this will also add it to the configured indices.

[Source]

    # File lib/state_machine/node_collection.rb, line 59
59:     def <<(node)
60:       @nodes << node
61:       @indices.each {|attribute, index| index[value(node, attribute)] = node}
62:       self
63:     end

Gets the node indexed by the given key. By default, this will look up the key in the first index configured for the collection. A custom index can be specified like so:

  collection['parked', :value]

The above will look up the "parked" key in a hash indexed by each node‘s value attribute.

If the key cannot be found, then nil will be returned.

[Source]

     # File lib/state_machine/node_collection.rb, line 124
124:     def [](key, index_name = @default_index)
125:       index(index_name)[key]
126:     end

Gets the node at the given index.

  states = StateMachine::NodeCollection.new
  states << StateMachine::State.new(machine, :parked)
  states << StateMachine::State.new(machine, :idling)

  states.at(0).name    # => :parked
  states.at(1).name    # => :idling

[Source]

     # File lib/state_machine/node_collection.rb, line 110
110:     def at(index)
111:       @nodes[index]
112:     end

Appends a group of nodes to the collection

[Source]

    # File lib/state_machine/node_collection.rb, line 66
66:     def concat(nodes)
67:       nodes.each {|node| self << node}
68:     end

Calls the block once for each element in self, passing that element as a parameter.

  states = StateMachine::NodeCollection.new
  states << StateMachine::State.new(machine, :parked)
  states << StateMachine::State.new(machine, :idling)
  states.each {|state| puts state.name, ' -- '}

…produces:

  parked -- idling --

[Source]

     # File lib/state_machine/node_collection.rb, line 97
 97:     def each
 98:       @nodes.each {|node| yield node}
 99:       self
100:     end

Gets the node indexed by the given key. By default, this will look up the key in the first index configured for the collection. A custom index can be specified like so:

  collection['parked', :value]

The above will look up the "parked" key in a hash indexed by each node‘s value attribute.

If the key cannot be found, then an IndexError exception will be raised:

  collection['invalid', :value]   # => IndexError: "invalid" is an invalid value

[Source]

     # File lib/state_machine/node_collection.rb, line 140
140:     def fetch(key, index_name = @default_index)
141:       self[key, index_name] || raise(IndexError, "#{key.inspect} is an invalid #{index_name}")
142:     end

Gets the set of unique keys for the given index

[Source]

    # File lib/state_machine/node_collection.rb, line 53
53:     def keys(index_name = @default_index)
54:       index(index_name).keys
55:     end

Gets the number of nodes in this collection

[Source]

    # File lib/state_machine/node_collection.rb, line 48
48:     def length
49:       @nodes.length
50:     end

Changes the current machine associated with the collection. In turn, this will change the state machine associated with each node in the collection.

[Source]

    # File lib/state_machine/node_collection.rb, line 42
42:     def machine=(new_machine)
43:       @machine = new_machine
44:       each {|node| node.machine = new_machine}
45:     end

Updates the indexed keys for the given node. If the node‘s attribute has changed since it was added to the collection, the old indexed keys will be replaced with the updated ones.

[Source]

    # File lib/state_machine/node_collection.rb, line 73
73:     def update(node)
74:       @indices.each do |attribute, index|
75:         old_key = RUBY_VERSION < '1.9' ? index.index(node) : index.key(node)
76:         new_key = value(node, attribute)
77:         
78:         # Only replace the key if it's changed
79:         if old_key != new_key
80:           index.delete(old_key)
81:           index[new_key] = node
82:         end
83:       end
84:     end

[Validate]