Module: Rave::Mixins::ObjectFactory

Included in:
Rave::Models::Annotation, Rave::Models::Element, Rave::Models::Event
Defined in:
lib/mixins/object_factory.rb

Overview

Abstract object that allows you to create instances of the classes inside it based on providing a type name.

Constant Summary collapse

WILDCARD = 
'*'

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Attribute Details

#type ⇒ Object (readonly)

:nodoc:



81
82
83
 
# File 'lib/mixins/object_factory.rb', line 81

def type
  @type
end

Class Method Details

.included(base) ⇒ Object 



8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
 
# File 'lib/mixins/object_factory.rb', line 8

def self.included(base)
  base.class_eval do
    # Store the registered classes in a class instance variable.
    class << self
      attr_reader :class_by_type_mapping
      attr_reader :class_by_pattern_mapping
    end

    @class_by_type_mapping = {}
    @class_by_pattern_mapping = {}

    class_eval(<<-END, __FILE__, __LINE__)
      def self.classes_by_type
        ::#{self.name}.class_by_type_mapping
      end
      def self.classes_by_pattern
        ::#{self.name}.class_by_pattern_mapping
      end
    END

    # Object factory method.
    #
    # :type - Type of object to create [String]
    def self.create(type, *args, &block)
      if classes_by_type.has_key? type
        return classes_by_type[type].new(*args, &block)
      elsif
        # Check for pattern-based types. Check for longer matches before shorter ones.
        patterns = classes_by_pattern.keys.sort { |a, b| b.to_s.length <=> a.to_s.length }
        patterns.each do |pattern|
          if type =~ pattern
            return classes_by_pattern[pattern].new($1, *args, &block)
          end
        end
        raise ArgumentError.new("Unknown #{self} type #{type}")
      end
    end

    # Is this type able to be created?
    def self.valid_type?(type)
      classes_by_type.has_key? type
    end

    # Register this class with its factory.
    def self.factory_register(type)
      classes_by_type[type] = self

      # * in a type indicates a wildcard.
      if type[WILDCARD]
        classes_by_pattern[/^#{type.sub(WILDCARD, '(.*)')}$/] = self
      end
      
      class << self
        def type; @type.dup; end
      end

      @type = type

    end

    # Classes that can be generated by the factory [Array of Class]
    def self.classes
      classes_by_type.values
    end

    # Types that can be generated by the factory [Array of String]
    def self.types
      classes_by_type.keys
    end
  end
end