1
2
3
4
5
6
7
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
|
# frozen_string_literal: true
module DDPlugin
# The registry is responsible for keeping track of all loaded plugins.
class Registry
# Returns the shared {DDPlugin::Registry} instance, creating it if none
# exists yet.
#
# @return [DDPlugin::Registry] The shared plugin registry
def self.instance
@instance ||= new
end
# @api private
def initialize
@identifiers_to_classes = Hash.new { |h, k| h[k] = {}.dup }
@classes_to_identifiers = Hash.new { |h, k| h[k] = {}.dup }
end
# Registers the given class as a plugin.
#
# @param [Class] root_class The root class of the class to register
#
# @param [Class] klass The class to register
#
# @param [Symbol] identifiers One or more symbols identifying the class
#
# @return [void]
def register(root_class, klass, *identifiers)
identifiers.map(&:to_sym).each do |identifier|
@classes_to_identifiers[root_class][klass] ||= []
@identifiers_to_classes[root_class][identifier] = klass
@classes_to_identifiers[root_class][klass] << identifier
end
end
# @param [Class] root_class The root class of the class to find the
# identifiers for
#
# @param [Class] klass The class to get the identifiers for
#
# @return [Array<Symbol>] The identifiers for the given class
def identifiers_of(root_class, klass)
@classes_to_identifiers[root_class] ||= {}
@classes_to_identifiers[root_class].fetch(klass, [])
end
# Finds the class that is a descendant of the given class and has the given
# identifier.
#
# @param [Class] root_class The root class of the class to return
#
# @param [Symbol] identifier The identifier of the class to return
#
# @return [Class, nil] The class with the given identifier
def find(root_class, identifier)
identifier = identifier.to_sym
@identifiers_to_classes[root_class] ||= {}
@identifiers_to_classes[root_class][identifier]
end
# Returns all classes that are registered descendants of the given class.
#
# @param [Class] root_class The root class of the class to return
#
# @return [Enumerable<Class>] A collection of registered classes
def find_all(root_class)
@identifiers_to_classes[root_class] ||= {}
@identifiers_to_classes[root_class].values.uniq
end
end
end
|
