Module: Rails::Decorators::Decorator

Defined in:
lib/rails/decorators/decorator.rb

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.decorate(*targets, &module_definition) ⇒ Object 



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
79
80
81
82
83
84
85
 
# File 'lib/rails/decorators/decorator.rb', line 14

def self.decorate(*targets, &module_definition)
  options = targets.extract_options!

  targets.each do |target|
    unless target.is_a?(Class)
      raise(
        InvalidDecorator,
        <<-eos.strip_heredoc

          Problem:
            You cannot decorate a Module
          Summary:
            Decoration only works with classes. Decorating modules requires
            managing load order, a problem that is very complicated and
            beyond the scope of this system.
          Resolution:
            Decorate multiple classes that include the module like so:
            `decorate Catalog::Product, Content::Page do`
        eos
      )
    end

    if target.name.to_s.end_with?('Helper')
      raise(
        InvalidDecorator,
        <<-eos.strip_heredoc

          Problem:
            Rails::Decorators doesn't work with helpers.
          Summary:
            Rails does some magic with helpers which in certain cases
            causes decoration to not work.
          Resolution:
            Create a new helper and in a `to_prepare` block, use
            ActionPack's `helper` method to include the helper, e.g.
            `MyEngine::ApplicationController.helper(MyEngine::BlogsHelper)`
        eos
      )
    end

    decorator_name = "#{options[:with].to_s.camelize}#{target.to_s.demodulize}Decorator"

    if target.const_defined?(decorator_name)
      # We are probably reloading in Rails development env if this happens
      next if !Rails.application.config.cache_classes

      raise(
        InvalidDecorator,
        <<-eos.strip_heredoc

          Problem:
            #{decorator_name} is already defined in #{target.name}.
          Summary:
            When decorating a class, Rails::Decorators dynamically defines
            a module for prepending the decorations passed in the block. In
            this case, the name for the decoration module is already defined
            in the namespace, so decorating would redefine the constant.
          Resolution:
            Please specify a unique `with` option when decorating #{target.name}.
        eos
      )
    end

    mod = Module.new do
      extend Rails::Decorators::Decorator
      module_eval(&module_definition)
    end

    target.const_set(decorator_name, mod)
    mod.decorates(target)
  end
end

.loader(roots) ⇒ Object 



4
5
6
7
8
9
10
11
12
 
# File 'lib/rails/decorators/decorator.rb', line 4

def self.loader(roots)
  Proc.new do
    roots.each do |root|
      decorators = Dir.glob("#{root}/app/**/*.#{Rails::Decorators.extension}")
      decorators.sort!
      decorators.each { |d| require_dependency(d) }
    end
  end
end

Instance Method Details

#class_methods(&class_methods_module_definition) ⇒ Object Also known as: module_methods 



105
106
107
108
 
# File 'lib/rails/decorators/decorator.rb', line 105

def class_methods(&class_methods_module_definition)
  mod = const_set(:ClassMethodsDecorator, Module.new)
  mod.module_eval(&class_methods_module_definition)
end

#decorated(&block) ⇒ Object 



101
102
103
 
# File 'lib/rails/decorators/decorator.rb', line 101

def decorated(&block)
  instance_variable_set(:@_decorated_block, block)
end

#decorates(klass) ⇒ Object 



111
112
113
 
# File 'lib/rails/decorators/decorator.rb', line 111

def decorates(klass)
  klass.send(:prepend, self)
end

#prepend_features(base) ⇒ Object 



87
88
89
90
91
92
93
94
95
96
97
98
99
 
# File 'lib/rails/decorators/decorator.rb', line 87

def prepend_features(base)
  super

  if const_defined?(:ClassMethodsDecorator)
    base
      .singleton_class
      .send(:prepend, const_get(:ClassMethodsDecorator))
  end

  if instance_variable_defined?(:@_decorated_block)
    base.class_eval(&@_decorated_block)
  end
end