lib/module_creation_helper/extensions/module.rb @@ -29,10 +29,8 @@ you will want to associate a runtime class with an actual name. Traditionally, you would create new classes like so: - >> c = Class.new - => #<Class:0x480e388> - >> Object.const_set('Foo', c) - => Foo + c = Class.new # => #<Class:0x480e388> + Object.const_set('Foo', c) # => Foo Although this isn't very hard, there are two problems: (1) It's a repetitive process that should be DRYed. @@ -50,9 +48,9 @@ To understand the second problem, consider the following: When a class inherits from Foo, Ruby will invoke the +inherited+ callback. For example, - >> c = Class.new(Foo) - inherited class: #<Class:0x47fb92c>, name: - => #<Class:0x47fb92c> + c = Class.new(Foo) + # inherited class: #<Class:0x47fb92c>, name: + # => #<Class:0x47fb92c> As you can see from output in this example, since the class has not yet been assigned to a constant, it is anonymous and does not yet have a name. @@ -67,9 +65,9 @@ Class since Class inherits from Module. Using the same example as before, - >> c = Class.create('Bar', :superclass => Foo) - inherited class: Bar, name: Bar - => Bar + c = Class.create('Bar', :superclass => Foo) + # inherited class: Bar, name: Bar + # => Bar As you can see, the name of the class is now available during the +inherited+ callback and is automatically assigned to the 'Bar' constant in Object. @@ -79,24 +77,24 @@ callback and is automatically assigned to the 'Bar' constant in Object. In addition to specifying the superclass, you can also specify the parent module/class like so: - >> c = Class.create('Bar', :superclass => Foo, :parent => MyModule) - inherited class: MyModule::Bar, name: MyModule::Bar - => MyModule::Bar + c = Class.create('Bar', :superclass => Foo, :parent => MyModule) + # inherited class: MyModule::Bar, name: MyModule::Bar + # => MyModule::Bar === Defining class/module methods As you normally could when creating a new class, you can provide an additional block that defines the body of the class. For example, - >> c = Class.create('Bar', :superclass => Foo, :parent => MyModule) do - ?> def say_hello - ?> 'hello' - ?> end - ?> end - inherited class: MyModule::Bar, name: MyModule::Bar - => Bar - >> Bar.new.say_hello - => "hello" + c = Class.create('Bar', :superclass => Foo, :parent => MyModule) do + def say_hello + 'hello' + end + end + # inherited class: MyModule::Bar, name: MyModule::Bar + # => Bar + Bar.new.say_hello + # => "hello" == Dependencies README.rdoc @@ -1,60 +1 @@ -module PluginAWeek #:nodoc: - module ModuleCreationHelper - # Creates a new module with the specified name. This is essentially the - # same as actually defining the module like so: - # - # module NewModule - # end - # - # or as a class: - # - # class NewClass < SuperKlass - # end - # - # Configuration options: - # * +superclass+ - The class to inherit from. This only applies when using Class#create. Default is Object. - # * +parent+ - The class/module that contains this module. Default is Object. - # - # Examples: - # - # Module.create('Foo') # => Foo - # Module.create('Bar', :parent => Foo) # => Foo::Bar - # Class.create('Waddle') # => Waddle - # Class.create('Widdle', :parent => Waddle) # => Waddle::Widdle - # Class.create('Woddle', :superclass => Waddle::Widdle, :parent => Waddle) # => Waddle::Woddle - # Waddle::Woddle.superclass # => Waddle::Widdle - def create(name, options = {}, &block) - options.assert_valid_keys( - :superclass, - :parent - ) - raise ArgumentError, 'Modules cannot have superclasses' if options[:superclass] && self.to_s == 'Module' - - options.reverse_merge!( - :superclass => Object, - :parent => Object - ) - parent = options[:parent] - superclass = options[:superclass] - - if superclass != Object - superclass = " < ::#{superclass}" - else - superclass = '' - end - - parent.class_eval <<-end_eval - #{self.to_s.downcase} #{name}#{superclass} - end - end_eval - - mod = parent.const_get(name) - mod.class_eval(&block) if block_given? - mod - end - end -end - -Module.class_eval do - extend PluginAWeek::ModuleCreationHelper -end +require 'module_creation_helper/extensions/module' lib/module_creation_helper.rb cdd8b52668bad5d79af6d933e3004f7e49598272 Aaron Pfeifer aaron.pfeifer@gmail.com http://github.com/pluginaweek/module_creation_helper/commit/42ee1210fc75b76adbb8aa0a077db36b6aafdb3b 42ee1210fc75b76adbb8aa0a077db36b6aafdb3b 2008-07-05T10:10:27-07:00 2008-07-05T10:10:27-07:00 Reorganize core extensions into a separate module Update format of examples ea5707e0b56884ab9e0cf477d32f35db3ffd3499 Aaron Pfeifer aaron.pfeifer@gmail.com