Plugins

README.rdoc

@@ -189,6 +189,31 @@ There are a handful of exciting new additions in version 1.0 of <tt>vestal_versi
     >> @user.version
     => 2
 
+* Plugin modules.  By setting <tt>:plugins</tt> to a module, or array of modules, you can mixin your own code.
+
+   module MyCustomPlugin
+     extend ActiveSupport::Concern
+     included do
+       class_attribute :plugged_in_model
+       VestalVersions::Version.class_eval{ include MyCustomPluginMethods}
+     end
+   end
+   module MyCustomPluginMethods
+     extend ActiveSupport::Concern
+     included do
+       class_attribute :plugged_in_version
+     end
+   end
+
+   class User < ActiveRecord::Base
+     versioned :plugins => MyCustomPlugin
+   end
+
+   >> User.respond_to? :plugged_in_model
+   => true
+   >> VestalVersions::Version.respond_to? :plugged_in_version
+   => true
+
 == Thanks!
 
 Thank you to all those who post {issues and suggestions}[http://github.com/laserlemon/vestal_versions/issues]. And special thanks to:
@@ -197,4 +222,4 @@ Thank you to all those who post {issues and suggestions}[http://github.com/laser
 * snaury[http://github.com/snaury], who helped out early on with the <tt>between</tt> association method, the <tt>:dependent</tt> option and a conflict from using a method called <tt>changes</tt>
 * sthapit[http://github.com/sthapit], who was responsible for the <tt>:only</tt> and <tt>:except</tt> options as well as showing me that I'm a dummy for storing a useless first version
 
-To contribute to <tt>vestal_versions</tt>, please fork, hack away in the integration[http://github.com/laserlemon/vestal_versions/tree/integration] branch and send me a pull request. Remember your tests!
+To contribute to <tt>vestal_versions</tt>, please fork, hack away in the integration[http://github.com/laserlemon/vestal_versions/tree/integration] branch and send me a pull request. Remember your tests!

lib/vestal_versions.rb

@@ -37,6 +37,7 @@ module VestalVersions
   autoload :Control
   autoload :Creation
   autoload :Deletion
+  autoload :Plugins
   autoload :Options
   autoload :Reload
   autoload :Reset
@@ -102,6 +103,9 @@ module ClassMethods
     #   is called on any symbols given and the resulting procs are called, passing in the object
     #   itself. If an array is given and any element evaluates as +true+, the version creation will
     #   be skipped.
+    # * <tt>:plugins</tt>: This option allows you to load additional functionality from a custom 
+    #   module or array of modules, allowing you to extend functionality of both the Version model 
+    #   and the +versioned+ models.  See VestalVersions::Users for an example plugin class.
     def versioned(options = {}, &block)
       return if versioned?
 
@@ -116,6 +120,7 @@ def versioned(options = {}, &block)
       include VersionTagging
       include Reload
       include Deletion
+      include Plugins
 
       prepare_versioned_options(options)
       has_many :versions, options, &block

lib/vestal_versions/plugins.rb

@@ -0,0 +1,29 @@
+module VestalVersions
+  # Allows custom modules to be loaded based on given <tt>:plugins</tt> option
+  module Plugins
+    extend ActiveSupport::Concern
+    # Class methods on ActiveRecord::Base to prepare the <tt>:plugins</tt> option.
+    module ClassMethods
+      # After the original +prepare_versioned_options+ method cleans the given options, this alias
+      # also extracts the <tt>:plugins</tt> and includes them if required
+      def prepare_versioned_options(options)
+        result = super(options)
+
+        # Pull the plugins out of options, constantize or ensure they're a Module, otherwise drop them
+        plugins = Array(result.delete :plugins).map{|p|
+          if p.is_a? Module
+            p
+          elsif p.is_a? String
+            p.constantize
+          end
+        }.flatten.compact
+
+        # Include requested plugins
+        plugins.each {|p| include p unless self.included_modules.include? p}
+        self.vestal_versions_options[:plugins] = plugins
+
+        result
+      end
+    end
+  end
+end

spec/support/plugins.rb

@@ -0,0 +1,16 @@
+module MyCustomPlugin
+  extend ActiveSupport::Concern
+
+  included do
+    class_attribute :plugged_in_model
+    VestalVersions::Version.class_eval{ include MyCustomPluginMethods}
+  end
+end
+
+module MyCustomPluginMethods
+  extend ActiveSupport::Concern
+
+  included do
+    class_attribute :plugged_in_version
+  end
+end

spec/vestal_versions/options_spec.rb

@@ -8,6 +8,13 @@
     before do
       VestalVersions::Version.config.clear
       VestalVersions::Version.config.class_name = 'MyCustomVersion'
+      User.prepare_versioned_options(options.dup)
+    end
+
+    it 'stores options in a class variable' do
+      User.vestal_versions_options.slice(:class_name).should == {
+        :class_name => 'MyCustomVersion'
+      }
     end
 
     it 'has symbolized keys' do
@@ -20,7 +27,6 @@
         :class_name => 'MyCustomVersion'
       }
     end
-
   end
 
   context 'default configuration options' do

spec/vestal_versions/plugins_spec.rb

@@ -0,0 +1,25 @@
+require 'spec_helper'
+
+describe VestalVersions::Plugins do
+  context 'when a plugin is requested' do
+    before do
+      User.prepare_versioned_options(:plugins => 'MyCustomPlugin')
+    end
+
+    it 'stores plugins the options hash' do
+      User.vestal_versions_options[:plugins].should == [MyCustomPlugin]
+    end
+
+    it 'converts strings to modules' do
+      User.vestal_versions_options[:plugins].all?{|p| p.is_a?(Module)}
+    end
+
+    it 'modifies versioned models if requested' do
+      User.should respond_to(:plugged_in_model)
+    end
+
+    it 'modifies Version if requested' do
+      VestalVersions::Version.should respond_to(:plugged_in_version)
+    end
+  end
+end