1  require 'annotatable'
   2  require 'simpleton'
   3  require 'radiant/admin_ui'
   4 
   5  module Radiant
   6    class Extension
   7      include Simpleton
   8      include Annotatable
   9 
  10      annotate :version, :description, :url, :extension_name, :path
  11 
  12      attr_writer :active
  13      
  14      def active?
  15        @active
  16      end
  17      
  18      def root
  19        path.to_s
  20      end
  21      
  22      def migrated?
  23        migrator.new(:up, migrations_path).pending_migrations.empty?
  24      end
  25      
  26      def enabled?
  27        active? and migrated?
  28      end
  29      
  30      # Conventional plugin-like routing
  31      def routed?
  32        File.exist?(routing_file)
  33      end
  34      
  35      def migrations_path
  36        File.join(self.root, 'db', 'migrate')
  37      end
  38      
  39      def migrates_from
  40        @migrates_from ||= {}
  41      end
  42      
  43      def routing_file
  44        File.join(self.root, 'config', 'routes.rb')
  45      end
  46          
  47      def load_initializers
  48        Dir["#{self.root}/config/initializers/**/*.rb"].sort.each do |initializer|
  49          load(initializer)
  50        end
  51      end
  52      
  53      def migrator
  54        unless @migrator
  55          extension = self
  56          @migrator = Class.new(ExtensionMigrator){ self.extension = extension }
  57        end
  58        @migrator
  59      end
  60      
  61      def admin
  62        AdminUI.instance
  63      end
  64      
  65      def tab(name, options={}, &block)
  66        @the_tab = admin.nav[name]
  67        unless @the_tab
  68          @the_tab = Radiant::AdminUI::NavTab.new(name)
  69          before = options.delete(:before)
  70          after = options.delete(:after)
  71          tab_name = before || after
  72          tab_object = admin.nav[tab_name]
  73          if tab_object
  74            index = admin.nav.index(tab_object)
  75            index += 1 unless before
  76            admin.nav.insert(index, @the_tab)
  77          else
  78            admin.nav << @the_tab
  79          end
  80        end
  81        if block_given?
  82          block.call(@the_tab)
  83        end
  84        return @the_tab
  85      end
  86      alias :add_tab :tab
  87      
  88      def add_item(*args)
  89        @the_tab.add_item(*args)
  90      end
  91 
  92      # Determine if another extension is installed and up to date.
  93      #
  94      # if MyExtension.extension_enabled?(:third_party)
  95      #   ThirdPartyExtension.extend(MyExtension::IntegrationPoints)
  96      # end
  97      def extension_enabled?(extension)
  98        begin
  99          extension = (extension.to_s.camelcase + 'Extension').constantize
 100          extension.enabled?
 101        rescue NameError
 102          false
 103        end
 104      end
 105 
 106      class << self
 107 
 108        def activate_extension
 109          return if instance.active?
 110          instance.activate if instance.respond_to? :activate
 111          ActionController::Routing::Routes.add_configuration_file(instance.routing_file) if instance.routed?
 112          ActionController::Routing::Routes.reload
 113          instance.active = true
 114        end
 115        alias :activate :activate_extension
 116 
 117        def deactivate_extension
 118          return unless instance.active?
 119          instance.active = false
 120          instance.deactivate if instance.respond_to? :deactivate
 121        end
 122        alias :deactivate :deactivate_extension
 123 
 124        def define_routes(&block)
 125          ActiveSupport::Deprecation.warn("define_routes has been deprecated in favor of your extension's config/routes.rb",caller)
 126          route_definitions << block
 127        end
 128 
 129        def inherited(subclass)
 130          subclass.extension_name = subclass.name.to_name('Extension')
 131        end
 132 
 133        def route_definitions
 134          @route_definitions ||= []
 135        end
 136 
 137        def migrate_from(extension_name, until_migration=nil)
 138          instance.migrates_from[extension_name] = until_migration
 139        end
 140 
 141        # Expose the configuration object for init hooks
 142        # class MyExtension < ActiveRecord::Base
 143        #   extension_config do |config|
 144        #     config.after_initialize do
 145        #       run_something
 146        #     end
 147        #   end
 148        # end
 149        def extension_config(&block)
 150          yield Rails.configuration
 151        end
 152        
 153      end
 154    end
 155  end