Teach some AR to the application generator

  Example:

    $ cramp new liveblog --with-active-record

CHANGELOG

@@ -1,5 +1,15 @@
 == 0.14 Asgard (Unreleased)
 
+* Add an option to the application generator for configuring async Active Record.
+
+  Example:
+
+    $ cramp new liveblog --with-active-record
+
+    or
+
+    $ cramp new liveblog -M
+
 * Barebone application generator using Thor.
 
   Example:

lib/cramp/generators/application.rb

@@ -10,6 +10,7 @@ class Application < Thor::Group
       include Thor::Actions
 
       argument :application_path, :type => :string
+      class_option :with_active_record, :type => :boolean, :aliases => "-M", :default => false, :desc => "Configures Active Record"
 
       def initialize(*args)
         raise Thor::Error, "No application name supplied. Please run: cramp --help" if args[0].blank?
@@ -44,6 +45,7 @@ def create_config
 
         inside "config" do
           template "routes.rb"
+          template 'database.yml' if active_record?
         end
       end
 
@@ -58,6 +60,10 @@ def create_home_action
 
       protected
 
+      def active_record?
+        options[:with_active_record]
+      end
+
       def app_name
         @app_name ||= File.basename(destination_root)
       end

lib/cramp/generators/templates/application/Gemfile

@@ -9,8 +9,13 @@ gem 'thin'
 gem 'http_router'
 
 # For async Active Record models
-# gem 'mysql2'
+<% if active_record? -%>
+gem 'mysql2', '~> 0.2.7'
+gem 'activerecord'
+<% else -%>
+# gem 'mysql2', '~> 0.2.7'
 # gem 'activerecord'
+<% end -%>
 
 # Using Fibers + async callbacks to emulate synchronous programming
 # gem 'em-synchrony'

lib/cramp/generators/templates/application/app/actions/base_action.rb

@@ -1,2 +1,6 @@
 class BaseAction < Cramp::Action
+  <% if active_record? %>use_fiber_pool do |pool|
+    # Called everytime after a fiber is done with a callback
+    pool.generic_callbacks << proc { ActiveRecord::Base.clear_active_connections! }
+  end<% end %>
 end

lib/cramp/generators/templates/application/application.rb

@@ -5,16 +5,32 @@
 
 require 'cramp'
 require 'http_router'
+<% if active_record? -%>require 'active_record'<% end %>
 
 require './app/actions/base_action'
 require './app/actions/home_action'
 
 module <%= app_const_base %>
   class Application
 
+    def self.env
+      @_env ||= defined?(RACK_ENV) ? RACK_ENV : 'development'
+    end
+
     def self.routes
       @_routes ||= eval(File.read('./config/routes.rb'))
     end
+    <% if active_record? %>
+    def self.database_config
+      @_database_config ||= YAML.load(File.read('./config/database.yml')).with_indifferent_access
+    end
+    <% end -%>
+
+    # Initialize the application
+    def self.initialize!
+      <% if active_record? %>ActiveRecord::Base.configurations = <%= app_const %>.database_config
+      ActiveRecord::Base.establish_connection(<%= app_const %>.env)<% end %>
+    end
 
   end
 end

lib/cramp/generators/templates/application/config.ru

@@ -1,4 +1,5 @@
 require './application'
 
 # bundle exec thin --max-persistent-conns 1024 -V -R config.ru start
+<%= app_const %>.initialize!
 run <%= app_const %>.routes

lib/cramp/generators/templates/application/config/database.yml

@@ -0,0 +1,6 @@
+development:
+  adapter: em_mysql2
+  database: <%= app_name %>_development
+  host: localhost
+  username: root
+  pool: 100