1 files changed, 104 insertions, 0 deletions
diff --git a/railties/lib/generators.rb b/railties/lib/generators.rb
new file mode 100644
index 0000000000..c97801dea8
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+++ b/railties/lib/generators.rb
@@ -0,0 +1,104 @@
+activesupport_path = "#{File.dirname(__FILE__)}/../../activesupport/lib"
+$:.unshift(activesupport_path) if File.directory?(activesupport_path)
+require 'active_support/all'
+
+# TODO Use vendored Thor
+require 'rubygems'
+gem 'josevalim-thor'
+require 'thor'
+
+$:.unshift(File.dirname(__FILE__))
+require 'rails/version' unless defined?(Rails::VERSION)
+
+require 'generators/base'
+require 'generators/named_base'
+
+module Rails
+  module Generators
+    # Remove builtin generators.
+    #
+    def self.builtin
+      Dir[File.dirname(__FILE__) + '/generators/*/*'].collect do |file|
+        file.split('/')[-2, 2]
+      end
+    end
+
+    # Remove the color from output.
+    #
+    def self.no_color!
+      Thor::Base.shell = Thor::Shell::Basic
+    end
+
+    # Receives a namespace and tries different combinations to find a generator.
+    #
+    # ==== Examples
+    #
+    #   find_by_namespace :webrat, :rails, :integration
+    #
+    # Will search for the following generators:
+    #
+    #   "rails:generators:webrat", "webrat:generators:integration", "webrat"
+    #
+    # If the namespace has ":" included we consider that a absolute namespace
+    # was given and the lookup above does not happen. Just the name is searched.
+    #
+    # Finally, it deals with one kind of shortcut:
+    #
+    #   find_by_namespace "test_unit:model"
+    #
+    # It will search for generators at:
+    #
+    #   "test_unit:generators:model", "test_unit:model"
+    #
+    def self.find_by_namespace(name, base=nil, context=nil)
+      name, attempts = name.to_s, []
+
+      attempts << "#{base}:generators:#{name}"    if base && name.count(':') == 0
+      attempts << "#{name}:generators:#{context}" if context && name.count(':') == 0
+      attempts << name.sub(':', ':generators:')   if name.count(':') == 1
+      attempts << name
+
+      attempts.each do |namespace|
+        klass = Thor::Util.find_by_namespace(namespace)
+        return klass if klass
+      end
+
+      nil
+    end
+
+    # Show help message with available generators.
+    #
+    def self.help
+      rails = Rails::Generators.builtin.map do |group, name|
+        name if group == "rails"
+      end
+      rails.compact!
+      rails.sort!
+
+      puts "Please select a generator."
+      puts "Builtin: #{rails.join(', ')}."
+
+      # TODO Show others after lookup is implemented
+      # puts "Others: #{others.join(', ')}."
+    end
+
+    # Receives a namespace, arguments and the behavior to invoke the generator.
+    # It's used as the default entry point for generate, destroy and update
+    # commands.
+    #
+    def self.invoke(namespace, args=ARGV, behavior=:invoke)
+      # Load everything right now ...
+      builtin.each do |group, name|
+        require "generators/#{group}/#{name}/#{name}_generator"
+      end
+
+      if klass = find_by_namespace(namespace, "rails")
+        args << "--help" if klass.arguments.any? { |a| a.required? } && args.empty?
+        klass.start args, :behavior => behavior
+      else
+        puts "Could not find generator #{namespace}."
+      end
+    end
+  end
+end
+