1 files changed, 81 insertions, 0 deletions
diff --git a/railties/lib/rails_generator/scripts.rb b/railties/lib/rails_generator/scripts.rb
new file mode 100644
index 0000000000..007980dcb5
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+++ b/railties/lib/rails_generator/scripts.rb
@@ -0,0 +1,81 @@
+require File.dirname(__FILE__) + '/options'
+
+module Rails
+  module Generator
+    module Scripts
+
+      # Generator scripts handle command-line invocation.  Each script
+      # responds to an invoke! class method which handles option parsing
+      # and generator invocation.
+      class Base
+        include Options
+        default_options :collision => :ask, :quiet => false
+
+        # Run the generator script.  Takes an array of unparsed arguments
+        # and a hash of parsed arguments, takes the generator as an option
+        # or first remaining argument, and invokes the requested command.
+        def run(args = [], runtime_options = {})
+          begin
+            parse!(args, runtime_options)
+
+            # Generator name is the only required option.
+            unless options[:generator]
+              usage if args.empty?
+              options[:generator] ||= args.shift
+            end
+
+            # Look up generator instance and invoke command on it.
+            Rails::Generator::Base.instance(options[:generator], args, options).command(options[:command]).invoke!
+          rescue => e
+            puts e
+            puts "  #{e.backtrace.join("\n  ")}\n" if options[:backtrace]
+            raise SystemExit
+          end
+        end
+
+        protected
+          # Override with your own script usage banner.
+          def banner
+            "Usage: #{$0} [options] generator [args]"
+          end
+
+          def usage_message
+            usage = "\nInstalled Generators\n"
+            Rails::Generator::Base.sources.each do |source|
+              label = source.label.to_s.capitalize
+              names = source.names
+              usage << "  #{label}: #{names.join(', ')}\n" unless names.empty?
+            end
+
+            usage << <<end_blurb
+
+More are available at http://rubyonrails.org/show/Generators
+  1. Download, for example, login_generator.zip
+  2. Unzip to directory #{Dir.user_home}/.rails/generators/login
+     to use the generator with all your Rails apps
+end_blurb
+
+            if Object.const_defined?(:RAILS_ROOT)
+              usage << <<end_blurb
+     or to #{File.expand_path(RAILS_ROOT)}/script/generators/login
+     to use with this app only.
+end_blurb
+            end
+
+            usage << <<end_blurb
+  3. Run generate with no arguments for usage information
+       #{$0} login
+
+Generator gems are also available:
+  1. gem list generator -s http://gems.rubyonrails.org
+  2. gem install login_generator -s http://gems.rubyonrails.org
+  3. #{$0} login
+
+end_blurb
+            return usage
+          end
+      end # Base
+
+    end
+  end
+end