Start the appengine-tools gem

lib/appengine-tools/rack.rb

+#!/usr/bin/ruby1.8 -w
+#
+# Copyright:: Copyright 2009 Google Inc.
+# Original Author:: Ryan Brown (mailto:ribrdb@google.com)
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+require 'rexml/document'
+require 'rexml/formatters/pretty'

[woodie, 2009/07/03 00:59:21]

not used here anymore

+
+module AppEngine
+  module Rack
+    class Resources
+      def initialize
+        @includes = []
+        @excludes = []
+      end
+    
+      def include(glob)
+        @includes << glob
+      end
+    
+      def exclude(glob)
+        @excludes << glob
+      end
+    
+      def to_xml(xml, type)
+        resources = REXML::Element.new(type) 
+        @includes.each do |path|
+          resources.add_element('include').add_attribute('path', path)
+        end
+        @excludes.each do |path|
+          resources.add_element('exclude').add_attribute('path', path)
+        end
+        xml.add_element(resources) 
+      end
+    end
+  
+    class PropertyMap < Hash
+      def to_xml(xml)
+        unless empty?
+          sys = REXML::Element.new('system-properties') 
+          each do |name, value|
+            sys.add_element('property').
+                add_attributes( { "name" => name, "value" => value } )
+          end
+          xml.add_element(sys) 
+        end
+      end
+    end
+  
+    class EnvVarMap < Hash
+      def to_xml(xml)
+        unless empty?
+          env = REXML::Element.new('env-variables') 
+          each do |name, value|
+            env.add_element('env-var').
+                add_attributes( { "name" => name, "value" => value } )
+          end
+          xml.add_element(env) 
+        end
+      end    
+    end
+  
+    class RackApplication

[woodie, 2009/07/03 02:39:57]

# I liked my force-to-string mod, but with your way
# you should only generate the reader for :version 

      attr_accessor :application
      attr_reader :version, :static_files, :resource_files
      attr_reader :system_properties, :environment_variables
      attr_writer :ssl_enabled, :sessions_enabled

+      attr_accessor :application, :version
+      attr_writer :ssl_enabled, :sessions_enabled
+      attr_reader :system_properties, :environment_variables
+      attr_reader :static_files, :resource_files
+    
+      def initialize
+        @version = '1'
+        @system_properties = PropertyMap[ 'os.arch' => '',
+                         'jruby.management.enabled' => 'false' ]
+        @environment_variables = EnvVarMap.new
+        @static_files = Resources.new
+        @resource_files = Resources.new
+      end
+    
+      def sessions_enabled?
+        @sessions_enabled
+      end
+    
+      def ssl_enabled?
+        @ssl_enabled
+      end
+      
+      def version=(version)
+        @version = version.to_s
+      end
+    
+      def configure(options={})
+        [:system_properties, :environment_variables].each do |key|
+          self.send(key).merge!(options.delete(key)) if options[key]
+        end
+        options.each { |k,v| self.send("#{k}=", v) }
+      end
+    
+      def to_xml

[woodie, 2009/07/03 00:59:21]

It may be more appropriate to use doc

doc = REXML::Document...

+        xml = REXML::Document.new.add_element('appengine-web-app')
+        xml.add_attribute('xmlns','http://appengine.google.com/ns/1.0')
+        xml.add_element('application').add_text(application)
+        xml.add_element('version').add_text(version)
+        xml.add_element('public-root').add_text('/public')
+        static_files.to_xml(xml, 'static-files')
+        resource_files.to_xml(xml, 'resource-files')
+        system_properties.to_xml(xml)
+        environment_variables.to_xml(xml)
+        if sessions_enabled?
+          xml.add_element('sessions-enabled').add_text('true')
+        end
+        if ssl_enabled?
+          xml.add_element('ssl-enabled').add_text('true')
+        end
+        return xml
+      end
+    end
+  
+    class << self
+      def app
+        @app ||= RackApplication.new
+      end
+
+      def configure(options={})
+        self.app.configure(options)
+      end
+
+      def environment
+        if $servlet_context
+          if $servlet_context.server_info =~ %r{^Google App Engine Development/}
+            "development"
+          elsif $servlet_context.server_info =~ %r{^Google App Engine/}
+            "production"
+          end
+        end
+      end
+    end
+  end
+end
+