GWT with RubyOnRails backend glued together with Maven/JRuby

let's first look a the different parts involved:

• GWT (Google Webtoolkit) comes with "generators" which focus on ANT as build system
• Ruby on Rails has its way of starting a new application and scaffold models and their views
• JRuby allows to use java side by side with ruby and allows to run a rails application in a java servlet engine
• Maven is a build tool mainly for java project. but with a set of jruby maven plugins (j)ruby project can be managed almost as well. with the advent of Roo the maven support for GWT drastically improved.
• Ruby-Maven Gem tries to bridge the ruby and maven world by offering a more concise commandline interface. as gem it is easy to install from ruby point of view.
• RestyGWT is a GWT generator for REST services and JSON encoded data transfer objects.

walkthrough of an example

first you need ruby-maven installed. when you use it with ruby (MRI) then you also need java >1.5 installed or use jruby. please update the gem if already installed:

jruby -S gem install ruby-maven

or

ruby -S gem install ruby-maven

using MRI will improve startup time drastically.

create a rails application

with ruby-maven there are new commands rmvn, gwt and jetty-run with this you can create a new rails application with GWT setup like this

gwt new my_app com.example

with this you have already a GWT application with EntryPoint and could be started but does not do much. the class layout within the GWT client package:

src/main/java/com/example/client/
  ├── client
  │   ├── ActivityPlaceActivityMapper.java
  │   ├── ActivityPlace.java
  │   ├── managed
  │   │   ├── ActivityFactory.java
  │   │   ├── MyAppModule.java
  │   │   └── MyAppPlaceHistoryMapper.java
  │   └── MyAppEntryPoint.java
  └── MyApp.gwt.xml

scaffold a resource with model, controller, gwt-model, etc

go into the created application (or any existing rails app)

cd my_app

now you can scaffold a model (currently two steps are required for this)

rmvn rails generate scaffold user name:string

this creates a rails like structure following the GWT activity/place/view pattern:

src/main/java/com/example/client/
├── activities
│   └── UserActivity.java
├── models
│   └── User.java
├── places
│   ├── UserPlace.java
│   └── UserPlaceTokenizer.java
├── restservices
│   └── UsersRestService.java
└── views
    ├── UserViewImpl.java
    ├── UserView.java
    └── UserView.ui.xml

finally you can run the application.

start the GWT development shell

before running the application you need to migrate the database

rmvn rake db:migrate

and start the GWT development shell

gwt run

the start url for the new resource is

http://localhost:8888/MyApp.html?gwt.codesvr=127.0.0.1:9997#users


run the rails server

to run the application with default webrick you need first to compile the GWT part

gwt compile

the compiler will output the GWT app in public/my_app and then start the webrick. the start url is http://localhost:3000/MyApp.html#users

rmvn rails server

or if you prefer the jetty server with http://localhost:8080/MyApp.html#users

rmvn jetty:run

build the war file

rmvn package 

the war file can be found in the target directory

more

you can also use proper maven3 instead of ruby-maven but the command-line-interface of maven is much more clumsy though the functionality is the same.

more up to date infos are here: https://github.com/mkristian/rails-resty-gwt

enjoy !
any comment and/or suggestion is welcome.