Building an EMR application with Google Web Toolkit

My company provides Revenue cycle management and Practice Management services to doctors. The platform was built using Java Servlet technology and has evolved into a fairly complex application over a decade. We were adding on additional services to our application - Electronic Medical Records and decided on GWT framework for this new clinical application. We have been watching GWT progress on and off for over a year and late last year decided to take the plunge - and we are glad we did. There a number of reasons why we chose Google Web Toolkit. The overriding factor being that managing Javascript was getting out of hand. GWT provides a really elegant way to "modularize" javascript and allows our development team to scale better.

We benefitted a lot from the vast amount of GWT articles, presentations and hope that our experience would benefit other future or current GWT developers.

In the next set of posts, I will describe how we implemented

a) The Command Pattern described by Ray Ryan

Our implementation is somewhat different than a number of posts I have seen on implementing this design pattern.

b) Security and Single Sign-on - Ability to control access to Methods on the RPC interface.

Our existing application had a framework to control access to - Object/Method to a given user role and we wanted to use the same authentication framework.

c) Cross Site RPC calls - getting around the restriction of Same Origin Policy.

Using Cross-Origin Resource Sharing

Most browsers support the CORS spec except for Microsoft Internet explorer - which supports XDomainRequest. Explain how we integrated Cross Site RPC into GWT to support IE as well.