IT-eye

Client Server 2.0 is the next logical step that started with AJAX and RIA. It is Client Server but based on open standards: html, javascript, css and services. The client is completely responsible for creating the user interface. All dynamic parts are generated using javascript in the browser. Applications servers will serve static html, javascript, and css. But more importantly, they will host the services used by the javascript clients. So the main role of application servers in this model is to act as SOA containers.

The following image illustrates the position of Client Server 2.0 with respect to other application architectures. The eighties saw the move from terminal applications to client server applications, enabling users to take advantage of the increased power of their pc’s. The nineties saw the rise of html applications, taking advantage of open standards, enabling everybody to easily use applications everywhere. And now we’re again at a point where we can take full advantage of the power of the client workstation, but with the added benefit of using open standards, so everybody, anywhere can easily use them.

The following image illustrates the overall Client Server 2.0 architecture. You need a server that can host the static javascript, css and html files. Then you have a browser where the actual client is running. Javascript will be used to update the user interface as needed. And you have SOA containers that host the services used by the client application.

I’ve created some applications using the technology stack illustrated in the next image, and have been very impressed with the productivity you can achieve this way. JQuery hides most of the browser differences, and makes most javascript tasks very easy. There are also a lot of existing JQuery plugins available, from complex datagrids, to charting, to maps integration. Creating custom JQuery/javascript components is also a lot simpler than creating components that works partly on the server and partly on the client. Huge difference with for example JSF. And finally Grails is a very productive framework for creating RESTfull JSON services.

So, there you have it: Client Server 2.0 – Standards based browser applications, without a web-framework on an application server, talking to services hosted by SOA containers.