Published on 2007-04-29 20:25:59
Server based AJAX is a recent addition to the AJAX frameworks arena and it basically changes the way we think about AJAX applications. It introduces a concept of server based computing for web applications where your code runs entirely on the server and reflecting changes to the client. This concept is used widely in remote desktop or application streaming software, but has not been until now available for web developers.
The server based AJAX concept provides great benefits for developers in terms of productivity, manageability and usability. Currently the only available framework implementing full server based AJAX is Visual WebGui which provides full WinForms like API and design time capabilities for developing web applications. While it sounds very much like Google's GWT it is not, as it does not serialize the application code to JavaScript but rather uses it in runtime on the server and reflecting the UI to the client. This means that you have what can be called an "empty client" that is managed entirely by the server. Client events are sent to the server that in turn, return its update commands to the client reflecting changes made to the UI on the server. This process can be optimized in various scenarios explicitly to reduce the amount of server callbacks and bandwidth consumption, making the end result as responsive as standard AJAX applications.
There are some down sides to the server based AJAX concept, mainly in terms of scalability, as you are utilizing a server session to run your application but when applied to enterprise applications, rather then Amazon sized sites, you get a very nice ROI that you would not get in any other architecture. In terms of responsiveness and performance one would think that this concept lacks, but the opposite is the case, as the server uses fewer resources in terms of CPU and IO as it does not have to receive/return large blobs and most important does not need to construct and deconstruct the application classes on every request. Also as said before there are many optimizations that can be applied to reduce server callbacks and bandwidth consumption.
The server based AJAX concepts may just be the solution for enterprise AJAX applications as it provides these applications with the best of both worlds. Having a responsive, rich AJAX UI that behaves pretty much like desktop UI, but still maintaining the productivity, IP protection, and security of running the application on server side provides a compelling offering for enterprises.
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