(This was originally published in Bloglines on December 22, 2005)

(This is a comment to the post Ajax: Where should my business logic sit?)

Of course, any software engineering theory dictates that any AJAX should have no trace of business logic, but that this one must be limited to the server. Any good developer will tell you that one should put all of your logic in server-side web services, and handle only the presentation issues on the AJAX client side.

Also of course, the ability of creating business logic in a simple development environment like Javascript will lead in practice to the existence of a large number of applications with all of its business logic in the client side part. Just have a look at the number of applications existing now that have input validations only in the client side, and have the server side open to any client side mischief.

This is one of the problems I see in all the fuzz around AJAX. In my view, Javascript is not a good, stable, reliable environment for running professional applications. In my experience, any average development team devoted to Javascript will end up creating an unmanageable mess. It is not that it is not possible to do it in the right way: it is just that the average team won't. One just has to look to all the problems JSP has created to see this (if instead of just copying Microsoft's ASP with JSP Sun would have come up with a decent component-oriented framework for creating web views -which was perfectly feasible at the time-, web development would be a lot more easier now. Then, Java trailed MS again in this, with JSF).

I think that currently there is much more hype in AJAX than practical stuff. Although all the frenzy is also good, since it draws the attention and it is a first step. A first step towards a good computing platform to deploy client-side applications to the web: what Java applets should have been and are not because of several different reasons. Something with the robustness of Java (or .Net), the appeal and speed of Flash, and the convenience and universal availability of Javascript.

Some day there will be such a platform, well beyond AJAX. However, it will be also thanks to AJAX.