Enabling Ajax in MOSS 2007

Ajax greatly enhance any web application by reducing postback of ASP.NET pages. This instantly gives better user experience with the Ajax-enabled web application. Best of all, implementing it is fairly straight forward. That is, if SharePoint 2007 is not in the picture.

If you're building a ajax web application that sits on top of MOSS 2007, there's a couple of things you need to set:

If your custom app uses any of the SharePoint master page (such as default.master), ensure the wss user control Welcome is removed:

<wssuc:welcome id="IdWelcome" runat="server" enableviewstate="false"></wssuc:Welcome> This affects Ajax postbacks. Removing it will partially fix the problem. One-time ajax postback works, subsequently, it will fail. Secondly, the other change required is at LAYOUTS\1033\init.js file 1. Look for javascript function _spFormOnSubmitWrapper. 2. Under “if (_spFormOnSubmitCalled)” code block, remove/comment the “return false;” code. I'm not sure whether making this change would affect SharePoint, but so far seems ok. Do use this at your own risk though. Hopefully there's a fix for this in SharePoint soon so that Ajax will work without this kind of hack.

Reference made to Vincent Rothwell's blog: http://blog.thekid.me.uk/2007/01/19/using-aspnet-ajax-with-sharepoint-moss-2007-2/