SharePoint and Ajax Postback issue

SharePoint Server is a great application platform that has rich out of the box functionality. Building custom solutions on SharePoint may require a little more research to ensure that you are able to implement modern UI capabilities. One of the issues we found recently is that SharePoint in its native configuration does not support simultaneous postbacks.

Our design goal was to build web parts that behaved independently and that would issue postbacks as each part was loaded. This would allow the web page UI to load while the data was being fetched in the background.

Once we had built our Asp.Net user controls we found that they did not work as expected in a SharePoint enviornment. This relates to the way that Sharepoint handles post backs and a fix that Microsoft implemented to cater for double byte url's. Luckily the fix is quite easy to implement, that is once you have identifed the reason why subsequent post backs were failing.

Adding the following two lines of javascript code at the top of the web page solved the problem.

_spOriginalFormAction = document.forms[0].action;
_spSuppressFormOnSubmitWrapper=true;