It has been quite some time since my last post. Consequently, I have been busy, since the launch of WSS 3.0/MOSS 2007. On the contrary, I know that I could have posted at any time from any city during my travels. In any case, I have a duty to post my thoughts referencing the WSS 3.0 and MOSS 2007 technologies.
In my posting, titled: Intergration: WSS 2.0/WSS 3.0, ASP.NET 1.1/2.0 and IIS 6.0, I promised to set in motion discussions centered around the intergration of WSS 2.0/WSS 3.0 with IIS 6.0. Incidentally, that discussion is long overdue.
During my presentations, facilitations/training, I have a number of students asking questions about the differences between WSS 2.0/3.0 and SPS 2003/MOSS 2007. Furthermore, many students would like a firm understanding of the page request lifecycles. In any case, all would like to understand, “Behind the Scenes“. I thought long and hard about how to attack this subject in a fashion that would be beneficial to as many as possible.
First of all, I want to discuss the SharePointHandler - WSS 2.0/SPS 2003 - and Virtual Path Provider - WSS 3.0/MOSS 2007. In essence, I want to focus on the page request lifecycle for, both, WSS 2.0/SPS 2003 and WSS 3.0/MOSS 2007. For the most part, there are a number of articles, blogs and whitepapers out on the web that provide a solid overview of the page request lifecycle for both versions of SharePoint. I would recommend reviewing them all.
To begin, the SharePointHandler is an HTTP handler used to handle request for the WSS 2.0/SPS 2003 environment. During the install of WSS 2.0/SPS 2003, the ISAPI filter is added to the IIS 6.0. Hence, the ISAPI filter intercepts all page requests from IIS. The ISAPI filter is charged with determining the handler of a page request. For the most part, ASP.NET is the default handler for IIS. If the ISAPI filter determines that the page request is managed by WSS 2.0/SPS 2003, it forwards the request to the SharePointHandler.
In contrast, the Virtual Path Provider is the component that handles the page request for WSS 3.0/MOSS 2007 environment. Likewise, ASP.NET 2.0 retreives all page requests directly from IIS 6.0. ASP.NET 2.0 determines if the page request is destined for a Web Application, In another posting, i will extend our discussions referencing the retreival of pages from the site definitions/site templates versus the database.
In short, the processing of page requests have had a major overhall. In essence, the ISAPI fileter, found in WSS 2.0/SPS 2003, has been removed. It is not used to intercept page requests in the WSS 3.0/MOSS 2007 environment.