Articles

ISAPI using Delphi? Check out ISAPI Filter Component to write ISAPI filters the visual way, in Pascal, that is “The Delphi way”.

ISAPI is the application programming interface to extend the functionality of IIS, Microsoft Internet Information Server. IIS supports many scripting languages such as ASP, ASP.NET, PHP, JSP. However, for certain tasks that are orthogonal to a specific http request, an ISAPI filter is the best match. ISAPI filters are native DLLs written in a native language. They become part of the IIS server and extend it’s functionality in ways that cannot be implemented using ASP.NET or other server side technologies.

For an incoming http request, an ISAPI Filter is invoked before ASP.NET, or any other server side programming layer. For outgoing http requests, ISAPI filters are invoked after ASP.NET has completed it’s execution. This order of events and scope of control gives the ISAPI filters a special priviledge to literally do whatever they want. ISAPI Filter is the gate keeper.
(more…)