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Q: What are the differences between an ISAPI applications and a filters? A: ISAPI applications are called only on demand, if a request explicitly points to the DLL. Hence, in the most common case - of processing all normal
requests, the additional overhead of a filter will not be incurred. ISAPI Filters provide call backs at each stage of the processing. One of the stages is the authentication process. You need to set up a filter to watch for the filter notification SF_NOTIFY_AUTHENTICATION. You can use ISA Filter to scan the documents on the fly and serve some custom information. However, this may slowdown the server heavily since the amount of work done is going to be large. If you are just interested in adding some information to each page, that can be implemented using a separate call out to ISAPI application dll rather than Filter. For example: this will serve better to insert page counters or whatever. - Murali Krishnan |