Designing Fill-out Forms for Use with ISAPI Parse Map Macros

|  Overview |  How Do I

When a CHttpServer object receives a client request, it uses a set of macros called a parse map that map the request to the appropriate CHttpServer member functions. The client request can either be a server GET method or a server POST method. Other methods, like HEAD, are not supported. You can add your own support by overriding .

Authors of ISAPI forms are advised to use only the POST method because of browser inconsistencies, and because GET methods are limited to a 1024-byte buffer for their parameters. When writing forms for ISAPI, either use only the POST method, or design the ISA so that only the default function handles the form.

For example, some browsers sending a form via GET with an action of:

TestLet.DLL?Command

will truncate Command and send

TestLet.DLL?name=value

instead of the correct command,

TestLet.DLL?Command?name=value

By truncating Command, the browser removes the association to the ISA function needed to map the request. Unless the function Command is the default function, the form will not be handled correctly.

What do you want to know more about?

• Processing HTML Forms Using Internet Server Extension DLLs and Command Handlers

• Declaring a Command in a Parse Map

• Passing a String from the URL

• Naming Parameters with ON_PARSE_COMMAND_PARAMS

• Managing Required and Optional Parameters