As for GUI components, callbacks are specified as Tcl commands. For a download operation usually empty at beginning and filled with data during download. For an upload operation usually filled with document metainformation before upload. Wafe interface allows creation of an anchor, association with an URL and retrieval of values of attributes. Has many parameters, which configure the networking operation in great detail.
Wafe interface allows creation of request and modification of attributes.
The request is started and the two handles are passed. The specified handler dumps downloaded data to a temporary file and executes the xedit editor afterwards. In this case, incremental download is performed but not used. With w3AddConverter an incremental presenter is registered for a specific content-type. Within the handler procedure, percent-code substitution is used to retrieve the request handle and the filename.