Getting progress information asynchronously

An application can ask to be informed when a change in the state of a dial-up connection occurs.

The request that the application makes is an asynchronous request, i.e. it is one which completes at some later time.

To do this, an application calls the ProgressNotification() member function of RNif (in practice, the class involved is one derived from RNif) prior to v7.0S or RConnection in v7.0S onwards.

The function takes a TRequestStatus object, as is usual with asynchronous requests, and a package buffer, a TNifProgressBuf, which packages a TNifProgress object.

When the request completes, the iStage data member of the TNifProgress object contains the information defining the current state of the connection.

An outstanding request for notification can be cancelled using the CancelProgressNotification() member function of RNif or RConnection.

In practice, an application would package this functionality as an active object.