A Rogue Wave® Views Studio message contains information that describes an event that took place. A message collects subscriptions. A subscription is an action that is performed whenever a message is sent. Messages are never created by the user, but are accessed through the editor using their names.

A subscription is a subclass of the IlvStSubscription class, which is declared in the file <ivstudio/message.h>. It is associated with a receiver and has a doIt virtual member function. For example, when a panel wants to react to the ObjectSelected message that is generated each time the object selection changes in the current buffer, it subscribes to this message using a subscription instance. This can be done in the panel constructor by calling the member function subscribe on the message instance. The message instance is given by the editor through its name. Then, whenever the message ObjectSelected is sent, the doIt member function of this subscription is invoked.