Filtering an object interface definition to determine services needed

Abstract

A distributed object application builder apparatus filters an object definition to determine both information needed (plugs) and provided (sockets) by an object. Each part (a run-time instance of an object) in the builder has plugs and sockets interconnected to other parts to define a distributed object application program. At run time, actual instances of objects are substituted for the parts. A method of determining the plugs of an identified part retrieves the interface (object definition) corresponding to the part. Once retrieved, the plugs of the part are identified by determining the object-valued attributes of the retrieved interface, by determining the operations from the retrieved interface that require one object-valued argument, and by retrieving the factory argument list from the factory method for the object. These attributes and arguments constitute the plugs of the part. Sockets of a part are determined similarly. The plugs of a part are determined based upon their matching with a previously chosen socket. Similarly, if a plug is chosen first from a part, this chosen plug is matched with a socket of another part. A distributed object application program is constructed by choosing a first part, filtering its interface to determine its plugs and sockets, and then choosing and filtering the interface of a second part. Once plugs and sockets have been determined, they are connected to at least partially define a distributed object application program. The filtering takes place within a visual application builder using a graphical user interface to select and connect parts.