Fax Client Object Hierarchy

Most of the Component Object Model (COM) interfaces in the Fax Service Client API are hierarchical in nature. For example, the client application must call the IFaxServer::Connect method (or the Connect Microsoft Visual Basic method of the FaxServer object) to establish a connection with a fax server before accessing other interfaces that begin with IFax, or other fax client objects. (The FaxTiff object is an exception: a fax server connection is not required to access a FaxTiff object.)

After a client application establishes a connection through remote procedure call (RPC) to an active fax server, the application can call other interface methods. This is because the active FaxServer object "knows" the fax server to which it is connected. For example, the application can call one of the following methods.

• The IFaxServer::GetJobs method (or the GetJobs Visual Basic method of the FaxServer object) to create a FaxJobs object and retrieve a list of the fax jobs associated with the connected fax server.
• The IFaxServer::GetPorts method (or the GetPorts Visual Basic method of the FaxServer object) to create a FaxPorts object and retrieve a list of ports associated with the connected fax server.
• The IFaxServer::CreateDocument method (or the CreateDocument Visual Basic method of the FaxServer object) to create a FaxDoc object and send a fax transmission.

A client application should not call the CoCreateInstance function to create these objects or objects derived from them. For more information about creating fax client objects, see the steps that are listed with each interface topic, the Fax Service Client API Visual Basic Reference, and the hierarchical diagram in The Fax Client Object Model.