TRANSFER Programming Manual

Examples of Clients
TRANSFER Application Components
40970 Tandem Computers Incorporated 2–3
Clients Clients are requester programs that provide the interface between correspondents and
the TRANSFER delivery system. They allow correspondents to communicate and
interact with the TRANSFER delivery system. A client, for example, enables a
correspondent to create new items, assemble them into packages, send these packages,
retrieve incoming packages, and request various administrative services. For every
TRANSFER application, you must code one or more clients.
A client typically performs the following functions:
Establishes and terminates communication with the TRANSFER delivery system
Manages the terminal interface on the basis of the screens you design and the code
you write to accept and display data on those screens
Composes items and packages at the depot
Assigns delivery parameters, such as package priority and delivery timeframe,
and sends packages for delivery
Takes certain actions based upon receipt of packages, such as presenting a
message to a user at a terminal or starting another transaction
Detects and reacts to certain error conditions
In terms of the PATHWAY requester-server model, clients are those requesters that
make requests of servers furnished as part of the TRANSFER delivery system.
A client can represent any number of correspondents.
Examples of Clients Examples of clients in TRANSFER applications include:
SCREEN COBOL programs operating under a PATHWAY terminal control
process (TCP); the SCREEN COBOL programs do one or more of the following:
Represent each operator as a correspondent
Represent each terminal as a correspondent
Represent all terminals and operators as a single correspondent
Represent other servers or devices handled by those servers as
correspondents
A GUARDIAN 90 process that makes requests of TRANSFER servers
on behalf of correspondents