Introduction to Pathmaker

Overview of Pathway
Introduction to Pathmaker and Pathway
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Requester Functions
A requester is an interactive program that displays and manages transaction data on
the end user’s terminal screen. In this capacity, a requester performs these functions:
Provides the data entry screens for the application terminal.
Accepts data entered at the terminal.
Performs preliminary input validation.
Builds a request message from the accepted data.
Passes the request message to the appropriate server program to perform specific
actions against the database, such as retrieving and updating data.
Receives and evaluates the reply message from the server and creates screen
displays for response to the end user.
Requesters are written in SCREEN COBOL, a high-level language similar to COBOL
and designed specifically to create Pathway requester programs. Once coded, the
requester is translated into pseudocode (using the SCOBOLX compiler) and is then
stored in a SCREEN COBOL library.
Server Functions
A server is a database management program, written in a programming language
such as COBOL85. In a Pathmaker application, a server is made up of one or more
services. In fact, a server is a package of services that are grouped together according
to certain aspects they have in common (such as processing time).
A server performs all message handling and provides a framework for one or more
services that contain the code to manipulate data, perform calculations, validate input,
and access the database.
Servers perform the following functions:
Read messages from requesters and route them to the appropriate services.
Relay the reply message created by a service back to the requester after the service
has completed its work.
Note The Pathmaker product generates servers in either COBOL85 or C.