Introduction to Data Management

Developing Applications With PATHMAKER
15873 Tandem Computers Incorporated 5-13
PATHMAKER provides all COBOL code needed for your server, except for the
Procedure Division and some of the entries in the Working-Storage Section of the Data
Division. For those two areas, PATHMAKER furnishes only framework or skeleton
code—you must either write the missing code yourself, or use the PATHMAKER
general-purpose database server for services that perform standard database functions
and require no custom code. If you supply your own code, PATHMAKER merges
that code into your application from the files you specified earlier.
Through additional screens, you describe what database elements your requester will
send to the service and what elements the service will transmit back to the requester.
These elements move between requester and service within interprocess
communication messages; PATHMAKER automatically formats these messages for
transmittal and then generates the COBOL code for the messages.
As part of the service creation step, you also specify the names of any files and record
definitions referred to by the service. This step relates the data records to the file
names used for them in the COBOL service code.
Defining the Server
Once you have specified the required services, you must package them into an
integrated server program through additional PATHMAKER screens. Here, you
specify the files that will contain the source code and the compiled code (generated by
PATHMAKER) for the server. Then, you identify the services that are to be part of the
new server.
From the information supplied on the service and server definition screens,
PATHMAKER generates and compiles the servers for your application.
Completing the Requester
When you have generated the server, you are ready to complete the final steps in
producing your requester. These steps include specifying parameters to be passed
between your requester and server, writing a description of the requester that the end
user can display as help text, and then actually generating the requester. During
requester generation, PATHMAKER produces the SCREEN COBOL code for the
requester and compiles that code for you.
Notice that you need not write any SCREEN COBOL code yourself; PATHMAKER
generates a complete and usable requester program from the function key
assignments and other information that you supplied on the PATHMAKER screens.
However, you can augment this standard logic with your own specialized code
supplied from SCREEN COBOL copy libraries. This custom code can be called into
execution at predefined points during processing of user input.