Introduction to Pathmaker

Types of Pathmaker Applications
Pathmaker Applications
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Transaction (TRNS) Requester. A transaction (TRNS) requester displays a screen similar
in appearance to the screen for a DB requester. The important difference is that an end
user can only invoke a custom service by using a transaction requester.
Note Transaction requesters cannot use the standard services.
Custom Service. A custom service can perform database access, data manipulation,
editing, and calculations. The Pathmaker product provides a framework for each
custom service. Application developers must supply the COBOL85 or C code that
does the work. For custom services that access data in NonStop SQL tables, the
Pathmaker product can be used to generate some SQL database access statements.
COBOL85 Custom Service. Using special EDIT files, application developers supply the
COBOL85 code for each service for the:
Working-Storage Section
Extended-Storage Section
Procedure Division
Application developers use the Pathmaker product to package custom COBOL85
services into custom COBOL85 servers and then generate and compile those servers.
(When a Pathmaker server is generated, each service in it is included as a separate
COBOL85 subprogram.)
When a COBOL85 server generated by the Pathmaker product is run, it receives a
message from a requester, invokes the appropriate subprogram (that is, service) to
process the request, and returns a reply to the requester. To make this series of actions
work, each custom COBOL85 server contains the following components:
File description entries (FDs)
Overall program control logic
Code to handle messages in the $RECEIVE file
Error logic
File opens and closes (if applicable)
Host variables (for NonStop SQL tables)
C Custom Service. A Pathmaker service written in C consists of:
A custom source file
A generated source file
An object file
A custom source file is created by the Pathmaker product when the application
developer adds a C service. A custom source file initially contains empty definitions.
Application developers add data declarations and functions to this file to perform the
service’s business task.