HP Data Entry and Forms Management System (VPLUS) Reference Manual (32209-90024)

32 Chapter1
VPLUS Overview
Product Overview
error enhancements and the placement of the error/status line on the form. You can change
these default characteristics using the Globals Menu.
Application-Ready Buffer
An application-ready buffer (ARB) is a buffer passed between the application and the
run-time intrinsics for data collection and display. It performs the following functions:
• Holds data as the application will use it, which may differ from how it appears on the
screen.
• Synchronizes with other application sources, such as the program code and databases.
• Facilitates maintenance in that the user can rearrange fields on the screen without
modifying the application program. Conversely, changes in the application program
that affect the ARB do not necessarily require changes in the screen.
• Supports an extended range of data types, including floating-point decimal and
COBOL-packed and zoned decimal.
• Simplifies coding, because the field-by-field transformation is specified in the forms file
rather than by using a series of transformation intrinsics in the application program.
The ARB presents data as the application expects to use it, such as to update a database,
whereas the screen receives and displays data in the format that the user understands.
This distinction between screen data and application-ready data facilitates maintenance.
Refer to Chapter 3 for information about creating an ARB.
Program Interface Intrinsics
All terminal-oriented applications can use a library of high-level intrinsics. Any of the
supported programming languages listed in appendix A can call these intrinsics. Appendix
A also contains listings of sample applications that use the intrinsics.
The program interface provides intrinsics for the following:
Terminal Interface These intrinsics open and close a terminal file, load and
unload forms (if the terminal has local forms storage),
display a form and data to the terminal, and read data
entered in fields of the displayed form.
Forms File Interface These intrinsics open and close a forms file, get the next
form in sequence from the forms file, and print the current
form, with its contents, on the line printer.
Data Manipulation These intrinsics initialize a form to its initial values,
perform any user-defined edits, and performany final form
processing.
Access to Data These intrinsics move data between the application
program and VPLUS work areas. The data can be moved
one field at a time or as a single buffer for the entire form.
Data can be moved as character strings, or it can be
transformed to and from internal representations most