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

58 Chapter3
INTRODUCTION TO FORMS DESIGN
GETTING STARTED WITH FORMSPEC
Creating an Application-Ready Buffer (ARB)
The purpose of the ARB is to allow you to transform screen data into application data and
back again by converting data types between screen and application, and by reordering the
fields.
Once you have created a form and saved it in the forms file, you can create an
application-ready buffer (ARB) for it if you choose. Not every form needs to have an ARB,
you can create ARB's for selected forms only. You can also create an ARB for a form at any
time after you have created the form itself, and you can delete an existing ARB and
generate a new one if you have made extensive changes to the associated form. Fields on
the form are mapped one-to-one to the ARB when you select GEN from the ARB Menu.
You can rearrange fields on the form using the Screen Design Menu without affecting the
ARB, and you can add and delete ARB fields without affecting the form by selecting RES
(Restructure) from the ARB Menu.
Before you can generate and ARB, you must define the Data Type Conversions you want to
take place between the form on the screen and the ARB. From the Globals Menu, you
access the Data Type Conversions menu and define the data conversion defaults. Screen
and application data types are listed under "Data Type" further on in this section.
Creation of an ARB is described in detail under "Using FORMSPEC to Create an ARB" in
this section.
At runtime, the ARB transforms the data as it appears on the screen into a format that the
application can use without further manipulation, and converts application data back into
a format suitable for display on the screen.
Year 2000 Functionality
VPLUS contains new functionality to address Year 2000 issues. The following sections
describe features related to Year 2000 functions.
FORMSPEC Enhancements
FORMSPEC Application Ready Buffer (ARB) processing has been enhanced with the addition
of a new ARB data type. This data type can be specified on the DTC Menu for Data Type
Conversions from Screen Type to Application Type. The new ARB Type is YYYYMD and is
defined as a 8-byte ASCII field containing a date value in YMD order with no separators.
Also the year component in the date value has 4 digits. Note that FORMSPEC will ensure a
length of 8 for the data type YYYYMD in the ARB. In essence, the value is of the form
YYYYMMDD (8 bytes) even though the Type designator on the DTC Menu has been
abbreviated to YYYYMD.
Processing Enhancements
Date processing in VPLUS has been enhanced to handle date values with 4-digit year
components. Specifically, the following additions have been made.
Date output will be formatted with 4-digit years if the target field is wide enough to receive
the date, and the user requests this action. Examples of such output include the SET
statement in FORMSPEC. The target field should be at least 10 characters in length to have
a 4-digit year output.