Using VPLUS: An Introduction to Forms Design (32209-90004)

6-1
Chapter 6 Using Safe Fields and Understanding Phases
Values entered on one form of a forms file can be transferred to another
form through the use of save fields, which are fields in the forms file
that are independent of any particular form. As such, they can be used
to hold values for transfer between forms. Save fields are defined on
the Save Field Menu. This section will discuss the definition and use of
Save Fields.
Processing statements can be executed before, after, or while the form
is
displayed. These different times to execute processing statements are
called phases and are defined as initialization (before), field edits
(while), and finish (after) phases. Phases, in general, are discussed
in
this section, and use of the initialization phase is illustrated.
In the exercise in this section, you use three save fields to transfer
the order number, total net price, and the customer name from the ORDER
form to the TOTALS form. In addition, through the use of phases, you
make the order number completely automatic by incrementing its value
each
time the ORDER form is newly displayed. Later, when the forms file is
compiled with these various changes, you use ENTRY to show how values are
incremented, transferred between forms, and saved even when ENTRY is
terminated and restarted. The features covered in this section are:
Using FORMSPEC: Using ENTRY:
* Add and Modify Save Fields. * Enter data for calculated
values.
* Use Save Fields to assign values to fields* Review calculated values.
* Discuss phases in form processing. * Terminate and resume data
entry.
* Use the initialization phase. * Modify data transferred
between forms.
* Use Save Fields to pass values between forms.