LABEL item type
Defines a simple text area to display a read-only value.
LABEL item basics
The LABEL
form item defines a read-only text area.
Defining a LABEL
A LABEL
form item can be defined as a form field image or as a static label.
Use a form field label when the text changes often during program execution (for example, to
display text from the database). Use a static label if the text remains the same during program
execution.
Front-ends support different presentation and behavior options, which can be controlled by
a STYLE
attribute. For more
details, see Style attributes common to all elements and Label style attributes.
Form field LABEL item
Use a form field label item to display values that change often during program execution, for example if the text is stored in the database.
The label text is defined by the value of the field.
The value can be changed by the program using the DISPLAY BY NAME / DISPLAY TO
instruction, or just by changing the value of the program variable bound to the label field when
using the UNBUFFERED
mode in an interactive instruction.
When defining the LABEL
item in the form, use a field name to identify the
element in programs:
LABEL f001 = cars.description;
Static LABEL item
Use a static label item to display text that does not change during program execution.
This kind of item is not affected by instructions such as CLEAR FORM
or the
DISPLAY TO
instruction.
LABEL lab1: label1, TEXT="Name:";
LABEL ...
TEXT = %"label.customer.name";
Static labels display only character text values, and therefore do not follow any justification rule as form field labels.
Multi-line text in LABELs
\n
line-feed characters:LABEL lab1: label1,
TEXT="First line.\nSecond line.";
Where to use a LABEL
A LABEL
form item can be defined with an item tag and a LABEL item definition in a GRID
, SCROLLGRID
and TABLE
/TREE
.
Defining the widget size
The size of a LABEL
widget can be controlled by using the SIZEPOLICY
attribute.
By default (SIZEPOLICY=INITIAL
), labels adapt their width to the initial text
displayed by the element.
With static labels, the initial text is usually defined in the form file, or with a localized string, and the size does not need to adapt once the label is displayed.
When using form field
labels, the same default rule applies. However, if the initial text displayed in the form
field is NULL
or smaller than other texts that will be displayed, the size of the
label element will not adapt after the initial text is displayed; the label stays at the size of the
initial displayed text.
When using a form field label, make sure that the size of the label will be
large enough to display all possible values. To control the label size, use the
SIZEPOLICY=DYNAMIC
attribute, or use SIZEPOLICY=FIXED
and define
the form item with a sufficient size in the LAYOUT
section.