About displaying and validating data
When PowerBuilder generates a basic DataWindow object, it uses the extended
attributes defined for the data and stored in the extended attribute system
tables.
For more information about the extended attribute
system tables, see Appendix A, “The Extended
Attribute System Tables”.
In the Database painter, you can create the extended attribute
definitions that specify a column’s display format, edit
style, and validation rules.
In the DataWindow painter, you can override these extended
attribute definitions for a column in a DataWindow object. These overrides
do not change the information stored with the column definition
in the extended attribute system tables.
Presenting the data
When you generate a new DataWindow object, PowerBuilder presents the
data according to the properties already defined for a column, such
as a column’s display format and edit style.
Display formats
Display formats embellish data values while still displaying
them as letters, numbers, and special characters. Using display
formats, for example, you can:
- Change
the color of numbers to display a negative value - Add parentheses and dashes to format a telephone
number - Add a dollar sign and period to indicate a currency
format
For information, see “Working with display
formats “.
Edit styles
Edit styles take precedence over display formats and specify
how column data is presented. For example, using edit styles, you
can:
- Display valid values
in a dropdown listbox - Indicate that a single value is selected by a checkbox
- Indicate which of a group of values is selected
with radio buttons
In the Database painter, an edit style enables users to change
data
in the database by means of an edit mechanism, such as a checkbox
or radio buttons.
In the DataWindow painter, an edit style is simply a way of presenting
data. You
can change data in a DataWindow object; you cannot change data in a report.
For more information, see “Working with edit styles “.
Validating data
When data is entered in the Database painter or in a DataWindow object, PowerBuilder evaluates
the data against validation rules defined for that column. If the
data is valid, PowerBuilder accepts the entry; otherwise, PowerBuilder displays
an error message and does not accept the entry.
For more information, see “Working with validation
rules “.