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.
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:
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Change the color of numbers to display a negative value
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Add parentheses and dashes to format a telephone number
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Add a dollar sign and period to indicate a currency format
For information, see About display formats.
Edit styles
Edit styles usually take precedence over display formats and specify how column data is presented. For example, using edit styles, you can:
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Display valid values in a drop-down list
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Indicate that a single value is selected by a check box
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Indicate which of a group of values is selected with radio buttons
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Edit styles affect not only the way data displays, they also affect how the user interacts with the data at runtime.
For more information, see About edit styles.
About display format masks and EditMask masks
The differences between display format masks and EditMask masks can be confusing. A display format mask determines the appearance of the column when the focus is off the column, or when the DataWindow object is in print preview mode. When you apply an EditMask edit style, the mask you use determines the appearance of the column when focus is on the column.
If you want data to display differently depending on whether the focus is on or off the column, specify an edit mask (on the Edit property page for the column) as well as a display format (on the Format property page for the column), then check the Use Format check box on the Format property page. The Use Format check box displays only when an edit mask has been specified.
If you want the data to display in the same way whether focus is on or off the column and you have defined an edit mask, you do not need to define a display format. The edit mask is used for display if the Use Format box is not checked (the default).
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 About validation rules.
