Syntax for nested objects in DataWindow property expressions in PowerBuilder – PB Docs 126

Syntax for nested objects in DataWindow property expressions in PowerBuilder

Argument	Description
dwcontrol	The name of the DataWindow control or child DataWindow in which you want to get or set properties.
Object	The Object keyword indicates that subsequent elements refer to the DataWindow object within dwcontrol.
nestedcontrolname	The name of a DropDownDataWindow column, nested report, or OLE Object control within the DataWindow object in dwcontrol. About nested reports A nested report can be one of a group of reports in the Composite presentation style or a nested report included in a base report, which is associated with a specific row.
row	When nestedcontrolname is a nested report in a base report, the number of the row the report is associated with If the report is in a band other than the detail band, it is still associated with a row (see Usage below).
dwcontrolname	The name of a control within the nested DataWindow object. Possible values are DataWindow (for properties that apply to the whole DataWindow) or the name of a Button, Column, Computed field, Graph, GroupBox, Line, Oval, Picture, Rectangle, RoundRectangle, Report, TableBlob, or Text control. If dwcontrolname is a column with the DropDownDataWindow style, a Report control, or an OLE Object control, you can specify an additional Object keyword and dwcontrolname to refer to properties of controls within the nested DataWindow object. You can specify Object.dwcontrolname as many times as needed to refer to a control in a deeply nested DataWindow object.
property	A property that applies to dwcontrolname. If the property requires additional qualifying properties, list the additional properties, separating them with a dot. For lists of applicable properties, see the Property tables in Chapter 38, “DataWindow Object Properties”.
value	A string whose value is to be assigned to the property For more information, see “Basic syntax for DataWindow property expressions in PowerBuilder”.

For more information about the expression’s
datatype, see “Datatypes of DataWindow
property expressions in PowerBuilder”.

The following table lists the band and the row that is associated
with the report:

If the report is in this band	This row is associated with the report
detail	The specified row.
header	The first row on the page. On screen, this is the first row visible in the DataWindow body.
footer	The last row on the page. On screen, this is the last row visible in the DataWindow body.
header.n (group header)	The first row of the group (where n is the group number).
trailer.n (group trailer)	The last row of the group (where n is the group number).
summary	The last row in the report.

Example 2 In a Composite DataWindow,
one of the reports rpt_1 has a graph gr_1. This
example turns on grid lines for the category axis of that graph.
The example sets an instance variable to a default value of “not
found.” If the expression fails and triggers the Error
event, the ExceptionSubstituteReturnValue! action causes the text “not
found” to be returned so that the second assignment succeeds:

The script for the Error event includes these lines:

Example 3 Suppose that a DataWindow
called dw_emp is a base report with employee information.
The detail band includes a nested report of salary history called
rpt_salary. This means there is a separate report with
its own properties in each row.

The script checks whether the employee belongs to management
(the value in the rank column in the base report is M). If so, the
script assigns a DataWindow expression to the Color property of
the salary column in the rpt_salary nested report. The
expression highlights salaries that are over $60,000 in
red.

Another statement sets the salary column’s Mode property
so the color change will be visible:

Example 4 In this example there
is a graph in the summary band of a base report called dw_emp.
The graph is a nested report called rpt_graph_salaries. Although
the graph is not related to a particular row, you still need to
provide the row number associated with the summary band when you
refer to its properties. This statement turns on autoscaling for
the values axis:

Example 5 If a column has a
DropDownDataWindow edit style, there are properties that affect
the column’s appearance. Using nested object syntax, you can
also change properties of the child DataWindow for the column. In
this example, the DataWindow dw_gift allows a clerk at
a nonprofit organization to record donations. The clerk can pick
a standard donation amount from a drop-down DataWindow.

This example makes the drop-down DataWindow column called
amount a required value and changes the display format for the dollars
column in the child DataWindow:

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