Properties that control the appearance and behavior of a column with the DropDownDataWindow edit style.
Column controls
Describe and Modify argument:
"columnname.dddw.property { = value }"
Parameter |
Description |
---|---|
columnname |
The name of a column that has the DropDownDataWindow edit style. |
property |
A property for the DropDownDataWindow column. Properties and their settings are listed in the table below. |
value |
The value to be assigned to the property. For dddw properties, value cannot be a DataWindow expression. |
Property for dddw |
Value |
---|---|
AllowEdit |
Whether the user can type a value as well as choose from the DropDownDataWindow’s list. Values are:
Call GetChild after setting dddw.AllowEdit to get a valid reference to the column’s DropDownDataWindow. |
AutoHScroll |
Whether the DropDownDataWindow automatically scrolls horizontally when the user enters or deletes data. Values are:
|
AutoRetrieve |
Whether the DropDownDataWindow data is retrieved when the parent DataWindow data is retrieved. Values are:
|
Case |
The case of the text in the DropDownDataWindow. Values are:
Call GetChild after setting dddw.Case to get a valid reference to the column’s DropDownDataWindow. |
DataColumn |
A string whose value is the name of the data column in the associated DropDownDataWindow. Value is quoted. Call GetChild after setting dddw.DataColumn to get a valid reference to the column’s DropDownDataWindow. |
DisplayColumn |
A string whose value is the name of the display column in the associated DropDownDataWindow. Value is quoted. Call GetChild after setting dddw.DisplayColumn to get a valid reference to the column’s DropDownDataWindow. |
HScrollBar |
Whether a horizontal scroll bar displays in the DropDownDataWindow. Values are:
|
HSplitScroll |
Whether the horizontal scroll bar is split. The user can adjust the split position. Values are:
|
Limit |
An integer from 0 to 32767 specifying the maximum number of characters that can be entered in the DropDownDataWindow. Zero means unlimited. |
Lines |
An integer from 0 to 32767 specifying the number of lines (values) to display in the DropDownDataWindow. This property does not apply in Web pages because the browser controls how the DropDownDataWindow displays. |
Name |
A string whose value is the name of the DropDownDataWindow associated with the column. Call GetChild after setting dddw.Name to get a valid reference to the column’s DropDownDataWindow. |
NilIsNull |
Whether to set the data value of the DropDownDataWindow to null when the user leaves the edit box blank. Values are:
|
PercentWidth |
An integer specifying the width of the drop-down portion of the DropDownDataWindow as a percentage of the column’s width. For example, 300 sets the display width to three times the column width. Call GetChild after setting dddw.PercentWidth to get a valid reference to the column’s DropDownDataWindow. |
Required |
Whether the column is required. Values are:
|
ShowList |
Whether the ListBox portion of the DropDownDataWindow displays when the column has focus. A down arrow does not display at the right end of the DropDownDataWindow when dddw.ShowList is yes. Values are:
|
UseAsBorder |
Whether a down arrow displays at the right end of the DropDownDataWindow. Values are:
Note that if ShowList is set to Yes, the column ignores the UseAsBorder property and the arrow never displays. |
VScrollBar |
Whether a vertical scroll bar displays in the DropDownDataWindow for long lists. Values are:
|
When you set some of the dddw properties, as noted in the table, references to the DropDownDataWindow become invalid. Call GetChild again after changing these properties to obtain a valid reference.
To retrieve a DropDownDataWindow when the AutoRetrieve property is set to “false”, you can access the object data as follows:
DataWindowChild mgr_id
dw1.GetChild ("dept_head_id", mgr_id)
mgr_id.SetTransObject (SQLCA)
mgr_id.Retrieve ( )
You can also pass a retrieval argument for the retrieve on the child DataWindow object.
When a DropDownDataWindow is retrieved, its data is kept with its own Data Object. If you retrieve the DropDownDataWindow and then set the AutoRetrieve property on the parent to “false”, the data for the child is not cleared on a reset and re-retrieve of the parent.
To clear data from a DropDownDataWindow, you must call Reset on the child DataWindow object:
dw1.GetChild ("dept_head_id", mgr_id)
mgr_id.reset ( )
Select the control and set values in the Properties view, Edit tab, when Style Type is DropDownDW.
ls_data = dw1.Describe("emp_status.dddw.AllowEdit")
dw1.Modify("emp_status.dddw.Case='Any'")
dw1.Modify("emp_status.dddw.DataColumn='status_id'")
dw1.Modify("emp_status.dddw.Limit=30")
dw1.Modify("emp_status.dddw.Name='d_status'")
dw1.Modify("emp_status.dddw.PercentWidth=120")