GUIBaseContext :: doBeforeDataSet - Pre-event handler for fill line data
The handler is called before a line in a tree or list is going to be filled ( DEV_BeforeDataSet event). The handler is called for each item in the list, but also for static lines. The selected item is available in the current property handle ( property() ).
When updating items for a list of a combo-box, the function returns the property handle for the list rather than the property handle for the combo box data source.
The handler allows filtering items in a list. In order to filter items, selection must be set for the control ( setFilter( true ) ) in the open handler ( doAfterOpen() ). For accepting an item, the handler should return 0 . In order to reject items the function returns 1 . Static lines cannot be rejected. In order to determine, whether the current line is a static line or not, one may call the L ine::type() function.
The handler should return one of the following values:
- -1 (not handled) - the event handler will be removed from the handler list and is not called anymore.
- 1 (refuse) - Currently selected instance is rejected.
- 0 (ok) - Currently selected instance is accepted.
int8 cPersonTree :: DoBeforeDataSet ( ) {
Property &p = currentProperty();
return ( p.integer("age") < 18 ? 1 : 0);
}