Selection (SELECT)

The selection operators create properties that report the user's row and column selection in an object group:

• the property of an object collection returns TRUE if that collection is currently selected (checked) by the user in the group, and NULL otherwise;
• the property of the group as a whole returns TRUE if the user selected rows in the group, and NULL otherwise;
• the property of a column returns TRUE if that column is currently selected by the user, and NULL otherwise.

As long as the user has not selected any row, the property of an object collection returns TRUE for the current row of the object group; once there is a selection, it returns TRUE for the selected rows that pass all the form's filter conditions. The selected rows are kept as a range in the current order of the object group, so changing the order recomputes the set of selected rows. The column the current cell belongs to counts as selected.

Language

To declare these properties, use the SELECT, SELECT ACTIVE, and SELECT PROPERTY operators.

Examples

CLASS Store;
name = DATA STRING[100] (Store);

FORM stores
    OBJECTS s = Store
    PROPERTIES(s) name
;
selectedCount 'Number of selected stores' () = GROUP SUM 1 IF [ SELECT stores.s](Store s);
selectActive 'The selection is set' () = [ SELECT ACTIVE stores.s]();
nameSelected 'Name property is selected' () = [ SELECT PROPERTY stores.name(s)]();