Search (SEEK)

Search operator tries to make the specified object collection current for the specified form object group. The objects from the specified object collection shall be called seek objects.

Seek direction

If the object group for which the search is performed contains objects other than search objects, for these objects (which we will call additional) the collection of objects that will be selected as current is determined by special options:

• FIRST - the first matching collection according to the specified order will be selected.
• LAST - the last matching collection according to the specified order will be selected.

If the required object collection is not found for the seek objects, the current object collection will be the closest to the desired one. The direction in which this closest object collection will be selected is also determined by the above options:

• FIRST - the next closest collection according to the specified order will be selected.
• LAST - the previous closest collection according to the specified order will be selected.

Setting NULL Values

Also, this operator allows resetting all objects of the specified group to NULL. In this case, the seek direction is not applicable/not specified.

Language

To declare an action that implements an object change, use the SEEK operator.

Examples

number = DATA INTEGER (Order);
FORM orders
    OBJECTS o = Order
    PROPERTIES(o) READONLY number, currency, customer
;
newOrder  {
    NEW new = Order {
        number(new) <- (GROUP MAX number(Order o)) (+) 1;
        SEEK orders.o = new;
    }
}
seekFirst  { SEEK FIRST orders.o; }
seekLast  { SEEK LAST orders.o; }

EXTEND FORM orders
    PROPERTIES(o) newOrder, seekFirst, seekLast
;