Primitive input (INPUT)

The primitive input operator creates an action that requests the client to input a value of a builtin class. The user can cancel the input, for example by pressing the Esc key on the keyboard.

As with other value input operators, this operator allows to:

• specify initial object values
• specify main and alternative actions. The first is called if the input was successfully completed, the second if not (i.e. if the input was canceled).
• change a specified property

This operator can only be used in property change event handlers on a form.

Language

The syntax of the primitive input operator is described by the INPUT operator.

Examples

changeCustomer (Order o)  {
    INPUT s = STRING[100] DO {
        customer(o) <- s;
        IF s THEN
            MESSAGE 'Customer changed to ' + s;
        ELSE
            MESSAGE 'Customer dropped';
    }
}

FORM order
    OBJECTS o = Order
    PROPERTIES(o) customer ON CHANGE changeCustomer(o)
;

testFile  {
    INPUT f = FILE DO { // requesting a dialog to select a file
        open(f); // opening the selected file
    }
}