Nested folder tabs

When a FOLDER PAGE contains another FOLDER container, it defines a sub-folder.

When a user selects the tab of the parent folder page containing the sub-folder, it is possible to show a given sub-folder page, by calling the ui.Form.ensureFieldVisible() or ui.Form.ensureElementVisible() method, in the BEFORE INPUT, BEFORE DISPLAY or BEFORE CONSTRUCT of the sub-dialog controlling the parent folder page:

DIALOG ...
    -- Sub-dialog controlling the parent folder page
    INPUT BY NAME rec_customer.* ...
       BEFORE INPUT -- focus goes to a field of this sub-dialog/folder page
           -- Show the main page of the sub-folder with orders info
           CALL DIALOG.getForm().ensureFieldVisible("orders.order_num")
       ...
    END INPUT
    -- Sub-dialog controlling sub-folder main page
    INPUT BY NAME rec_orders.* ...
       ...

Note that the focus will stay in the current field of the parent folder page because this is not a NEXT FIELD.