Controlling a tree-view with DISPLAY ARRAY

A DISPLAY ARRAY dialog needs to be used to control a tree-view.

After the program array has been filled, you must execute a DISPLAY ARRAY dialog.

The next code example implements a DISPLAY ARRAY binding the program array called tree_arr to the sr screen-array, attaching the dialog to the tree table defined in the form:

CALL fill_tree(tree_arr)
DISPLAY ARRAY tree_arr TO sr.* ATTRIBUTES(UNBUFFERED)
  BEFORE ROW
    DISPLAY "Current row is: ", DIALOG.getCurrentRow("sr")
END DISPLAY

It is not possible to use the DISPLAY ARRAY paged mode (ON FILL BUFFER) when the decoration is a tree view list. The dialog needs the complete set of open nodes with parent/child relation to handle the tree view display, with the paged mode only a given window of the dataset is known by the dialog. If you use a the paged mode in DISPLAY ARRAY with a tree view as decoration, the program will raise an error at runtime.

However, tree-views can be filled dynamically with ON EXPAND / ON COLLAPSE triggers.