Built-in sort and tree-views

By default, the built-in sort is enabled in a TREE container; when the end user clicks on column headers, the runtime system sorts the visual representation of the program array. Tree nodes are ordered by levels; the children nodes are ordered inside a given parent node.

This is a powerful built-in feature. However, in some cases, the tree structure must be static (i.e. the order of the nodes must not change) and you don't want the end user to sort the rows. To prevent the built-in sort, use the UNSORTABLECOLUMNS attribute for the TREE container definition:

LAYOUT
...
END
ATTRIBUTES
TREE tv: mytree, UNSORTABLECOLUMNS, ...
...