groupable-enabled is set to
false, grouping is disabled.
groupable-show-footer is enabled, the group footer rows will remain visible when the corresponding group is collapsed.
groupable-sort-compare has the same signature as the
compare function that is accepted by
Array.sort. For more information, refer to the article on sorting items of the groups.
The sort order of the groups according to the group field.
The supported values are:
The text which is displayed in the grouping drop area.