+
+ // isSubgroupValid determines if a subgroup is valid for user.
+ // A subgroup is valid if:
+ // - user can manage_subgroups;
+ // - subgroup is either a direct child of user group, or "on the path"
+ // to it (grand-child, etc.).
+ function isSubgroupValid($subgroup_id) {
+ if (!$this->can('manage_subgroups')) return false; // User cannot manage subgroups.
+
+ $current_group_id = $subgroup_id;
+ while ($parent_group_id = ttGroupHelper::getParentGroup($current_group_id)) {
+ if ($parent_group_id == $this->group_id) {
+ return true; // Found it.
+ }
+ $current_group_id = $parent_group_id;
+ }
+ return false;
+ }
+
+ // getMaxRankForGroup determines effective user rank for a user in a given group.
+ // For home group it is the existing user rank (as per role) minus 1.
+ // For subgroups, if user can "manage_subgroups", it is MAX_RANK.
+ function getMaxRankForGroup($group_id) {
+
+ $max_rank = 0; // Start safely.
+ if ($this->group_id == $group_id) {
+ $max_rank = $this->rank - 1;
+ return $max_rank;
+ }
+
+ if ($this->isSubgroupValid($group_id))
+ $max_rank = MAX_RANK;
+
+ return $max_rank;
+ }