UserModel::saveRoles PHP Method

    public function saveRoles($UserID, $RoleIDs, $RecordEvent)
    {
        if (is_string($RoleIDs) && !is_numeric($RoleIDs)) {
            // The $RoleIDs are a comma delimited list of role names.
            $RoleNames = array_map('trim', explode(',', $RoleIDs));
            $RoleIDs = $this->SQL->select('r.RoleID')->from('Role r')->whereIn('r.Name', $RoleNames)->get()->resultArray();
            $RoleIDs = array_column($RoleIDs, 'RoleID');
        }
        if (!is_array($RoleIDs)) {
            $RoleIDs = [$RoleIDs];
        }
        // Get the current roles.
        $OldRoleIDs = [];
        $OldRoleData = $this->SQL->select('ur.RoleID, r.Name')->from('UserRole ur')->join('Role r', 'r.RoleID = ur.RoleID', 'left')->where('ur.UserID', $UserID)->get()->resultArray();
        if ($OldRoleData !== false) {
            $OldRoleIDs = array_column($OldRoleData, 'RoleID');
        }
        // 1a) Figure out which roles to delete.
        $DeleteRoleIDs = [];
        foreach ($OldRoleData as $row) {
            // The role should be deleted if it is an orphan or the user has not been assigned the role.
            if ($row['Name'] === null || !in_array($row['RoleID'], $RoleIDs)) {
                $DeleteRoleIDs[] = $row['RoleID'];
            }
        }
        // 1b) Remove old role associations for this user.
        if (!empty($DeleteRoleIDs)) {
            $this->SQL->whereIn('RoleID', $DeleteRoleIDs)->delete('UserRole', ['UserID' => $UserID]);
        }
        // 2a) Figure out which roles to insert.
        $InsertRoleIDs = array_diff($RoleIDs, $OldRoleIDs);
        // 2b) Insert the new role associations for this user.
        foreach ($InsertRoleIDs as $InsertRoleID) {
            if (is_numeric($InsertRoleID)) {
                $this->SQL->insert('UserRole', ['UserID' => $UserID, 'RoleID' => $InsertRoleID]);
            }
        }
        $this->clearCache($UserID, ['roles', 'permissions']);
        if ($RecordEvent) {
            $User = $this->getID($UserID);
            $OldRoles = [];
            foreach ($DeleteRoleIDs as $deleteRoleID) {
                $role = RoleModel::roles($deleteRoleID);
                $OldRoles[] = val('Name', $role, t('Unknown') . ' (' . $deleteRoleID . ')');
            }
            $NewRoles = [];
            foreach ($InsertRoleIDs as $insertRoleID) {
                $role = RoleModel::roles($insertRoleID);
                $NewRoles[] = val('Name', $role, t('Unknown') . ' (' . $insertRoleID . ')');
            }
            $RemovedRoles = array_diff($OldRoles, $NewRoles);
            $NewRoles = array_diff($NewRoles, $OldRoles);
            foreach ($RemovedRoles as $RoleName) {
                Logger::event('role_remove', Logger::INFO, "{username} removed {toUsername} from the {role} role.", ['touserid' => $User->UserID, 'toUsername' => $User->Name, 'role' => $RoleName]);
            }
            foreach ($NewRoles as $RoleName) {
                Logger::event('role_add', Logger::INFO, "{username} added {toUsername} to the {role} role.", ['touserid' => $User->UserID, 'toUsername' => $User->Name, 'role' => $RoleName]);
            }
        }
    }