function changerole_validate(Pieform $form, $values)
{
global $user, $group;
if (!group_can_change_role($group->id, $user->id, $values['role'])) {
$form->set_error('role', get_string('usercannotchangetothisrole', 'group'));
}
}
/**
* Changes a user role in a group, if this is allowed.
*
* @param int $groupid The ID of the group
* @param int $userid The ID of the user whose role needs changing
* @param string $role The role the user wishes to switch to
* @throws AccessDeniedException If the specified role change is not allowed.
* Check with group_can_change_role first if you
* need to.
*/
function group_change_role($groupid, $userid, $role)
{
// group_can_change_role checks whether the group and user parameters are valid
if (!group_can_change_role($groupid, $userid, $role)) {
throw new AccessDeniedException(get_string('usercannotchangetothisrole', 'group'));
}
set_field('group_member', 'role', $role, 'group', $groupid, 'member', $userid);
}