/**
* Shared logic that works out whether a particular subscriber receives a
* discussion or not.
* @param forum $forum Forum
* @param forum_discussion $discussion Discussion
* @param object $subscriber Subscriber
*/
function subscriber_receives_discussion($forum, $discussion, $subscriber)
{
// Did they subscribe specifically to this discussion?
$explicitsubscribed = array_key_exists($discussion->get_id(), $subscriber->discussionids);
// Did they subscribe to the group this discussion belongs to
$explicitsubscribedtogroup = in_array($discussion->get_group_id(), $subscriber->groupids);
$groupid = $discussion->get_group_id();
$visiblegroups = $forum->get_group_mode() == VISIBLEGROUPS;
// Conditions for each subscriber to get this discussion
$result = ($subscriber->wholeforum || $explicitsubscribed || $explicitsubscribedtogroup) && (!$groupid || $subscriber->accessallgroups || $visiblegroups || array_key_exists($groupid, $subscriber->groups)) && $forum->get_type()->can_view_discussion($discussion, $subscriber->id);
return $result;
}