function scorm_seq_flow($activity, $direction, $seq, $childrenflag, $userid)
{
// TODO: $PREVDIRECTION NOT DEFINED YET.
$prevdirection = null;
$seq = scorm_seq_flow_tree_traversal($activity, $direction, $childrenflag, $prevdirection, $seq, $userid);
if ($seq->nextactivity == null) {
$seq->nextactivity = $activity;
$seq->deliverable = false;
return $seq;
} else {
$activity = $seq->nextactivity;
$seq = scorm_seq_flow_activity_traversal($activity, $userid, $direction, $childrenflag, null, $seq, $userid);
return $seq;
}
}
function scorm_seq_flow_tree_traversal($activity, $direction, $childrenflag, $prevdirection, $seq, $userid)
{
$revdirection = false;
$parent = scorm_get_parent($activity);
$children = scorm_get_available_children($parent);
$siz = sizeof($children);
if ($prevdirection != null && $prevdirection == 'backward' && $children[$siz - 1]->id == $activity->id) {
$direction = 'backward';
$children[0] = $activity;
$revdirection = true;
}
if ($direction = 'forward') {
$ancestors = scorm_get_ancestors($activity);
$ancestorsroot = array_reverse($ancestors);
$preorder = scorm_get_preorder($ancestorsroot);
$siz = sizeof($preorder);
if ($activity->id == $preorder[$siz - 1]->id || $activity->parent == '/' && !$childrenflag) {
scorm_seq_terminate_descent($ancestorsroot, $userid);
$seq->endsession = true;
$seq->nextactivity = null;
return $seq;
}
if (scorm_is_leaf($activity) || !$childrenflag) {
if ($children[$siz - 1]->id == $activity->id) {
$seq = scorm_seq_flow_tree_traversal($parent, $direction, false, null, $seq, $userid);
// I think it's not necessary to do a return in here
} else {
$parent = scorm_get_parent($activity);
$children = scorm_get_available_children($parent);
$seq->traversaldir = $direction;
$sib = scorm_get_siblings($activity);
$pos = array_search($sib, $activity);
if ($pos !== false) {
if ($pos != sizeof($sib)) {
$seq->nextactivity = $sib[$pos + 1];
return $seq;
} else {
$ch = scorm_get_children($sib[0]);
$seq->nextactivity = $ch[0];
return $seq;
}
}
}
} else {
if (!empty($children)) {
$seq->traversaldir = $direction;
$seq->nextactivity = $children[0];
return $seq;
} else {
$seq->traversaldir = null;
$seq->nextactivity = $children[0];
$seq->exception = 'SB.2.1-2';
return $seq;
}
}
}
if ($direction = 'backward') {
if ($activity->parent == '/') {
$seq->traversaldir = null;
$seq->nextactivity = null;
$seq->exception = 'SB.2.1-3';
return $seq;
}
if (scorm_is_leaf($activity) || !$childrenflag) {
if (!$revdirection) {
if (isset($parent->forwardonly) && $parent->forwardonly == true) {
$seq->traversaldir = null;
$seq->nextactivity = null;
$seq->exception = 'SB.2.1-4';
return $seq;
}
}
if ($children[0]->id == $activity->id) {
$seq = scorm_seq_flow_tree_traversal($parent, 'backward', false, null, $seq);
return $seq;
} else {
$ancestors = scorm_get_ancestors($activity);
$ancestorsroot = array_reverse($ancestors);
$preorder = scorm_get_preorder($ancestorsroot);
$pos = array_search($preorder, $children[$siz]);
$preord = array_slice($preorder, 0, $pos - 1);
$revpreorder = array_reverse($preord);
$position = array_search($revpreorder, $activity);
$seq->nextactivity = $revpreorder[$pos + 1];
$seq->traversaldir = $direction;
return $seq;
}
} else {
if (!empty($children)) {
$activity = scorm_get_sco($activity->id);
if (isset($parent->flow) && $parent->flow == true) {
$children = scorm_get_children($activity);
$seq->traversaldir = 'forward';
$seq->nextactivity = $children[0];
return $seq;
} else {
$children = scorm_get_children($activity);
$seq->traversaldir = 'backward';
$seq->nextactivity = $children[sizeof($children) - 1];
return $seq;
}
} else {
$seq->traversaldir = null;
$seq->nextactivity = null;
$seq->exception = 'SB.2.1-2';
return $seq;
}
}
}
}
