function scorm_get_preorder(&$preorder = array(), $sco = null)
{
if ($sco != null) {
array_push($preorder, $sco);
if ($children = scorm_get_children($sco)) {
foreach ($children as $child) {
scorm_get_preorder($preorder, $child);
}
}
}
return $preorder;
}
function scorm_get_preorder($preorder = array(), $sco)
{
if ($sco != null) {
array_push($preorder, $sco);
$children = scorm_get_children($sco);
foreach ($children as $child) {
scorm_get_preorder($sco);
}
} else {
return $preorder;
}
}
function scorm_seq_flow_tree_traversal($activity, $direction, $childrenflag, $prevdirection, $seq, $userid, $skip = false)
{
$revdirection = false;
$parent = scorm_get_parent($activity);
if (!empty($parent)) {
$children = scorm_get_available_children($parent);
} else {
$children = array();
}
$childrensize = count($children);
if ($prevdirection != null && $prevdirection == 'backward' && $children[$childrensize - 1]->id == $activity->id) {
$direction = 'backward';
$activity = $children[0];
$revdirection = true;
}
if ($direction == 'forward') {
$ancestors = scorm_get_ancestors($activity);
$ancestorsroot = array_reverse($ancestors);
$preorder = array();
$preorder = scorm_get_preorder($preorder, $ancestorsroot[0]);
$preordersize = count($preorder);
if ($activity->id == $preorder[$preordersize - 1]->id || $activity->parent == '/' && !$childrenflag) {
// scorm_seq_terminate_descent($ancestorsroot, $userid); TODO: undefined
$seq->endsession = true;
$seq->nextactivity = null;
return $seq;
}
if (scorm_is_leaf($activity) || !$childrenflag) {
if ($children[$childrensize - 1]->id == $activity->id) {
$seq = scorm_seq_flow_tree_traversal($parent, $direction, false, null, $seq, $userid);
if ($seq->nextactivity->launch == null) {
$seq = scorm_seq_flow_tree_traversal($seq->nextactivity, $direction, true, null, $seq, $userid);
}
return $seq;
} else {
$position = 0;
foreach ($children as $sco) {
if ($sco->id == $activity->id) {
break;
}
$position++;
}
if ($position != $childrensize - 1) {
$seq->nextactivity = $children[$position + 1];
$seq->traversaldir = $direction;
return $seq;
} else {
$siblings = scorm_get_siblings($activity);
$children = scorm_get_children($siblings[0]);
$seq->nextactivity = $children[0];
return $seq;
}
}
} else {
$children = scorm_get_available_children($activity);
if (!empty($children)) {
$seq->traversaldir = $direction;
$seq->nextactivity = $children[0];
return $seq;
} else {
$seq->traversaldir = null;
$seq->nextactivity = null;
$seq->exception = 'SB.2.1-2';
return $seq;
}
}
} else {
if ($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 && !$skip)) {
$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, $userid);
return $seq;
} else {
$ancestors = scorm_get_ancestors($activity);
$ancestorsroot = array_reverse($ancestors);
$preorder = array();
$preorder = scorm_get_preorder($preorder, $ancestorsroot[0]);
$position = 0;
foreach ($preorder as $sco) {
if ($sco->id == $activity->id) {
break;
}
$position++;
}
if (isset($preorder[$position])) {
$seq->nextactivity = $preorder[$position - 1];
$seq->traversaldir = $direction;
}
return $seq;
}
} else {
$children = scorm_get_available_children($activity);
if (!empty($children)) {
if (isset($parent->flow) && $parent->flow == true) {
$seq->traversaldir = 'forward';
$seq->nextactivity = $children[0];
return $seq;
} else {
$seq->traversaldir = 'backward';
$seq->nextactivity = $children[count($children) - 1];
return $seq;
}
} else {
$seq->traversaldir = null;
$seq->nextactivity = null;
$seq->exception = 'SB.2.1-2';
return $seq;
}
}
}
}
}
function scorm_seq_choice_flow_tree($constrained, $traverse, $seq)
{
$islast = false;
$parent = scorm_get_parent($constrained);
if ($traverse == 'forward') {
$preord = scorm_get_preorder($constrained);
if (sizeof($preorder) == 0 || sizeof($preorder) == 0 && ($preorder[0]->id = $constrained->id)) {
$islast = true;
//the function is the last activity available
}
if ($constrained->parent == '/' || $islast) {
$seq->nextactivity = null;
return $seq;
}
$avchildren = scorm_get_available_children($parent);
//available children
if ($avchildren[sizeof($avchildren) - 1]->id == $constrained->id) {
$seq = scorm_seq_choice_flow_tree($parent, 'forward', $seq);
return $seq;
} else {
$i = 0;
while ($i < sizeof($avchildren)) {
if ($avchildren[$i]->id == $constrained->id) {
$seq->nextactivity = $avchildren[$i + 1];
return $seq;
} else {
$i++;
}
}
}
}
if ($traverse == 'backward') {
if ($constrained->parent == '/') {
$seq->nextactivity = null;
return $seq;
}
$avchildren = scorm_get_available_children($parent);
//available children
if ($avchildren[0]->id == $constrained->id) {
$seq = scorm_seq_choice_flow_tree($parent, 'backward', $seq);
return $seq;
} else {
$i = sizeof($avchildren) - 1;
while ($i >= 0) {
if ($avchildren[$i]->id == $constrained->id) {
$seq->nextactivity = $avchildren[$i - 1];
return $seq;
} else {
$i--;
}
}
}
}
}
