/**
* Remove unit
*
* This function is used to remove a unit from the content tree
* <br/>Example:
* <code>
* $content = new EfrontContentTree(4); //Initialize content tree for lesson with id 4
* $content -> removeNode(57); //Remove the unit 57 and all of its subunits
* </code>
*
* @param int $removeId The unit id that will be removed
* @since 3.5.0
* @access public
*/
public function removeNode($removeId)
{
$iterator = new EfrontNodeFilterIterator(new RecursiveIteratorIterator($this->tree, RecursiveIteratorIterator::SELF_FIRST));
//Get an iterator for the current tree. This iterator returns only whole unit arrays and not unit members separately (such as id, timestamp etc)
$iterator->rewind();
//Initialize iterator
while ($iterator->valid() && $iterator->key() != $removeId) {
//Forward iterator index until you reach the designated element, which has an index equal to the unit id that will be removed
$iterator->next();
}
if ($iterator->valid()) {
$iterator->current()->delete();
//Delete the current unit from the database
$previousUnit = $this->getPreviousNode($iterator->key());
//Get the deleted unit's previous unit
$iterator->offsetUnset($removeId);
//Delete the unit from the content tree
if ($previousUnit) {
//If we are deleting the first unit, there is no previous unit
$nextUnit = $this->getNextNode($previousUnit['id']);
//Get the previous unit's next unit, which still points to the old unit
if ($nextUnit) {
//If we are deleting the last unit, there is not next unit
$nextUnit['previous_content_ID'] = $previousUnit['id'];
//Update the next unit to point at the deleted unit' previous unit
$nextUnit->persist();
//Persist these changes to the database
}
} else {
$firstUnit = $this->getFirstNode();
//If we deleted the first unit, then we need to set the new first unit to have 0 as previous unit
if ($firstUnit) {
//...Unless the deleted unit was the last content unit
$firstUnit['previous_content_ID'] = 0;
$firstUnit->persist();
//Persist these changes to the database
}
}
} else {
throw new EfrontContentException(_UNITDOESNOTEXIST . ': ' . $removeId, EfrontContentException::UNIT_NOT_EXISTS);
}
}
