/**
* Overrides the method to add support for expanded tree nodes.
*
* The methods adds the `expanded` option which is used to store expanded tree nodes. The
* option is initialized with first level pages.
*/
protected function update_options(Options $options, array $modifiers)
{
$options = parent::update_options($options, $modifiers);
if (!isset($options->expanded)) {
$options->expanded = array();
}
if (isset($modifiers['expand']) || isset($modifiers['collapse'])) {
$expanded = array_flip($options->expanded);
if (isset($modifiers['expand'])) {
$nid = $this->expand_highlight = filter_var($modifiers['expand'], FILTER_VALIDATE_INT);
$expanded[$nid] = true;
}
if (isset($modifiers['collapse'])) {
unset($expanded[filter_var($modifiers['collapse'], FILTER_VALIDATE_INT)]);
}
$options->expanded = array_keys($expanded);
}
if ($options->order_by == 'title') {
$options->order_by = null;
}
if ($options->filters || $options->order_by || $options->search) {
$this->mode = 'flat';
}
return $options;
}
