Method getOptions

/**
 * Method to get the field options for category
 * Use the extension attribute in a form to specify the.specific extension for
 * which categories should be displayed.
 * Use the show_root attribute to specify whether to show the global category root in the list.
 *
 * @return  array    The field option objects.
 *
 * @since   1.6
 */
protected function getOptions()
{
    $options = array();
    $extension = $this->element['extension'] ? (string) $this->element['extension'] : (string) $this->element['scope'];
    $published = (string) $this->element['published'];
    $language = (string) $this->element['language'];
    // Load the category options for a given extension.
    if (!empty($extension)) {
        // Filter over published state or not depending upon if it is present.
        $filters = array();
        if ($published) {
            $filters['filter.published'] = explode(',', $published);
        }
        // Filter over language depending upon if it is present.
        if ($language) {
            $filters['filter.language'] = explode(',', $language);
        }
        if ($filters === array()) {
            $options = HTMLHelper::_('category.options', $extension);
        } else {
            $options = HTMLHelper::_('category.options', $extension, $filters);
        }
        // Verify permissions.  If the action attribute is set, then we scan the options.
        if ((string) $this->element['action']) {
            // Get the current user object.
            $user = Factory::getUser();
            foreach ($options as $i => $option) {
                /*
                 * To take save or create in a category you need to have create rights for that category
                 * unless the item is already in that category.
                 * Unset the option if the user isn't authorised for it. In this field assets are always categories.
                 */
                if ($user->authorise('core.create', $extension . '.category.' . $option->value) === false) {
                    unset($options[$i]);
                }
            }
        }
        if (isset($this->element['show_root'])) {
            array_unshift($options, HTMLHelper::_('select.option', '0', Text::_('JGLOBAL_ROOT')));
        }
    } else {
        Log::add(Text::_('JLIB_FORM_ERROR_FIELDS_CATEGORY_ERROR_EXTENSION_EMPTY'), Log::WARNING, 'jerror');
    }
    // Merge any additional options in the XML definition.
    $options = array_merge(parent::getOptions(), $options);
    return $options;
}