Contao\CoreBundle\DataContainer\PaletteManipulator::applyLegend PHP Метод

    private function applyLegend(array &$config, array $action)
    {
        // Legend already exists, do nothing
        if (array_key_exists($action['name'], $config)) {
            return;
        }
        $template = [$action['name'] => ['fields' => [], 'hide' => $action['hide']]];
        if (self::POSITION_PREPEND === $action['position']) {
            $config = $template + $config;
            return;
        }
        if (self::POSITION_APPEND === $action['position']) {
            $config += $template;
            return;
        }
        foreach ($action['parents'] as $parent) {
            if (array_key_exists($parent, $config)) {
                $offset = array_search($parent, array_keys($config), true);
                $offset += (int) (self::POSITION_AFTER === $action['position']);
                // Necessary because array_splice() would remove the keys from the replacement array
                $before = array_splice($config, 0, $offset);
                $config = $before + $template + $config;
                return;
            }
        }
        // If everything fails, append the new legend at the end
        $config += $template;
    }