public static function getFilePickerCallback($url, $popupSettings = [], $view = null)
    {
        $default = [
            'title' => 'elFinder',
            'width' => 900,
            'height' => 500,
        ];

        $settings = array_merge($default, $popupSettings);
        $settings['file'] = Url::to($url);

        $encodedSettings = Json::htmlEncode($settings);

        if ($view === null) {
            $view = Yii::$app->view;
        }
        HelperAsset::register($view);

        return new JsExpression("alexantr.elFinder.filePickerCallback($encodedSettings)");
    }