class CommonTestController

class CommonTestController {
    
    /**
     * Returns links to the current page, with and without query strings.
     *
     * Using #type 'link' causes these links to be rendered with the link
     * generator.
     */
    public function typeLinkActiveClass() {
        return [
            'no_query' => [
                '#type' => 'link',
                '#title' => t('Link with no query string'),
                '#url' => Url::fromRoute('<current>'),
                '#options' => [
                    'set_active_class' => TRUE,
                ],
            ],
            'with_query' => [
                '#type' => 'link',
                '#title' => t('Link with a query string'),
                '#url' => Url::fromRoute('<current>'),
                '#options' => [
                    'query' => [
                        'foo' => 'bar',
                        'one' => 'two',
                    ],
                    'set_active_class' => TRUE,
                ],
            ],
            'with_query_reversed' => [
                '#type' => 'link',
                '#title' => t('Link with the same query string in reverse order'),
                '#url' => Url::fromRoute('<current>'),
                '#options' => [
                    'query' => [
                        'one' => 'two',
                        'foo' => 'bar',
                    ],
                    'set_active_class' => TRUE,
                ],
            ],
        ];
    }
    
    /**
     * Adds a JavaScript file and a CSS file with a query string appended.
     *
     * @return string
     *   An empty string.
     */
    public function jsAndCssQuerystring() {
        $attached = [
            '#attached' => [
                'library' => [
                    'node/drupal.node',
                ],
                'css' => [
                    drupal_get_path('module', 'node') . '/css/node.admin.css' => [],
                    // A relative URI may have a query string.
'/' . drupal_get_path('module', 'node') . '/node-fake.css?arg1=value1&arg2=value2' => [],
                ],
            ],
        ];
        return \Drupal::service('renderer')->renderRoot($attached);
    }
    
    /**
     * Prints a destination query parameter.
     *
     * @return \Symfony\Component\HttpFoundation\Response
     *   A new Response object containing a string with the destination query
     *   parameter.
     */
    public function destination() {
        $destination = \Drupal::destination()->getAsArray();
        $output = "The destination: " . Html::escape($destination['destination']);
        return new Response($output);
    }

}