class OpenOffCanvasDialogCommand

class OpenOffCanvasDialogCommand extends OpenDialogCommand {
    
    /**
     * The dialog width to use if none is provided.
     */
    const DEFAULT_DIALOG_WIDTH = 300;
    
    /**
     * Constructs an OpenOffCanvasDialogCommand object.
     *
     * The off-canvas dialog differs from the normal modal provided by
     * OpenDialogCommand in that a off-canvas has built in positioning and
     * behaviors. Drupal provides a built-in off-canvas dialog for this purpose,
     * so the selector is hard-coded in the call to the parent constructor.
     *
     * @param string $title
     *   The title of the dialog.
     * @param string|array $content
     *   The content that will be placed in the dialog, either a render array
     *   or an HTML string.
     * @param array $dialog_options
     *   (optional) Settings to be passed to the dialog implementation. Any
     *   jQuery UI option can be used. See http://api.jqueryui.com/dialog.
     * @param array|null $settings
     *   (optional) Custom settings that will be passed to the Drupal behaviors
     *   on the content of the dialog. If left empty, the settings will be
     *   populated automatically from the current request.
     * @param string $position
     *   (optional) The position to render the off-canvas dialog.
     */
    public function __construct($title, $content, array $dialog_options = [], $settings = NULL, $position = 'side') {
        parent::__construct('#drupal-off-canvas', $title, $content, $dialog_options, $settings);
        $this->dialogOptions['modal'] = FALSE;
        $this->dialogOptions['autoResize'] = FALSE;
        $this->dialogOptions['resizable'] = 'w';
        $this->dialogOptions['draggable'] = FALSE;
        $this->dialogOptions['drupalAutoButtons'] = FALSE;
        $this->dialogOptions['drupalOffCanvasPosition'] = $position;
        // @todo drupal.ajax.js does not respect drupalAutoButtons properly, pass an
        //   empty set of buttons until https://www.drupal.org/node/2793343 is in.
        $this->dialogOptions['buttons'] = [];
        if (empty($dialog_options['dialogClass'])) {
            $this->dialogOptions['dialogClass'] = "ui-dialog-off-canvas ui-dialog-position-{$position}";
        }
        // If no width option is provided then use the default width to avoid the
        // dialog staying at the width of the previous instance when opened
        // more than once, with different widths, on a single page.
        if (!isset($this->dialogOptions['width'])) {
            $this->dialogOptions['width'] = static::DEFAULT_DIALOG_WIDTH;
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function render() {
        $build = parent::render();
        $build['effect'] = 'fade';
        $build['speed'] = 1000;
        return $build;
    }

}