class ViewsBlock

class ViewsBlock implements ContainerDeriverInterface {
    
    /**
     * List of derivative definitions.
     *
     * @var array
     */
    protected $derivatives = [];
    
    /**
     * The base plugin ID.
     *
     * @var string
     */
    protected $basePluginId;
    
    /**
     * The view storage.
     *
     * @var \Drupal\Core\Entity\EntityStorageInterface
     */
    protected $viewStorage;
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, $base_plugin_id) {
        return new static($base_plugin_id, $container->get('entity_type.manager')
            ->getStorage('view'));
    }
    
    /**
     * Constructs a ViewsBlock object.
     *
     * @param string $base_plugin_id
     *   The base plugin ID.
     * @param \Drupal\Core\Entity\EntityStorageInterface $view_storage
     *   The entity storage to load views.
     */
    public function __construct($base_plugin_id, EntityStorageInterface $view_storage) {
        $this->basePluginId = $base_plugin_id;
        $this->viewStorage = $view_storage;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDerivativeDefinition($derivative_id, $base_plugin_definition) {
        if (!empty($this->derivatives) && !empty($this->derivatives[$derivative_id])) {
            return $this->derivatives[$derivative_id];
        }
        $this->getDerivativeDefinitions($base_plugin_definition);
        return $this->derivatives[$derivative_id];
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDerivativeDefinitions($base_plugin_definition) {
        // Check all Views for block displays.
        foreach ($this->viewStorage
            ->loadMultiple() as $view) {
            // Do not return results for disabled views.
            if (!$view->status()) {
                continue;
            }
            $executable = $view->getExecutable();
            $executable->initDisplay();
            foreach ($executable->displayHandlers as $display) {
                
                /** @var \Drupal\views\Plugin\views\display\DisplayPluginInterface $display */
                // Add a block plugin definition for each block display.
                if (isset($display) && !empty($display->definition['uses_hook_block'])) {
                    $delta = $view->id() . '-' . $display->display['id'];
                    $admin_label = $display->getOption('block_description');
                    if (empty($admin_label)) {
                        if ($display->display['display_title'] == $display->definition['title']) {
                            $admin_label = $view->label();
                        }
                        else {
                            // Allow translators to control the punctuation. Plugin
                            // definitions get cached, so use TranslatableMarkup() instead of
                            // $this->t() to avoid double escaping when $admin_label is rendered
                            // during requests that use the cached definition.
                            $admin_label = new TranslatableMarkup('@view: @display', [
                                '@view' => $view->label(),
                                '@display' => $display->display['display_title'],
                            ]);
                        }
                    }
                    $this->derivatives[$delta] = [
                        'category' => $display->getOption('block_category'),
                        'admin_label' => $admin_label,
                        'config_dependencies' => [
                            'config' => [
                                $view->getConfigDependencyName(),
                            ],
                        ],
                    ];
                    // Look for arguments and expose them as context.
                    foreach ($display->getHandlers('argument') as $argument_name => $argument) {
                        
                        /** @var \Drupal\views\Plugin\views\argument\ArgumentPluginBase $argument */
                        if ($context_definition = $argument->getContextDefinition()) {
                            $this->derivatives[$delta]['context_definitions'][$argument_name] = $context_definition;
                        }
                    }
                    $this->derivatives[$delta] += $base_plugin_definition;
                }
            }
        }
        return $this->derivatives;
    }

}