class WorkspacePublishForm

class WorkspacePublishForm extends ConfirmFormBase implements WorkspaceFormInterface, ContainerInjectionInterface {
    
    /**
     * The workspace that will be published.
     *
     * @var \Drupal\workspaces\WorkspaceInterface
     */
    protected $workspace;
    
    /**
     * The workspace operation factory.
     *
     * @var \Drupal\workspaces\WorkspaceOperationFactory
     */
    protected $workspaceOperationFactory;
    
    /**
     * The entity type manager.
     *
     * @var \Drupal\Core\Entity\EntityTypeManagerInterface
     */
    protected $entityTypeManager;
    
    /**
     * Constructs a new WorkspacePublishForm.
     *
     * @param \Drupal\workspaces\WorkspaceOperationFactory $workspace_operation_factory
     *   The workspace operation factory service.
     * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
     *   The entity type manager.
     */
    public function __construct(WorkspaceOperationFactory $workspace_operation_factory, EntityTypeManagerInterface $entity_type_manager) {
        $this->workspaceOperationFactory = $workspace_operation_factory;
        $this->entityTypeManager = $entity_type_manager;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        return new static($container->get('workspaces.operation_factory'), $container->get('entity_type.manager'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function getFormId() {
        return 'workspace_publish_form';
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state, WorkspaceInterface $workspace = NULL) {
        $this->workspace = $workspace;
        $form = parent::buildForm($form, $form_state);
        $workspace_publisher = $this->workspaceOperationFactory
            ->getPublisher($this->workspace);
        $args = [
            '%source_label' => $this->workspace
                ->label(),
            '%target_label' => $workspace_publisher->getTargetLabel(),
        ];
        $form['#title'] = $this->t('Publish %source_label workspace', $args);
        // List the changes that can be pushed.
        if ($source_rev_diff = $workspace_publisher->getDifferringRevisionIdsOnSource()) {
            $total_count = $workspace_publisher->getNumberOfChangesOnSource();
            $form['description'] = [
                '#theme' => 'item_list',
                '#title' => $this->formatPlural($total_count, 'There is @count item that can be published from %source_label to %target_label', 'There are @count items that can be published from %source_label to %target_label', $args),
                '#items' => [],
                '#total_count' => $total_count,
            ];
            foreach ($source_rev_diff as $entity_type_id => $revision_difference) {
                $form['description']['#items'][$entity_type_id] = $this->entityTypeManager
                    ->getDefinition($entity_type_id)
                    ->getCountLabel(count($revision_difference));
            }
            $form['actions']['submit']['#value'] = $this->formatPlural($total_count, 'Publish @count item to @target', 'Publish @count items to @target', [
                '@target' => $workspace_publisher->getTargetLabel(),
            ]);
        }
        else {
            // If there are no changes to push or pull, show an informational message.
            $form['help'] = [
                '#markup' => $this->t('There are no changes that can be published from %source_label to %target_label.', $args),
            ];
            // Do not allow the 'Publish' operation if there's nothing to publish.
            $form['actions']['submit']['#value'] = $this->t('Publish');
            $form['actions']['submit']['#disabled'] = TRUE;
        }
        return $form;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getQuestion() {
        return $this->t('Would you like to publish the contents of the %label workspace?', [
            '%label' => $this->workspace
                ->label(),
        ]);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDescription() {
        return $this->t('Publish workspace contents.');
    }
    
    /**
     * {@inheritdoc}
     */
    public function getCancelUrl() {
        return Url::fromRoute('entity.workspace.collection', [], [
            'query' => \Drupal::destination()->getAsArray(),
        ]);
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitForm(array &$form, FormStateInterface $form_state) {
        $workspace = $this->workspace;
        try {
            $workspace->publish();
            $this->messenger()
                ->addMessage($this->t('Successful publication.'));
        } catch (WorkspaceAccessException $e) {
            $this->messenger()
                ->addMessage($e->getMessage(), 'error');
        } catch (\Exception $e) {
            $this->messenger()
                ->addMessage($this->t('Publication failed. All errors have been logged.'), 'error');
        }
    }

}