ButtonBlock.php

<?php

namespace Drupal\projects\Plugin\Block;

use Drupal\Component\Serialization\Json;
use Drupal\Core\Block\Annotation\Block;
use Drupal\Core\Block\BlockBase;
use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Provides an example block.
 *
 * @Block(
 *   id = "button_block",
 *   admin_label = @Translation("Button Block"),
 *   category = @Translation("Custom")
 * )
 */
class ButtonBlock extends BlockBase implements ContainerFactoryPluginInterface {

  protected $currentUser;

  protected $routeMatch;

  protected $entityManager;

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
    $instance = new static($configuration, $plugin_id, $plugin_definition);
    $instance->currentUser = $container->get('current_user');
    $instance->routeMatch = $container->get('current_route_match');
    $instance->entityManager = $container->get('entity_type.manager');
    return $instance;
  }

  /**
   * {@inheritdoc}
   */
  public function build() {
    $button = [];
    $project = $this->routeMatch->getParameter('node');
    if ($this->currentUser->hasPermission('administer projects configuration') && $project) {
      $button['container'] = [
        '#type' => 'actions',
        '#title' => $this->t('Actions for project "@project"', ['@project' => $project->label()])
      ];
      switch ($project->field_status->value) {
        case 0:
          $button['container']['start'] = [
            '#type' => 'submit',
            '#value' => $this->t('Start project'),
            '#submit' => [get_class($this), 'startProject'],
            '#attributes' => [
              'class' => ['btn', 'btn-success'],
              ],
          ];
          break;
        case 1:
          $button['container']['profit'] = [
            '#type' => 'link',
            '#title' => $this->t('Profit'),
            '#attributes' => [
              'class' => ['use-ajax', 'btn', 'btn-primary'],
              'data-dialog-type' => 'modal',
              'data-dialog-options' => Json::encode([
                'width' => 'auto',
                'maxWidth' => 600,
                'fluid' => true,
              ]),
            ],
            '#url' =>  \Drupal\Core\Url::fromRoute('entity.node.project_profit_form',  ['node' => $project->id()]),
            '#attached' => [
              'library' => ['core/drupal.dialog.ajax'],
            ],
          ];
          $button['container']['stop'] = [
            '#type' => 'submit',
            '#value' => $this->t('Close project'),
            '#submit' => [get_class($this), 'closeProject'],
            '#attributes' => [
              'class' => ['btn', 'btn-danger'],
            ],
          ];
          break;
        case 5:
          $button = [];
      }
      return $button;
    }
    return [];
  }

  function startProject() {
    dpm(get_class($this));
  }

  function closeProject() {
    dpm(get_class($this));
  }
}