public function GroupOperationsBlock::build in Group 8

Same name and namespace in other branches

1. 2.0.x src/Plugin/Block/GroupOperationsBlock.php \Drupal\group\Plugin\Block\GroupOperationsBlock::build()

Builds and returns the renderable array for this block plugin.

If a block should not be rendered because it has no content, then this method must also ensure to return no content: it must then only return an empty array, or an empty array with #cache set (with cacheability metadata indicating the circumstances for it being empty).

Return value

array A renderable array representing the content of the block.

Overrides BlockPluginInterface::build

See also

\Drupal\block\BlockViewBuilder

File

src/Plugin/Block/GroupOperationsBlock.php, line 24

Class

GroupOperationsBlock

Provides a block with operations the user can perform on a group.

Namespace

Drupal\group\Plugin\Block

Code

public function build() {
  $build = [];

  // The operations available in this block vary per the current user's group
  // permissions. It obviously also varies per group, but we cannot know for
  // sure how we got that group as it is up to the context provider to
  // implement that. This block will then inherit the appropriate cacheable
  // metadata from the context, as set by the context provider.
  $cacheable_metadata = new CacheableMetadata();
  $cacheable_metadata
    ->setCacheContexts([
    'user.group_permissions',
  ]);

  /** @var \Drupal\group\Entity\GroupInterface $group */
  if (($group = $this
    ->getContextValue('group')) && $group
    ->id()) {
    $links = [];

    // Retrieve the operations and cacheable metadata from the installed
    // content plugins.
    foreach ($group
      ->getGroupType()
      ->getInstalledContentPlugins() as $plugin) {

      /** @var \Drupal\group\Plugin\GroupContentEnablerInterface $plugin */
      $links += $plugin
        ->getGroupOperations($group);
      $cacheable_metadata = $cacheable_metadata
        ->merge($plugin
        ->getGroupOperationsCacheableMetadata());
    }
    if ($links) {

      // Allow modules to alter the collection of gathered links.
      \Drupal::moduleHandler()
        ->alter('group_operations', $links, $group);

      // Sort the operations by weight.
      uasort($links, '\\Drupal\\Component\\Utility\\SortArray::sortByWeightElement');

      // Create an operations element with all of the links.
      $build['#type'] = 'operations';
      $build['#links'] = $links;
    }
  }

  // Set the cacheable metadata on the build.
  $cacheable_metadata
    ->applyTo($build);
  return $build;
}