public function HelpBlock::build in Drupal 8

Same name and namespace in other branches

1. 9 core/modules/help/src/Plugin/Block/HelpBlock.php \Drupal\help\Plugin\Block\HelpBlock::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

core/modules/help/src/Plugin/Block/HelpBlock.php, line 88

Class

HelpBlock

Provides a 'Help' block.

Namespace

Drupal\help\Plugin\Block

Code

public function build() {

  // Do not show on a 403 or 404 page.
  if ($this->request->attributes
    ->has('exception')) {
    return [];
  }
  $implementations = $this->moduleHandler
    ->getImplementations('help');
  $build = [];
  $args = [
    $this->routeMatch
      ->getRouteName(),
    $this->routeMatch,
  ];
  foreach ($implementations as $module) {

    // Don't add empty strings to $build array.
    if ($help = $this->moduleHandler
      ->invoke($module, 'help', $args)) {

      // Convert strings to #markup render arrays so that they will XSS admin
      // filtered.
      $build[] = is_array($help) ? $help : [
        '#markup' => $help,
      ];
    }
  }
  return $build;
}