public function MessagesContext::getRuntimeContexts in Better Messages 8

Gets runtime context values for the given context IDs.

For context-aware plugins to function correctly, all of the contexts that they require must be populated with values. So this method should set a value for each context that it adds. For example:

  // Determine a specific node to pass as context to a block.
  $node = ...

  // Set that specific node as the value of the 'node' context.
  $context = EntityContext::fromEntity($node);
  return ['node' => $context];

On the other hand, there are cases, on which providers no longer are possible to provide context objects, even without the value, so the caller should not expect it.

Parameters

string[] $unqualified_context_ids: The requested context IDs. The context provider must only return contexts for those IDs.

Return value

\Drupal\Core\Plugin\Context\ContextInterface[] The determined available contexts, keyed by the unqualified context_id.

Overrides ContextProviderInterface::getRuntimeContexts

See also

\Drupal\Core\Plugin\Context\ContextProviderInterface:getAvailableContexts()

File

src/ContextProvider/MessagesContext.php, line 32

Class

MessagesContext

Provides current Drupal status messages as a context.

Namespace

Drupal\better_messages\ContextProvider

Code

public function getRuntimeContexts(array $unqualified_context_ids) {
  $result = [];
  $context_definition = new ContextDefinition('map', NULL, FALSE);
  $context = new Context($context_definition, $this
    ->getMessages());
  $cacheability = new CacheableMetadata();

  // We cannot cache this context as literally a few lines below some message
  // might be added.
  $cacheability
    ->setCacheMaxAge(0);

  // Since messages are stored in session, we must vary by it.
  $cacheability
    ->addCacheContexts([
    'session',
  ]);
  $context
    ->addCacheableDependency($cacheability);
  $result['better_messages'] = $context;
  return $result;
}