function EntityReferenceFormatterBase::view

Overrides FormatterBase::view

See also

::prepareView()

::getEntitiesToView()

File

core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/EntityReferenceFormatterBase.php, line 75

Class

EntityReferenceFormatterBase

Parent plugin for entity reference formatters.

Namespace

Code

public function view(FieldItemListInterface $items, $langcode = NULL) {
    $elements = parent::view($items, $langcode);
    $field_level_access_cacheability = new CacheableMetadata();
    // Try to map the cacheability of the access result that was set at
    // _accessCacheability in getEntitiesToView() to the corresponding render
    // subtree. If no such subtree is found, then merge it with the field-level
    // access cacheability.
    foreach ($items as $delta => $item) {
        // Ignore items for which access cacheability could not be determined in
        // prepareView().
        if (!empty($item->_accessCacheability)) {
            if (isset($elements[$delta])) {
                CacheableMetadata::createFromRenderArray($elements[$delta])->merge($item->_accessCacheability)
                    ->applyTo($elements[$delta]);
            }
            else {
                $field_level_access_cacheability = $field_level_access_cacheability->merge($item->_accessCacheability);
            }
        }
    }
    // Apply the cacheability metadata for the inaccessible entities and the
    // entities for which the corresponding render subtree could not be found.
    // This causes the field to be rendered (and cached) according to the cache
    // contexts by which the access results vary, to ensure only users with
    // access to this field can view it. It also tags this field with the cache
    // tags on which the access results depend, to ensure users that cannot view
    // this field at the moment will gain access once any of those cache tags
    // are invalidated.
    $field_level_access_cacheability->merge(CacheableMetadata::createFromRenderArray($elements))
        ->applyTo($elements);
    return $elements;
}