function CachedStrategy::processNestedPlaceholders

Fetch any nested placeholders from cache.

Placeholders returned from cache may have placeholders in #attached, which can themselves be fetched from the cache. By recursively processing the placeholders here, we're able to use multiple cache get to fetch the cache items at each level of recursion.

File

core/lib/Drupal/Core/Render/Placeholder/CachedStrategy.php, line 40

Class

CachedStrategy

Looks up placeholders in the render cache and returns those we could find.

Namespace

Code

private function processNestedPlaceholders(array $placeholders) : array {
    $sets = [];
    foreach ($placeholders as $key => $placeholder) {
        if (!empty($placeholder['#attached']['placeholders'])) {
            $sets[] = $placeholder['#attached']['placeholders'];
        }
    }
    if ($sets) {
        $cached = $this->renderCache
            ->getMultiple(...array_merge($sets));
        if ($cached) {
            $cached = $this->processNestedPlaceholders($cached);
            foreach ($placeholders as $key => $placeholder) {
                if (!empty($placeholder['#attached']['placeholders'])) {
                    $placeholders[$key]['#attached']['placeholders'] = array_replace($placeholder['#attached']['placeholders'], $cached);
                }
            }
        }
    }
    return $placeholders;
}