function ChainedPlaceholderStrategy::processPlaceholders
Same name in other branches
- 8.9.x core/lib/Drupal/Core/Render/Placeholder/ChainedPlaceholderStrategy.php \Drupal\Core\Render\Placeholder\ChainedPlaceholderStrategy::processPlaceholders()
- 10 core/lib/Drupal/Core/Render/Placeholder/ChainedPlaceholderStrategy.php \Drupal\Core\Render\Placeholder\ChainedPlaceholderStrategy::processPlaceholders()
- 11.x core/lib/Drupal/Core/Render/Placeholder/ChainedPlaceholderStrategy.php \Drupal\Core\Render\Placeholder\ChainedPlaceholderStrategy::processPlaceholders()
Overrides PlaceholderStrategyInterface::processPlaceholders
File
-
core/
lib/ Drupal/ Core/ Render/ Placeholder/ ChainedPlaceholderStrategy.php, line 32
Class
- ChainedPlaceholderStrategy
- Renders placeholders using a chain of placeholder strategies.
Namespace
Drupal\Core\Render\PlaceholderCode
public function processPlaceholders(array $placeholders) {
if (empty($placeholders)) {
return [];
}
// Assert that there is at least one strategy.
assert(!empty($this->placeholderStrategies), 'At least one placeholder strategy must be present; by default the fallback strategy \\Drupal\\Core\\Render\\Placeholder\\SingleFlushStrategy is always present.');
$new_placeholders = [];
// Give each placeholder strategy a chance to replace all not-yet replaced
// placeholders. The order of placeholder strategies is well defined
// and this uses a variation of the "chain of responsibility" design pattern.
foreach ($this->placeholderStrategies as $strategy) {
$processed_placeholders = $strategy->processPlaceholders($placeholders);
assert(array_intersect_key($processed_placeholders, $placeholders) === $processed_placeholders, 'Processed placeholders must be a subset of all placeholders.');
$placeholders = array_diff_key($placeholders, $processed_placeholders);
$new_placeholders += $processed_placeholders;
if (empty($placeholders)) {
break;
}
}
return $new_placeholders;
}
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