A trick: a «before» plugin can return nothing if it needs not modify any argument

dmitrii_fediuk · January 7, 2016, 1:33am

magento/magento2/blob/c58d2d/lib/internal/Magento/Framework/Interception/Interceptor.php#L118-L126


foreach ($pluginInfo[DefinitionInterface::LISTENER_BEFORE] as $code) {
    $beforeResult = call_user_func_array(
        [$this->pluginList->getPlugin($this->subjectType, $code), 'before'. $capMethod],
        array_merge([$this], $arguments)
    );
    if ($beforeResult) {
        $arguments = $beforeResult;
    }
}

An example

github.com

magento/magento2/blob/c58d2d/app/code/Magento/Catalog/Model/Indexer/Product/Eav/Plugin/StoreView.php#L25-L41


/**
 * Before save handler
 *
 * @param \Magento\Store\Model\ResourceModel\Store $subject
 * @param \Magento\Framework\Model\AbstractModel $object
 *
 * @return void
 * @SuppressWarnings(PHPMD.UnusedFormalParameter)
 */
public function beforeSave(
    \Magento\Store\Model\ResourceModel\Store $subject,
    \Magento\Framework\Model\AbstractModel $object
) {
    if ((!$object->getId() || $object->dataHasChangedFor('group_id')) && $object->getIsActive()) {
        $this->_indexerEavProcessor->markIndexerAsInvalid();
    }
}

dmitrii_fediuk · January 7, 2016, 2:28am