How to add a message to the current session (to make it shown on the screen after a controller redirection)?

dmitry_fedyuk · March 18, 2016, 10:45am

API

Use the \Magento\Framework\Message\ManagerInterface:

magento/magento2/blob/8fd3e8/lib/internal/Magento/Framework/Message/ManagerInterface.php#L6-L13


namespace Magento\Framework\Message;
/**
 * Adds different types of messages to the session, and allows access to existing messages.
 *
 * @api
 */
interface ManagerInterface

The interface is implemented by the \Magento\Framework\Message\Manager class:

github.com

magento/magento2/blob/8fd3e8/app/etc/di.xml#L70-L70


<preference for="Magento\Framework\Message\ManagerInterface" type="Magento\Framework\Message\Manager" />

A usage example

github.com

magento/magento2/blob/8fd3e8/app/code/Magento/Sales/Controller/Adminhtml/Order/VoidPayment.php#L20-L30


try {
    // workaround for backwards compatibility
    $order->getPayment()->void(new \Magento\Framework\DataObject());
    $order->save();
    $this->messageManager->addSuccess(__('The payment has been voided.'));
} catch (\Magento\Framework\Exception\LocalizedException $e) {
    $this->messageManager->addError($e->getMessage());
} catch (\Exception $e) {
    $this->messageManager->addError(__('We can\'t void the payment right now.'));
    $this->_objectManager->get('Psr\Log\LoggerInterface')->critical($e);
}

How to diagnose the «We can’t void the payment right now» failure?