Display notification messages in Magento 2

If you need your module to display messages via Magento notification system, we will show you the example of the code you should use.

If you are using a controller, then most probably you have extended

\Magento\Framework\App\Action\Action

This injects the \Magento\Framework\Message\ManagerInterface object in its __construct function using the

\Magento\Framework\App\Action\Context $context object

So to display a message,

Success -

$this->messageManager->addSuccess( __('This is your success message.') );

Error -

$this->messageManager->addError( __('This is your error message.') );

Warning -

$this->messageManager->addWarning( __('This is your warning message.') );

Notice -

$this->messageManager->addNotice( __('This is your notice message.') );

In other case

class TonyBlog
{

    /**
    * @var \Magento\Framework\Message\ManagerInterface
    */
    private $messageManager;

    public function __construct(
        \Magento\Framework\Message\ManagerInterface $messageManager
    )
    {
        $this->messageManager = $messageManager;
    }

    public function tonyFunction()
    {
        $this->messageManager->addSuccess('Add your success message');
    }

}

That's all.