how to: use $message->render(); in typo3 v 4.5 - typo3

Question

I need to display a flash message but the message gets gobbled up by another extension, so can I do something like this:
in my controller:
$message = t3lib_div::makeInstance('t3lib_FlashMessage', 'Valid.', 'Message Header', t3lib_FlashMessage::OK, FALSE );
$message->render();
echo "<br/>".__FUNCTION__.__LINE__."<br/>";
$this->redirect('validate_success');
and have the message show up somewhere on my page, but where, what tag? Or should I handle the passing of messages differently altogether?
I use typo3 v 4.5.3 extbase 1.3
Thanks

Answer 1

If you redirect with $this->redirect() the echo in the same action will never appear.
Correct usage of FlashMessage in TYPO3 4.5
In your controller/action:
$this->flashMessageContainer->add("Your message body", "Your message header", t3lib_FlashMessage::OK);
This will add the FlashMessage to a container which holds all FlashMessages in a global scope.
In your fluid template of the action you redirected to:
<f:flashMessages renderMode="div" />
Alternatively you can use renderMode="ul".

Answer 2

This is how I do it now:
$this->redirect('validate_failed', 'Coupon', 'coupons', array('coupon' => $result, 'filename' => $filename, 'message' => 'Expired.'));
avoiding the whole flashmessage thing and passing a other stuff I want as well.
and this is my couponcontroller method that catches that redirect:
/**
* action validate
* #param Tx_Coupons_Domain_Model_Coupon $coupon
* #param string $filename
* #param string $message
* #return void
*/
public function validate_failedAction(Tx_Coupons_Domain_Model_Coupon $coupon = NULL, $filename = '', $message = '') {
$this->view->assign('coupon', $coupon);
$this->view->assign('filename', $filename);
$this->view->assign('message', $message);
}