An exception occurred: Cannot send headers; headers already sent in

[AndyB]

In my add-on Inactive Members, I would like to display in the browser the username of the email being sent. Currently if 1000 emails are sent, the browser sits there without any confirmation until it's done.

This is an example of my test code that runs just once, but will echo 1~100 to let me know it's working.

// get visitor data
$visitor = XenForo_Visitor::getInstance();

// username
$username = $visitor['username'];

// email
$email = $visitor['email'];

// define user variable
$user = array(
    'username' => $username,
    'email' => $email
);

// prepare mailParams                  
$mailParams = array(
    'user' => $user,
    'subject' => $subject,
    'message' => $message
);
  
// prepare mail variable
$mail = XenForo_Mail::create('inactivemembers_contact', $mailParams);

// send mail to queue
$mail->queue($user['email'], $user['username']);

$count = 100;

for ($i=0; $i<$count; $i++)
{      
    echo $i . '<br />';
    ob_flush();              
}

This echo's 1 through 100 just fine, but after that instead of returning this error message is displayed:

An exception occurred: Cannot send headers; headers already sent in /home/southbay/www/forums/library/Andy/InactiveMembers/ControllerPublic/InactiveMembers.php, line 397 in /home/southbay/www/forums/library/Zend/Controller/Response/Abstract.php on line 321

    Zend_Controller_Response_Abstract->canSendHeaders() in Zend/Controller/Response/Abstract.php at line 115
    Zend_Controller_Response_Abstract->setHeader() in XenForo/ViewRenderer/Abstract.php at line 63
    XenForo_ViewRenderer_Abstract->__construct() in XenForo/ViewRenderer/HtmlPublic.php at line 18
    XenForo_ViewRenderer_HtmlPublic->__construct() in XenForo/Dependencies/Public.php at line 212
    XenForo_Dependencies_Public->getViewRenderer() in XenForo/FrontController.php at line 537
    XenForo_FrontController->_getViewRenderer() in XenForo/FrontController.php at line 141
    XenForo_FrontController->run() in /home/southbay/www/forums/index.php at line 13

Does anyone know how I can properly echo something to the browser so the admin knows the emails are being sent.

Thank you.

 

[AndyB]

I resolved this by putting an exit() after the for loop. I've included a phrase telling the user to press the back button to return.