Editing users in grid - how to get ID & changed values?

$user->get('id')

$profile = $user->getOne('Profile');
$profile->get('blocked');

$id = $user->get('id');
$dbUser = $modx->getObject('modUser',$id);
$profile = $dbUser->getOne('Profile');
$email = $profile->get('email');
$fullname = $profile->get('fullname');

$before = $profile->get('blocked');
$after = $user->get('blocked');

<?php
	// get currently edited user
	$id = $user->get('id');
	$dbUser = $modx->getObject('modUser',$id);
     
    // get some profile information
	$profile = $dbUser->getOne('Profile');    

    // check if user was blocked and is still blocked now
	$before = $profile->get('blocked');
	$after = $user->get('blocked');

    // email settings
    $mailFrom = '[email protected]';
	$replyTo = '[email protected]';
    
    // set some defaults
    $mailFromName = 'XXX';
    $message = '';
    $mailChunk = '';
 
    // set unblock message chunk & subject only if user is  
    // currently blocked and after edit unblocked
    if (($before == 1) && ($after == 0 ) ){
        $mailChunk = 'userUnBlockedEmailTpl';
        $subject = 'Access granted';
    }

    // send mail if there is a chunk defined
    if ($mailChunk != ''){
 		
        $modx->setPlaceholder('fullname',$profile->get('fullname'));
        $modx->setPlaceholder('email',$profile->get('email'));
        $placeHolders = array('fullname' => $fullname, 'email' => $email);
        $message .= $modx->parseChunk($mailChunk, $placeHolders, '[[+', ']]');

        $modx->getService('mail', 'mail.modPHPMailer');
        $modx->mail->set(modMail::MAIL_BODY,$message);
        $modx->mail->set(modMail::MAIL_FROM,$mailFrom);
        $modx->mail->set(modMail::MAIL_FROM_NAME,$mailFromName);
        $modx->mail->set(modMail::MAIL_SENDER,$mailFrom);
        $modx->mail->set(modMail::MAIL_SUBJECT,$subject);
        $modx->mail->address('to',$email);
        $modx->mail->address('reply-to',$replyTo);
        $modx->mail->setHTML(true);
         
        if (!$modx->mail->send()) {
            $modx->log(modX::LOG_LEVEL_ERROR,'An error occurred while trying to send the email: '.$err);
        }
         
        $modx->mail->reset();
     
    }