Conditional email notification on saveUser action?

Question

I have a simple task: one particular front-end form on a website is being used to update a logged in user's profile. It works. It uses the users.onSaveUser action.

I need to fire off notification emails when a particular input value is true on form submission.

My first attempt was a plugin that just watched the onSaveUser event; but while I could get that to send email, I could not seem to get access to the form fields in order to check whether the email should be sent or not. Therefore it sent emails whenever a user was saved, including when edited in the back-end.

Now I'm trying a plugin that has its own action - myPlugin/saveUser. But I am essentially duplicating the code in the existing users/saveUser function... and that makes it brittle. Is there not a way to get this done by just testing a field property and then passing everything over to the built-in users/saveUser action?

How would you do this?

Here's the simple plugin I had, which couldn't get the POST data and was therefor no good...

public function init() {
    craft()->on('users.saveUser', function(Event $event) {
        $this->requirePostRequest();

        // is in the relevant user group?
        if($event->params['user']->isInGroup('applications')){

            // check this is a submission from the front end form
            $applicationFormFrontend = craft()->request->getPost('applicationFormFrontend', 'default');

            // check the Consent field was true on this submission
            $consentGiven = craft()->request->getPost('fields[consentGiven]', 'default');

            NotifyPlugin::log("The value of applicationFormFrontend is $applicationFormFrontend.", LogLevel::Info);
            NotifyPlugin::log("The value of consentGiven is $consentGiven.", LogLevel::Info);

            if($applicationFormFrontend == '1' and $consentGiven == '1') {
                // Write Email

                ...

                // send the mail
                craft()->email->sendEmail($notificationEmail);
            }
        }
    });
}

EDIT, SOLUTION:

The reason I was not getting values for

$consentGiven = craft()->request->getPost('fields[consentGiven]', 'default');

is because it's the wrong style. It's why it was always getting 'default'. The fix is to use dot notation:

$consentGiven = craft()->request->getPost('fields.consentGiven', 'default');

The original code (as above) works with this modification.

Answer 1

You should be able to do something like this using the event:

craft()->on('users.onSaveUser', function(Event $event) {

  $testfield = craft()->request->getPost('someField');

  if($testfield)
  {
    // Send the email
  }

});

Answer 2

I think the following will complete all your requirements. If I've understood correctly you're trying to send an email notification by using a hidden field in a front end form. You don't want the email notification to send twice and you don't want it to send if a user is new or being saved from the control panel.

craft()->on('users.onSaveUser', function(Event $event) {

    $user = $event->params['user'];

    // Returns if the user is a new user
    if ( $event->params['isNewUser'] )
    {
      return
    }

    // If the user hasn't had an email before
    if ( $user->emailHasBeenSent == 0 )
    {
      // Get the frontEnd field value from the post request
      $frontEnd = craft()->request->getPost('frontEnd');

      // Check the frontEnd value (will be null if user saved through the CP)
      if ( $frontEnd == 1 )
      {
        // Send the email
        // Save the emailHasBeenSent on the user to true so we don't send another email the next time the user is saved
      }
    {

 });