public function tryToRegister()
  {
    if ($this->registerView->userClicksRegister()) {
      try {
        $regCredentials = $this->registerView->checkUser();
        $this->registerUser($regCredentials);
      } catch (\UsernameEmpty $e) {
        $this->registerView->setMessage('Username has too few characters, at least 3 characters.');
      } catch (\PasswordEmpty $e) {
        $this->registerView->setMessage('Password has too few characters, at least 6 characters.');
      } catch (\UsernameAndPasswordEmpty $e) {
        $this->registerView->setMessage('Username has too few characters, at least 3 characters. <br> Password has too few characters, at least 6 characters.');
      } catch (\PasswordDoesNotMatch $e) {
        $this->registerView->setMessage('Passwords do not match.');
      } catch (\UserAlreadyExist $e) {
        $this->registerView->setMessage('User exists, pick another username.');
      } catch (\ContainsHTML $e) {
        $this->registerView->setMessage('Username contains invalid characters.');
      }
    }
  }

  public function registerUser($credentials)
  {
    if (!$this->auth->doesUserExist($credentials)) {
      $this->auth->register($credentials);
      $this->storage->saveRegisterMessage('Registered new user.');
      header("Location: ?");
    }
  }