public function OnPostback()
 {
     # If there's no id, ensure no match object is created. Page will then display a "match not found" message.
     # There's a separate page for adding matches, even for admins.
     if (!$this->editor->GetDataObjectId()) {
         return;
     }
     # Get the submitted match
     $this->match = $this->editor->GetDataObject();
     $check_match = $this->match;
     # Because this is a new request, if the user isn't admin we need to reverify whether this is the match owner
     # before letting anything happen. Can't trust that info from a postback so MUST go to the database to check it.
     if (!$this->b_user_is_match_admin) {
         $this->match_manager->ReadByMatchId(array($this->editor->GetDataObjectId()));
         $check_match = $this->match_manager->GetFirst();
         $this->b_user_is_match_owner = ($check_match instanceof Match and AuthenticationManager::GetUser()->GetId() == $check_match->GetAddedBy()->GetId());
         if ($this->b_user_is_match_owner) {
             # Set the owner of the match. This means the edit control knows who the owner is and therefore
             # whether to display the fixture editor on an invalid postback
             $this->match->SetAddedBy(AuthenticationManager::GetUser());
         } else {
             # If user is neither admin nor owner, they won't have the team info. Get it from the $check_match so
             # that the match title can be updated correctly with a changed result.
             $this->match->SetHomeTeam($check_match->GetHomeTeam());
             $this->match->SetAwayTeam($check_match->GetAwayTeam());
         }
     }
     # Don't wan't to edit tournaments on this page, so even as admin make sure we're not trying to save one.
     # If user's not admin, can't change the match type, so find out what that is from the db too. For admin,
     # $check_match is the submitted one as the match type might've been changed.
     $this->b_is_tournament = $check_match->GetMatchType() == MatchType::TOURNAMENT;
     # Check whether cancel was clicked
     if ($this->editor->CancelClicked()) {
         # If so, get the match's short URL and redirect
         $this->match_manager->ExpandMatchUrl($this->match);
         $this->Redirect($this->match->GetNavigateUrl());
     }
     # save data if valid
     if ($this->IsValid() and !$this->b_is_tournament) {
         # Check whether the user has permission to update the fixture as well as the result
         if ($this->b_user_is_match_admin or $this->b_user_is_match_owner) {
             # Get the ground name from the database. This is used when compiling an email about the updated match result.
             if ($this->match->GetGround() instanceof Ground and $this->match->GetGround()->GetId() and !$this->match->GetGround()->GetName()) {
                 require_once 'stoolball/ground-manager.class.php';
                 $ground_manager = new GroundManager($this->GetSettings(), $this->GetDataConnection());
                 $ground_manager->ReadById(array($this->match->GetGround()->GetId()));
                 if ($ground_manager->GetCount()) {
                     $this->match->SetGround($ground_manager->GetFirst());
                 }
                 unset($ground_manager);
             }
             $this->match_manager->SaveFixture($this->match);
             if ($this->b_user_is_match_admin) {
                 $this->match_manager->SaveSeasons($this->match, false);
             }
             $this->editor->SetNavigateUrl($this->match->GetEditNavigateUrl());
             # because edit URL may have changed
         }
         # Save the result
         $this->match_manager->SaveIfPlayed($this->match);
         $this->match_manager->SaveWhoWonTheToss($this->match);
         $this->match_manager->SaveWhoBattedFirst($this->match);
         # If match didn't happen or the teams aren't known yet, save and finish, otherwise go to next page
         $result = $this->match->Result()->GetResultType();
         if ($result == MatchResult::HOME_WIN_BY_FORFEIT or $result == MatchResult::AWAY_WIN_BY_FORFEIT or $result == MatchResult::CANCELLED or $result == MatchResult::POSTPONED or $check_match->GetStartTime() > gmdate('U') or $this->b_user_is_match_admin and (!$this->match->GetHomeTeamId() or !$this->match->GetAwayTeamId())) {
             # Match may have been updated so, first, send an email
             $this->match_manager->NotifyMatchModerator($this->match->GetId());
             http_response_code(303);
             $this->Redirect($this->match->GetNavigateUrl());
         } else {
             http_response_code(303);
             $this->Redirect($this->match->EditScorecardUrl());
         }
     }
 }