Question

I am trying to create a new entity using an existing entity (passed in) set set all the values . Here is the class method that I am using in the Managed Object Subclass:

+(FlightManifest *)getNextFlightManifestLegWithFlightManifest:(FlightManifest *)fm {
    // Get the current context
    NSManagedObjectContext *moc = [NSManagedObjectContext MR_contextForCurrentThread];

    // Set a var to the cur leg so we can use it to increment the leg number later
    NSInteger curLeg = [fm.leg intValue];

    // Check to see if we already have the next leg saved
    if ([self getFlightManifestWithTripID:fm.tripid andLeg:[NSNumber numberWithInt:curLeg + 1]] !=nil) {
        return [self getFlightManifestWithTripID:fm.tripid andLeg:[NSNumber numberWithInt:curLeg + 1]];
    } else {
        // Create a new leg using the passed in FlightManifest for the values
        FlightManifest *newFM = [FlightManifest MR_createInContext:moc];  

        // Set the value of the newly created object to the one passed in
        newFM = fm;

        // Increment the leg number
        newFM.leg = [NSNumber numberWithInt:curLeg + 1];

        // Save the object
        [moc MR_save];

        return newFM;
    }
}

And I call it like this:

- (IBAction)nextLegButtonPressed:(id)sender {

    currentFlight = [FlightManifest getNextFlightManifestLegWithFlightManifest:currentFlight];
    self.legNumberLabel.text = [currentFlight.leg stringValue];
    [self reloadLegsTableViewData];
}

What is happening is that I am changing the current entity instead of creating a new one. Any ideas on what I am doing wrong?

Answer 1

This may seem obvious, but this line seems suspicious:

// Set the value of the newly created object to the one passed in
    newFM = fm;

This would make the code after use the existing fm object…and change the one your trying to copy…