Should I fix Xcode 5 'Semantic issue: undeclared selector'?

ios selector semantics xcode5
iOS-Coder picture iOS-Coder · Sep 2, 2013 · Viewed 23.1k times · Source

I'm trying to upgrade my app with Xcode5 but encountered a number of 'Semantic issues' in a third party library (being MagicalRecord). The quickest way to 'fix' this might be using the:

#pragma GCC diagnostic ignored "-Wundeclared-selector"

(from: How to get rid of the 'undeclared selector' warning)

compiler directive, but my gut-feeling says this is not the appropriate way to do this. A small code sample with the above error:

+ (NSEntityDescription *) MR_entityDescriptionInContext:(NSManagedObjectContext *)context {

    if ([self respondsToSelector:@selector(entityInManagedObjectContext:)]) 
    {
        NSEntityDescription *entity = [self performSelector:@selector(entityInManagedObjectContext:) withObject:context];
        return entity;
    }
    else
    {
        NSString *entityName = [self MR_entityName];
        return [NSEntityDescription entityForName:entityName inManagedObjectContext:context];
    }
}

where the entityInManagedObjectContext: method is not defined anywhere.

Any suggestions on how to best fix these types of errors, thanks in advance?!

Answer

newton_guima picture newton_guima · Sep 20, 2013

Yes you should.

instead of doing this:

[self.searchResults sortUsingSelector:@selector(compareByDeliveryTime:)];

you should do this:

SEL compareByDeliveryTimeSelector = sel_registerName("compareByDeliveryTime:");
[self.searchResults sortUsingSelector:compareByDeliveryTimeSelector];

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