Question

I trying to sort some data to use sortedArrayUsingDescriptors: method in an NSArray class.

That method must need to indicate standard comparator, but I want to indicate custom comparator what I make.

Is possible?

Here is part of my sorting code:

NSSortDescriptor *firstDescriptor =
[[[NSSortDescriptor alloc]
  initWithKey:FIRSTNAME
  ascending:YES
  selector:@selector(CustomCompare:)] autorelease];

CustomCompare: <= want to make custom comparator.

Answer 1

Why not use the sortedArrayUsingComparator: and implement your comparator to be case-insensitive? Something like this:

NSArray *sortedArray = [myArray sortedArrayUsingComparator:^(id o1, id o2) {
    NSString *str1 = (NSString *)o1;
    NSString *str2 = (NSString *)o2;

    return [str1 compare:str2 options:NSCaseInsensitiveSearch];
}];

update

For more complex classes, multiple comparison fields may also be used:

NSArray *sortedArray = [myArray sortedArrayUsingComparator:^(id o1, id o2) {
    MyClass *cl1 = (MyClass *)o1;
    MyClass *cl2 = (MyClass *)o2;

    NSComparisonResult result = [cl1.primaryString compare:cl2.primaryString options:NSCaseInsensitiveSearch];
    if (result == NSOrderedSame) {
        result = [cl1.secondaryString compare:cl2.secondaryString options:NSCaseInsensitiveSearch];        
    }
    return result;
}];