Access an objects property dynamically using a string with property name in Objective-C

Question

I have 2 objects, AddressBook and AddressCard. The AddressCard has the properties name, email, & birthday. The AddressBook has a lookup method that takes a string as an argument, and searches each added AddressCard for a match. In this lookup method I'd like to have an NSArray of each of the fields i'd like to search in the AddressCards. Then loop through each AddressBook entry test each field in my array for a match to the lookup's argument. The problem is I dont know how to access an objects property dynamically with a string - is this possible in Objective-C, or should I be trying to do this in a different way? I realize I could just use IF statements, but thats not a scalable solution.

Heres my lookup method:

-(AddressCard *)lookup:(NSString *)aName
{
    NSArray *fields = [[NSArray alloc] initWithObjects:@"name",@"email",@"birthday",nil];
    BOOL STATUS = NO;
    for(AddressCard *entry in book)
    {

        for(int i = 0; i < [fields count]; i++)
        {
            NSString *fieldName = [[NSString alloc] initWithString:[fields objectAtIndex:i]];
            NSRange range = [[entry fieldName]  rangeOfString:aName];

            if(range.location != NSNotFound)//Important to not directly test the NSRange struct, but one of its properties(BAD_ACCESS)
            {
                NSLog(@"'%@' found in field:%@ at range:%i,%i",aName,fieldName,range.location,range.length);
                STATUS = YES;
                return entry;
            }
            [n release];
        }

    }
    if(!STATUS)
        NSLog(@"'%@' not found in %@ address book",aName, bookName);

    return nil;
}

Any ideas or suggestions appreciated, thanks!

Answer 1

The method you are looking for is valueForKey:

NSRange range = [[entry valueForKey:fieldName]  rangeOfString:aName];