Question

I’m trying to implement searching for my app. If You write an exact word in the search bar, it’s ok but for example if I want to find “book” and I type in “böök”diacritics shouldn’t matter. I was using the code below but it’s not useful and also fails while searching e.g “New York – Björk”. I also tried different combinations of searchEditedText but the code became disgusting. How can I do that?

NSString *searchText = [searchBar.text capitalizedString];
NSString *searchEditedText=[searchBar.text capitalizedString];
NSMutableArray *searchArray = [[[NSMutableArray alloc] init] autorelease];
for (NSDictionary *dictionary in listOfItems) {
  NSArray *array = [dictionary objectForKey:@"Names"];
  [searchArray addObjectsFromArray:array];
}
searchEditedText = [searchEditedText stringByReplacingOccurrencesOfString:@"u" withString:@"ü"];
searchEditedText = [searchEditedText stringByReplacingOccurrencesOfString:@"c" withString:@"ç"];
searchEditedText = [searchEditedText stringByReplacingOccurrencesOfString:@"U" withString:@"Ü"];
searchEditedText = [searchEditedText stringByReplacingOccurrencesOfString:@"C" withString:@"Ç"];
searchEditedText = [searchEditedText stringByReplacingOccurrencesOfString:@"o" withString:@"ö"];
searchEditedText = [searchEditedText stringByReplacingOccurrencesOfString:@"O" withString:@"Ö"];
searchEditedText = [searchEditedText stringByReplacingOccurrencesOfString:@"g" withString:@"ğ"];
searchEditedText = [searchEditedText stringByReplacingOccurrencesOfString:@"G" withString:@"Ğ"];
searchEditedText = [searchEditedText stringByReplacingOccurrencesOfString:@"s" withString:@"ş"];
searchEditedText = [searchEditedText stringByReplacingOccurrencesOfString:@"S" withString:@"Ş"];
searchEditedText = [searchEditedText stringByReplacingOccurrencesOfString:@"i" withString:@"ı"];
searchEditedText = [searchEditedText stringByReplacingOccurrencesOfString:@"İ" withString:@"I"];
for (NSString *sTemp in searchArray) {
  NSRange titleResultsRange = [sTemp rangeOfString:searchText options:NSCaseInsensitiveSearch];
  NSRange titleResultsRange2 = [sTemp rangeOfString:searchEditedText options:NSCaseInsensitiveSearch];
  if (titleResultsRange2.length > 0 || titleResultsRange.length > 0) {
    [copyListOfItems addObject:sTemp];
  }
}

Answer 1

If you’re using Core Data, you can use an NSPredicate that searches in a case and diacritic insensitive manner. The answers in this question are performing case insensitive searches , if you add [cd] as part of the comparison e.g. contains[cd] or ==[cd], then it will perform a case and diacritic insensitive search.