How to join two strings for NSPredicate, ie firstname and lastname - iphone

Question

I have a Person Object which has two NSString properties; firstName and lastName.
I'm currently using an NSPredicate like so:
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"(firstName contains[cd] %#) OR (lastName contains[cd] %#)", searchText, searchText];
So, for example, say I'm searching for the name "John Smith". In my search bar if I type "Joh", then John Smith will appear as an option. This is good and fine, but if I type in "John Sm" it will go blank.
How can I join firstName and lastName in the predicate so if I was searching for "John Sm" then John Smith would still appear as an option.
I hope this makes sense. Thanks.
EDIT:
To add a bit more clarification, I'm using the SearchDisplayController delegate method:
-(void)filterContentForSearchText:(NSString *)searchText scope:(NSString *)scope;
and I'm using the predicate like so:
newArray = [personObjectArray filteredArrayUsingPredicate:predicate];

Answer 1

Try this,
NSString *text = #"John Smi";
NSString *searchText = [text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
NSArray *array = [searchText componentsSeparatedByString:#" "];
NSString *firstName = searchText;
NSString *lastName = searchText;
NSPredicate *predicate = nil;
if ([array count] > 1) {
firstName = array[0];
lastName = array[1];
predicate = [NSPredicate predicateWithFormat:#"(firstName CONTAINS[cd] %# AND lastName CONTAINS[cd] %#) OR (firstName CONTAINS[cd] %# AND lastName CONTAINS[cd] %#)", firstName, lastName, lastName, firstName];
} else {
predicate = [NSPredicate predicateWithFormat:#"firstName CONTAINS[cd] %# OR lastName CONTAINS[cd] %#", firstName, lastName];
}
NSArray *filteredArray = [people filteredArrayUsingPredicate:predicate];
NSLog(#"%#", filteredArray);
Output:
(
{
firstName = John;
lastName = Smith;
}
)
Here text represents the searched text. The advantage with the above is, even if you pass text = #"Smi Joh"; or text = #"John "; or text = #" smi"; or text = #"joh smi ";, it will still show the above output.

Answer 2

The solution suggested above will not work with search strings that have more than two words. Here is a more thorough implementation in swift. This solution also allows for adding more fields on a record, if your goal is to implement a full text search across name, email, phone number, etc. In that case just update the NSPredicate to OR newField CONTAINS[cd] %# and be sure to add the extra $0 in the list of string replacements.
let searchText = search.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceCharacterSet())
let words = searchText.componentsSeparatedByCharactersInSet(NSCharacterSet.whitespaceCharacterSet())
let predicates = words.map { NSPredicate(format: "firstName CONTAINS[cd] %# OR lastName CONTAINS[cd] %#", $0,$0) }
let request = NSFetchRequest()
request.predicate = NSCompoundPredicate(type: NSCompoundPredicateType.AndPredicateType, subpredicates: predicates)

Answer 3

you can concatenate the fields into two common fields (firstLastName and lastFirstName )
- (NSString *)firstLastName {
return [NSString stringWithFormat:#"%# %#", self.firstName, self.lastName];
}
- (NSString *)lastFirstName {
return [NSString stringWithFormat:#"%# %#", self.lastName, self.firstName];
}
and then filter on this fields using 'contains[cd]'
[NSPredicate predicateWithFormat:#"(firstLastName contains[cd] %#) OR (lastFirstName contains[cd] %#)" , self.searchBar.text, self.searchBar.text];