Question

I’m trying to use an NSPredicate to search for string matches against an array of CoreData objects generated like so:

// Grab an array of all Company projects
NSArray *array = [[company projects] allObjects];

I use the following predicate to match any project names, company names or client names with a case-insensitive string (note: this should allow for partial matches, so that ‘App’ will match ‘Apple Inc.’, etc):

(name LIKE[cd] %@) OR (ANY companies.name LIKE[cd] %@) OR (ANY companies.clients.name LIKE[cd] %@)

The CoreData relationships mentioned in the predicate look like so:

SELF -> (NSString *) name
SELF -> (NSSet *) companies -> (NSString *) name
SELF -> (NSSet *) companies -> (NSSet *) -> clients -> (NSString *) name

Whenever I attempt to filter by the above predicate, I find the following in my Console:

HIToolbox: ignoring exception 'Can't do regex matching on object {(
    "Apple Inc.",
"Test Co.",
Microsoft
)}.'

If I’m understanding things correctly, it looks as though trying to match against the keypath “companies.clients.name” returns an NSSet (or other object) where an NSString (name) was expected.

What am I doing wrong?

Answer 1

companies.clients.name will return collection of NSSets, where each element in the colletion is the contents of one companie’s client’s names (i.e. an NSSet). You probably want to use [e-mail] in your predicate string.

See the guide on using Set and Array Operators in Key-Value Coding.