Search and return single field of cloudkit records

Question

I have cloudKit records in the format

KeyWords : String
Content : Asset

Where the assets are approx 100k.

I'm using a SearchDisplayController to query the public database but it's returning the entire record. Every tutorial I can find does this too.

Is there a way to only return the KeyWords field eg by using predicates in a certain way?

Answer 1

OK Got something working. This may well be hacky but I put it up for info for anyone else in the same situation...

let predicate = NSPredicate(value: true) // returns all - replace with whatever condition you want
let query = CKQuery(recordType: "Library", predicate: predicate) // create a query using the predicate
var operation = CKQueryOperation(query: query) // create an operation using the query
operation.desiredKeys = ["KeyWords"] // Array of whatever 'columns' you want to return
// operation.resultsLimit = 15 // optional limit on records

// Define a closure for what to do for each returned record
operation.recordFetchedBlock = { [weak self] (record:CKRecord!) in

    // Do whatever you want with each returned record  
    println(record.objectForKey("KeyWords"))

}

// Define a closure for when the operation is complete
operation.queryCompletionBlock = { [weak self] (cursor:CKQueryCursor!, error:NSError!) in

        if cursor != nil {
            // returns the point where the operation left off if you want t retrieve the rest of the records
        }

        dispatch_async(dispatch_get_main_queue(), { () -> Void in

            // Do what you want when process complete
            self!.tableView.reloadData()
            if error != nil {
                println("there was an error")
            }
        })
    }

self.publicDatabase!.addOperation(operation) // Perform the operation on given database