Search Contacts via group using CNContact

Question

Using Swift2 I am trying to find all contacts that are members of the "Work" group and just return those contacts.

After creating the predicate.

let workPred = CNContact.predicateForContactsInGroupWithIdentifier("Work")
let keysToFetch = [CNContactGivenNameKey]
let results = contacts.unifiedContactsMatchingPredicate(workPred, keysToFetch)

However it always returns 0 results when there are contacts of the group id.

Answer 1

"Work" is not group identifier. You have to fetch groups via CNContactStore's groupsMatchingPredicate:

• func groupsMatchingPredicate(_ predicate: NSPredicate?) throws -> [CNGroup]

Then you'll get an array of CNGroup objects. Every CNGroup has two properties:

• name and
• identifier.

So CNGroup.identifier is what you want to use in your predicate. An example of CNGroup objects:

[
  <CNGroup: 0x7fe563ca91f0: identifier=2DFE28EB-A9CA-4920-A77D-46BEE5A09E96, name=Friends>,
  <CNGroup: 0x7fe563ca3bc0: identifier=E007B6DD-F456-48FA-A564-32256A898B67, name=Work>
]

Here you can see that the identifier is generated UUID. Not the group name.

Here's an example:

do {
  let store = CNContactStore()

  let groups = try store.groupsMatchingPredicate(nil)
  let filteredGroups = groups.filter { $0.name == "Work" }

  guard let workGroup = filteredGroups.first else {
    print("No Work group")
    return
  }

  let predicate = CNContact.predicateForContactsInGroupWithIdentifier(workGroup.identifier)
  let keysToFetch = [CNContactGivenNameKey]
  let contacts = try store.unifiedContactsMatchingPredicate(predicate, keysToFetch: keysToFetch)

  print(contacts)
}
catch {
  print("Handle error")
}

Didn't find any suitable predicate (on CNGroup) to match group name directly.