RealmCollectionType

Element type contained in this collection.

The Realm the objects in this collection belong to, or nil if the collection’s owning object does not belong to a realm (the collection is standalone).

Returns the number of objects in this collection.

Returns a human-readable description of the objects contained in this collection.

Returns the index of the given object, or nil if the object is not in the collection.

Returns the index of the first object matching the given predicate, or nil no objects match.

Returns the index of the first object matching the given predicate, or nil if no objects match.

Returns Results containing collection elements that match the given predicate.

Returns Results containing collection elements that match the given predicate.

Returns Results containing collection elements sorted by the given property.

Returns Results with elements sorted by the given sort descriptors.

Returns the minimum value of the given property.

Returns the maximum value of the given property.

Returns the sum of the given property for objects in the collection.

Returns the average of the given property for objects in the collection.

Returns an Array containing the results of invoking valueForKey(_:) using key on each of the collection’s objects.

Returns an Array containing the results of invoking valueForKeyPath(_:) using keyPath on each of the collection’s objects.

Invokes setValue(_:forKey:) on each of the collection’s objects using the specified value and key.

Register a block to be called each time the collection changes.

The block will be asynchronously called with the initial results, and then called again after each write transaction which changes either any of the objects in the collection, or which objects are in the collection.

At the time when the block is called, the collection object will be fully evaluated and up-to-date, and as long as you do not perform a write transaction on the same thread or explicitly call realm.refresh(), accessing it will never perform blocking work.

Notifications are delivered via the standard run loop, and so can’t be delivered while the run loop is blocked by other activity. When notifications can’t be delivered instantly, multiple notifications may be coalesced into a single notification. This can include the notification with the initial collection. For example, the following code performs a write transaction immediately after adding the notification block, so there is no opportunity for the initial notification to be delivered first. As a result, the initial notification will reflect the state of the Realm after the write transaction.

let results = realm.objects(Dog)
print("dogs.count: \(dogs?.count)") // => 0
let token = dogs.addNotificationBlock { (changes: RealmCollectionChange) in
    switch changes {
        case .Initial(let dogs):
            // Will print "dogs.count: 1"
            print("dogs.count: \(dogs.count)")
            break
        case .Update:
            // Will not be hit in this example
            break
        case .Error:
            break
    }
}
try! realm.write {
    let dog = Dog()
    dog.name = "Rex"
    person.dogs.append(dog)
}
// end of run loop execution context

You must retain the returned token for as long as you want updates to continue to be sent to the block. To stop receiving updates, call stop() on the token.