Results

A human-readable description of the objects represented by the results.

The type of the objects described by the results.

The Realm which manages this results. Note that this property will never return nil.

Indicates if the results are no longer valid.

The results becomes invalid if invalidate() is called on the containing realm. An invalidated results can be accessed, but will always be empty.

The number of objects in the results.

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

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

Returns the object at the given index.

Returns the first object in the results, or nil if the results are empty.

Returns the last object in the results, or nil if the results are empty.

Returns an Array containing the results of invoking valueForKey(_:) with key on each of the results.

Returns an Array containing the results of invoking valueForKeyPath(_:) with keyPath on each of the results.

Invokes setValue(_:forKey:) on each of the objects represented by the results using the specified value and key.

Returns a Results containing all objects matching the given predicate in the collection.

Returns a Results containing the objects represented by the results, but sorted.

Objects are sorted based on the values of the given key path. For example, to sort a collection of Students from youngest to oldest based on their age property, you might call students.sorted(byKeyPath: "age", ascending: true).

Returns a Results containing the objects represented by the results, but sorted.

Returns a Results containing distinct objects based on the specified key paths

Returns the minimum (lowest) value of the given property among all the results, or nil if the results are empty.

Returns the maximum (highest) value of the given property among all the results, or nil if the results are empty.

Returns the sum of the values of a given property over all the results.

Returns the average value of a given property over all the results, or nil if the results are empty.

Registers 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.

The change parameter that is passed to the block reports, in the form of indices within the collection, which of the objects were added, removed, or modified during each write transaction. See the RealmCollectionChange documentation for more information on the change information supplied and an example of how to use it to update a UITableView.

At the time when the block is called, the collection 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.

If no queue is given, notifications are delivered via the standard run loop, and so can’t be delivered while the run loop is blocked by other activity. If a queue is given, notifications are delivered to that queue instead. 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 dogs = realm.objects(Dog.self)
print("dogs.count: \(dogs?.count)") // => 0
let token = dogs.observe { changes 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 be sent to the block. To stop receiving updates, call invalidate() on the token.

A publisher that emits Void each time the collection changes.

Despite the name, this actually emits after the collection has changed.

Returns a RLMIterator that yields successive elements in the results.

The position of the first element in a non-empty collection. Identical to endIndex in an empty collection.

The collection’s “past the end” position. endIndex is not a valid argument to subscript, and is always reachable from startIndex by zero or more applications of successor().

Subscribe to the query represented by this Results

Subscribing to a query asks the server to synchronize all objects to the client which match the query, along with all objects which are reachable from those objects via links. This happens asynchronously, and the local client Realm may not immediately have all objects which match the query. Observe the state property of the returned subscription object to be notified of when the subscription has been processed by the server and all objects matching the query are available.

Creating a new subscription with the same name and query as an existing subscription will not create a new subscription, but instead will return an object referring to the existing sync subscription. This means that performing the same subscription twice followed by removing it once will result in no subscription existing.

By default trying to create a subscription with a name as an existing subscription with a different query or options will fail. If update is true, instead the existing subscription will be changed to use the query and options from the new subscription. This only works if the new subscription is for the same type of objects as the existing subscription, and trying to overwrite a subscription with a subscription of a different type of objects will still fail.

The number of top-level objects which are included in the subscription can optionally be limited by setting the limit paramter. If more top-level objects than the limit match the query, only the first limit objects will be included. This respects the sort and distinct order of the query being subscribed to for the determination of what the “first” objects are.

The limit does not count or apply to objects which are added indirectly due to being linked to by the objects in the subscription or due to being listed in includeLinkingObjects. If the limit is larger than the number of objects which match the query, all objects will be included.

By default subscriptions are persistent, and last until they are explicitly removed by calling unsubscribe(). Subscriptions can instead be made temporary by setting the time to live to how long the subscription should remain. After that time has elapsed the subscription will be automatically removed.

Outgoing links (i.e. List and Object properties) are automatically included in sync subscriptions. That is, if you subscribe to a query which matches one object, every object which is reachable via links from that object are also included in the subscription. By default, LinkingObjects properties do not work this way and instead, they only report objects which happen to be included in a subscription. Specific LinkingObjects properties can be explicitly included in the subscription by naming them in the includingLinkingObjects array. Any keypath which ends in a LinkingObjects property can be included in this array, including ones involving intermediate links.

Creating a subscription is an asynchronous operation and the newly created subscription will not be reported by Realm.subscriptions() until it has transitioned from the .creating state to .pending, .created or .error.