RLMCollection

The number of objects in the collection.

The class name (i.e. type) of the RLMObjects contained in the collection.

The Realm which manages the collection, or nil for unmanaged collections.

Returns the object at the index specified.

Returns the first object in the collection.

Returns nil if called on an empty collection.

Returns the last object in the collection.

Returns nil if called on an empty collection.

Returns the index of an object in the collection.

Returns NSNotFound if the object is not found in the collection.

Returns the index of the first object in the collection matching the predicate.

Returns the index of the first object in the collection matching the predicate.

Returns all objects matching the given predicate in the collection.

Returns all objects matching the given predicate in the collection.

Returns a sorted RLMResults from the collection.

Returns a sorted RLMResults from the collection.

Returns an NSArray containing the results of invoking valueForKey: using key on each of the collection’s objects.

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

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

The block will be asynchronously called with the initial collection, 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 will be nil the first time the block is called. For each call after that, it will contain information about which rows in the collection were added, removed or modified. If a write transaction did not modify any objects in this collection, the block is not called at all. See the RLMCollectionChange documentation for information on how the changes are reported and an example of updating a UITableView.

If an error occurs the block will be called with nil for the collection parameter and a non-nil error. Currently the only errors that can occur are when opening the Realm on the background worker thread.

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 -[RLMRealm 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.

id<RLMCollection> collection = [Dog allObjects];
NSLog(@"dogs.count: %zu", dogs.count); // => 0
self.token = [collection addNotificationBlock:^(id<RLMCollection> dogs,
                                             RLMCollectionChange *changes,
                                             NSError *error) {
    // Only fired once for the example
    NSLog(@"dogs.count: %zu", dogs.count); // => 1
}];
[realm transactionWithBlock:^{
    Dog *dog = [[Dog alloc] init];
    dog.name = @"Rex";
    [realm addObject: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.