private void UnsubscribeFromNotifications(DictionaryNotificationCallbackDelegate <TValue> callback)
{
if (_keyCallbacks.Remove(callback) &&
_keyCallbacks.Count == 0)
{
UnsubscribeFromNotifications();
}
}
public IDisposable SubscribeForKeyNotifications(DictionaryNotificationCallbackDelegate <TValue> callback)
{
Argument.NotNull(callback, nameof(callback));
if (_keyCallbacks.Count == 0)
{
SubscribeForNotifications();
}
else if (_deliveredInitialKeyNotification)
{
callback(this, null, null);
}
_keyCallbacks.Add(callback);
return(NotificationToken.Create(callback, UnsubscribeFromNotifications));
}
/// <summary>
/// A convenience method that casts <see cref="IQueryable{T}"/> to <see cref="IRealmCollection{T}"/> and subscribes for change notifications.
/// </summary>
/// <param name="dictionary">The <see cref="IDictionary{String, T}"/> to observe for changes.</param>
/// <typeparam name="T">Type of the elements in the dictionary.</typeparam>
/// <seealso cref="IRealmCollection{TValue}.SubscribeForNotifications"/>
/// <param name="callback">The callback to be invoked with the updated <see cref="IRealmCollection{T}"/>.</param>
/// <returns>
/// A subscription token. It must be kept alive for as long as you want to receive change notifications.
/// To stop receiving notifications, call <see cref="IDisposable.Dispose"/>.
/// </returns>
public static IDisposable SubscribeForKeyNotifications <T>(this IDictionary <string, T> dictionary, DictionaryNotificationCallbackDelegate <T> callback)
{
Argument.NotNull(dictionary, nameof(dictionary));
if (dictionary is RealmDictionary <T> collection)
{
return(collection.SubscribeForKeyNotifications(callback));
}
throw new ArgumentException($"{nameof(dictionary)} must be an instance of IRealmCollection<KeyValuePair<string, {typeof(T).Name}>>.", nameof(dictionary));
}
