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Diffstat (limited to 'FireBase/ObservableExtensions.cs')
-rw-r--r-- | FireBase/ObservableExtensions.cs | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/FireBase/ObservableExtensions.cs b/FireBase/ObservableExtensions.cs new file mode 100644 index 0000000..37c3ef7 --- /dev/null +++ b/FireBase/ObservableExtensions.cs @@ -0,0 +1,44 @@ +namespace Firebase.Database +{ + using System; + using System.Collections.ObjectModel; + + using Firebase.Database.Streaming; + + /// <summary> + /// Extensions for <see cref="IObservable{T}"/>. + /// </summary> + public static class ObservableExtensions + { + /// <summary> + /// Starts observing on given firebase observable and propagates event into an <see cref="ObservableCollection{T}"/>. + /// </summary> + /// <param name="observable"> The observable. </param> + /// <typeparam name="T"> Type of entity. </typeparam> + /// <returns> The <see cref="ObservableCollection{T}"/>. </returns> + public static ObservableCollection<T> AsObservableCollection<T>(this IObservable<FirebaseEvent<T>> observable) + { + var collection = new ObservableCollection<T>(); + + observable.Subscribe(f => + { + if (f.EventType == FirebaseEventType.InsertOrUpdate) + { + var i = collection.IndexOf(f.Object); + if (i >= 0) + { + collection.RemoveAt(i); + } + + collection.Add(f.Object); + } + else + { + collection.Remove(f.Object); + } + }); + + return collection; + } + } +} |