diff options
author | Dennis Kobert <d-kobert@web.de> | 2019-06-11 23:38:13 +0200 |
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committer | Dennis Kobert <d-kobert@web.de> | 2019-06-11 23:38:13 +0200 |
commit | 2fa4a0e50ebfc97059c8b84dbd17e79f9afc8a8d (patch) | |
tree | c3b34ccb2737e347a73768536895cbbaab13cc01 /dsa/FireBase/ObservableExtensions.cs | |
parent | ec991104f56e90d7bb2878da2fe6ed4e585dfc46 (diff) | |
parent | af74efccf8d21e6151022b71f3cacd3fa83024ee (diff) |
Merge branch 'rework-backend'
Diffstat (limited to 'dsa/FireBase/ObservableExtensions.cs')
-rw-r--r-- | dsa/FireBase/ObservableExtensions.cs | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/dsa/FireBase/ObservableExtensions.cs b/dsa/FireBase/ObservableExtensions.cs new file mode 100644 index 0000000..bc46261 --- /dev/null +++ b/dsa/FireBase/ObservableExtensions.cs @@ -0,0 +1,40 @@ +using System; +using System.Collections.ObjectModel; +using Firebase.Database.Streaming; + +namespace Firebase.Database +{ + /// <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; + } + } +}
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