diff options
author | uzvkl <dennis.kobert@student.kit.edu> | 2019-06-11 23:05:52 +0200 |
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committer | uzvkl <dennis.kobert@student.kit.edu> | 2019-06-11 23:05:52 +0200 |
commit | e6181c24124d97f2fbc932b8a68311e625463156 (patch) | |
tree | c1f097c344ca266b7941c9668590b0fd35c7870a /dsa/FireBase/ObservableExtensions.cs | |
parent | 2490ad5d31fe2ac778ff9303776f0e91f47a2862 (diff) |
Move dsa related stuff to subfolder
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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