From 278adce7226023c7b0fb040faf89282cffc5b726 Mon Sep 17 00:00:00 2001
From: Michal Rousal <michalr@microsoft.com>
Date: Fri, 2 Mar 2018 15:44:21 +0100
Subject: [PATCH] add onError event and wire image load failure to it

---
 .../Views/Image/ReactImageLoadEvent.cs        | 30 ++++++++++++++++-
 .../Views/Image/ReactImageManager.cs          | 32 +++++++++++++------
 2 files changed, 52 insertions(+), 10 deletions(-)

diff --git a/ReactWindows/ReactNative.Shared/Views/Image/ReactImageLoadEvent.cs b/ReactWindows/ReactNative.Shared/Views/Image/ReactImageLoadEvent.cs
index 21c82193875..cccbff5bc7b 100644
--- a/ReactWindows/ReactNative.Shared/Views/Image/ReactImageLoadEvent.cs
+++ b/ReactWindows/ReactNative.Shared/Views/Image/ReactImageLoadEvent.cs
@@ -25,10 +25,16 @@ public class ReactImageLoadEvent : Event
         /// </summary>
         public const int OnLoadEnd = 3;
 
+        /// <summary>
+        /// The event identifier for image load error.
+        /// </summary>
+        public const int OnError = 4;
+
         private readonly int _eventType;
         private readonly string _imageUri;
         private readonly int _width;
         private readonly int _height;
+        private readonly string _error;
 
         /// <summary>
         /// Instantiates a <see cref="ReactImageLoadEvent"/>.
@@ -57,6 +63,18 @@ public ReactImageLoadEvent(int viewId, int eventType, string imageUri, int width
             _height = height;
         }
 
+        /// <summary>
+        /// Instantiates a <see cref="ReactImageLoadEvent"/>.
+        /// </summary>
+        /// <param name="viewId">The view identifier.</param>
+        /// <param name="error">The error string.</param>
+        public ReactImageLoadEvent(int viewId, string error)
+            : base(viewId)
+        {
+            _eventType = OnError;
+            _error = error;
+        }
+
         /// <summary>
         /// The name of the event.
         /// </summary>
@@ -72,6 +90,8 @@ public override string EventName
                         return "topLoad";
                     case OnLoadEnd:
                         return "topLoadEnd";
+                    case OnError:
+                        return "topError";
                     default:
                         throw new InvalidOperationException(
                             Invariant($"Invalid image event '{_eventType}'."));
@@ -135,7 +155,15 @@ public override void Dispatch(RCTEventEmitter eventEmitter)
                 }
             }
 
+            if (_eventType == OnError)
+            {
+                eventData = new JObject()
+                {
+                    { "error", _error }
+                };
+            }
+
             eventEmitter.receiveEvent(ViewTag, EventName, eventData);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/ReactWindows/ReactNative/Views/Image/ReactImageManager.cs b/ReactWindows/ReactNative/Views/Image/ReactImageManager.cs
index 394d2707a63..d12aa31482c 100644
--- a/ReactWindows/ReactNative/Views/Image/ReactImageManager.cs
+++ b/ReactWindows/ReactNative/Views/Image/ReactImageManager.cs
@@ -64,6 +64,13 @@ public override IReadOnlyDictionary<string, object> ExportedCustomDirectEventTyp
                             { "registrationName", "onLoadEnd" }
                         }
                     },
+                    {
+                        "topError",
+                        new Dictionary<string, object>
+                        {
+                            { "registrationName", "onError" }
+                        }
+                    },
                 };
             }
         }
@@ -234,7 +241,7 @@ public override void SetDimensions(Border view, Dimensions dimensions)
             SetUriFromMultipleSources(view);
         }
 
-        private void OnImageFailed(Border view)
+        private void OnImageFailed(Border view, Exception e)
         {
             if (!view.HasTag())
             {
@@ -242,13 +249,20 @@ private void OnImageFailed(Border view)
                 return;
             }
 
-            view.GetReactContext()
+            var eventDispatcher = view.GetReactContext()
                 .GetNativeModule<UIManagerModule>()
-                .EventDispatcher
-                .DispatchEvent(
-                    new ReactImageLoadEvent(
-                        view.GetTag(),
-                        ReactImageLoadEvent.OnLoadEnd));
+                .EventDispatcher;
+
+            eventDispatcher.DispatchEvent(
+                new ReactImageLoadEvent(
+                    view.GetTag(),
+                    e.Message));
+
+            eventDispatcher.DispatchEvent(
+                new ReactImageLoadEvent(
+                    view.GetTag(),
+                    ReactImageLoadEvent.OnLoadEnd));
+
         }
 
         private void OnImageStatusUpdate(Border view, ImageLoadStatus status, ImageMetadata metadata)
@@ -290,9 +304,9 @@ private async void SetUriFromSingleSource(Border view, string source)
                 imageBrush.ImageSource = image;
                 OnImageStatusUpdate(view, ImageLoadStatus.OnLoadEnd, metadata);
             }
-            catch
+            catch (Exception e)
             {
-                OnImageFailed(view);
+                OnImageFailed(view, e);
             }
         }