From 19eb521b37b2736dc45a1255affe01821d0dd7f5 Mon Sep 17 00:00:00 2001
From: Scott Parkhill <scott.parkhill@gmail.com>
Date: Thu, 30 Mar 2023 04:22:34 -0400
Subject: [PATCH] Catch interop undefined error instead of having application
 crash (#61)

* Fix application breaking on js interop error

Instead, it now catches the exception and stops tracking the connection.

* Change method signature for async method without await

* Remove unnecessary calls to base class initialization

* Remove unsubscription from initialization method

* Implement IDisposable and have unsubscribe occur there

* Change from OnInitializedAsync to OnIntialized
---
 .../Components/NavigationTracker.razor        |  9 +--
 .../GoogleAnalyticsStrategy.cs                | 61 ++++++++++++++++---
 2 files changed, 54 insertions(+), 16 deletions(-)

diff --git a/src/Blazor.Analytics/Components/NavigationTracker.razor b/src/Blazor.Analytics/Components/NavigationTracker.razor
index 430dbc6..73bd328 100644
--- a/src/Blazor.Analytics/Components/NavigationTracker.razor
+++ b/src/Blazor.Analytics/Components/NavigationTracker.razor
@@ -3,6 +3,8 @@
 @using Microsoft.AspNetCore.Components.Routing
 @using Blazor.Analytics.Abstractions
 
+@implements IDisposable
+
 @code
 {
     [Inject]
@@ -14,18 +16,13 @@
     [Inject]
     protected ITrackingNavigationState TrackingNavigationState { get; set; } = null;
 
-    protected override async Task OnInitializedAsync()
+    protected override void OnInitialized()
     {
-        await base.OnInitializedAsync();
-
-        NavigationManager.LocationChanged -= OnLocationChanged;
         NavigationManager.LocationChanged += OnLocationChanged;
     }
 
     protected override async Task OnAfterRenderAsync(bool firstRender)
     {
-        await base.OnAfterRenderAsync(firstRender);
-
         if (firstRender)
         {
             // Track initial navigation
diff --git a/src/Blazor.Analytics/GoogleAnalytics/GoogleAnalyticsStrategy.cs b/src/Blazor.Analytics/GoogleAnalytics/GoogleAnalyticsStrategy.cs
index ad2a17d..adab086 100644
--- a/src/Blazor.Analytics/GoogleAnalytics/GoogleAnalyticsStrategy.cs
+++ b/src/Blazor.Analytics/GoogleAnalytics/GoogleAnalyticsStrategy.cs
@@ -17,7 +17,8 @@ public sealed class GoogleAnalyticsStrategy : IAnalytics
         private Dictionary<string, object> _globalEventData = new Dictionary<string, object>();
         private bool _isInitialized = false;
         private bool _debug = false;
-
+        private bool _interopError = false;
+        
         public GoogleAnalyticsStrategy(
             IJSRuntime jsRuntime
         )
@@ -38,8 +39,16 @@ private async Task Initialize()
                 throw new InvalidOperationException("Invalid TrackingId");
             }
 
-            await _jsRuntime.InvokeAsync<string>(
-                GoogleAnalyticsInterop.Configure, _trackingId, _globalConfigData, _debug);
+            try
+            {
+                await _jsRuntime.InvokeAsync<string>(
+                    GoogleAnalyticsInterop.Configure, _trackingId, _globalConfigData, _debug);
+            }
+            catch (JSException)
+            {
+                _interopError = true;
+                Disable();
+            }
             
             _isInitialized = true;
         }
@@ -54,7 +63,7 @@ public async Task ConfigureGlobalConfigData(Dictionary<string, object> globalCon
             }
         }
 
-        public async Task ConfigureGlobalEventData(Dictionary<string, object> globalEventData)
+        public void ConfigureGlobalEventData(Dictionary<string, object> globalEventData)
         {
             this._globalEventData = globalEventData;
         }
@@ -71,8 +80,21 @@ public async Task TrackNavigation(string uri)
                 await Initialize();
             }
 
-            await _jsRuntime.InvokeAsync<string>(
-                GoogleAnalyticsInterop.Navigate, _trackingId, uri);
+            if (_interopError)
+            {
+                return;
+            }
+
+            try
+            {
+                await _jsRuntime.InvokeAsync<string>(
+                    GoogleAnalyticsInterop.Navigate, _trackingId, uri);
+            }
+            catch (JSException)
+            {
+                _interopError = true;
+                Disable();
+            }
         }
 
         public async Task TrackEvent(
@@ -106,12 +128,31 @@ public async Task TrackEvent(string eventName, object eventData)
                 await Initialize();
             }
 
-            await _jsRuntime.InvokeAsync<string>(
-                GoogleAnalyticsInterop.TrackEvent,
-                eventName, eventData, _globalEventData);
+            if (_interopError)
+            {
+                return;
+            }
+
+            try
+            {
+                await _jsRuntime.InvokeAsync<string>(
+                    GoogleAnalyticsInterop.TrackEvent,
+                    eventName, eventData, _globalEventData);
+            }
+            catch (JSException)
+            {
+                _interopError = true;
+                Disable();
+            }
         }
 
-        public void Enable() => _isGloballyEnabledTracking = true;
+        public void Enable()
+        {
+            if (_interopError) 
+                return;
+
+            _isGloballyEnabledTracking = true;
+        }
 
         public void Disable() => _isGloballyEnabledTracking = false;
     }