From a815e4cf4c35b9a5eb8f1b43973a898acb6bf6ff Mon Sep 17 00:00:00 2001
From: Alexey Lobanov <lobanov.a@biruza.com>
Date: Fri, 29 Jul 2022 15:56:30 +0300
Subject: [PATCH] Remove FluentValidation Extension

There is a need to remove FluentValidation on ComponentBase disposed
---
 .../EditContextFluentValidationExtensions.cs  | 34 ++++++++++++++++---
 .../FluentValidationsValidator.cs             | 23 ++++++++++++-
 2 files changed, 51 insertions(+), 6 deletions(-)

diff --git a/src/Blazored.FluentValidation/EditContextFluentValidationExtensions.cs b/src/Blazored.FluentValidation/EditContextFluentValidationExtensions.cs
index c06c9f4..1326292 100644
--- a/src/Blazored.FluentValidation/EditContextFluentValidationExtensions.cs
+++ b/src/Blazored.FluentValidation/EditContextFluentValidationExtensions.cs
@@ -1,4 +1,5 @@
-using FluentValidation;
+using System.Collections.Concurrent;
+using FluentValidation;
 using FluentValidation.Internal;
 using Microsoft.AspNetCore.Components.Forms;
 using Microsoft.Extensions.DependencyInjection;
@@ -11,6 +12,8 @@ public static class EditContextFluentValidationExtensions
     private static readonly char[] Separators = { '.', '[' };
     private static readonly List<string> ScannedAssembly = new();
     private static readonly List<AssemblyScanResult> AssemblyScanResults = new();
+    private static readonly ConcurrentDictionary<EditContext, EventHandler<ValidationRequestedEventArgs>> ValidationRequestedHandlers = new();
+    private static readonly ConcurrentDictionary<EditContext, EventHandler<FieldChangedEventArgs>> FieldChangedHandlers = new();
     public const string PendingAsyncValidation = "AsyncValidationTask";
 
     public static void AddFluentValidation(this EditContext editContext, IServiceProvider serviceProvider, bool disableAssemblyScanning, IValidator? validator, FluentValidationValidator fluentValidationValidator)
@@ -19,11 +22,32 @@ public static void AddFluentValidation(this EditContext editContext, IServicePro
 
         var messages = new ValidationMessageStore(editContext);
 
-        editContext.OnValidationRequested +=
-            async (sender, _) => await ValidateModel((EditContext)sender!, messages, serviceProvider, disableAssemblyScanning, fluentValidationValidator, validator);
+        EventHandler<ValidationRequestedEventArgs> validationRequestedHandler
+            = async (sender, _) => await ValidateModel((EditContext)sender!, messages, serviceProvider, disableAssemblyScanning, fluentValidationValidator, validator);
+        if (ValidationRequestedHandlers.TryAdd(editContext, validationRequestedHandler))
+            editContext.OnValidationRequested += validationRequestedHandler;
 
-        editContext.OnFieldChanged +=
-            async (_, eventArgs) => await ValidateField(editContext, messages, eventArgs.FieldIdentifier, serviceProvider, disableAssemblyScanning, validator);
+        EventHandler<FieldChangedEventArgs> fieldChangedHandler
+            = async (_, eventArgs) => await ValidateField(editContext, messages, eventArgs.FieldIdentifier, serviceProvider, disableAssemblyScanning, validator);
+        if (FieldChangedHandlers.TryAdd(editContext, fieldChangedHandler))
+            editContext.OnFieldChanged += fieldChangedHandler;
+    }
+
+    public static void RemoveFluentValidation(this EditContext editContext)
+    {
+        ArgumentNullException.ThrowIfNull(editContext, nameof(editContext));
+
+        if (ValidationRequestedHandlers.TryGetValue(editContext, out var validationRequestedHandler))
+        {
+            editContext.OnValidationRequested -= validationRequestedHandler;
+            ValidationRequestedHandlers.TryRemove(editContext, out _);
+        }
+
+        if (FieldChangedHandlers.TryGetValue(editContext, out var fieldChangedHandler))
+        {
+            editContext.OnFieldChanged -= fieldChangedHandler;
+            FieldChangedHandlers.TryRemove(editContext, out _);
+        }
     }
 
     private static async Task ValidateModel(EditContext editContext,
diff --git a/src/Blazored.FluentValidation/FluentValidationsValidator.cs b/src/Blazored.FluentValidation/FluentValidationsValidator.cs
index ae8e6f9..c417918 100644
--- a/src/Blazored.FluentValidation/FluentValidationsValidator.cs
+++ b/src/Blazored.FluentValidation/FluentValidationsValidator.cs
@@ -7,7 +7,7 @@
 
 namespace Blazored.FluentValidation;
 
-public class FluentValidationValidator : ComponentBase
+public class FluentValidationValidator : ComponentBase, IDisposable
 {
     [Inject] private IServiceProvider ServiceProvider { get; set; } = default!;
 
@@ -81,4 +81,25 @@ protected override void OnInitialized()
 
         CurrentEditContext.AddFluentValidation(ServiceProvider, DisableAssemblyScanning, Validator, this);
     }
+
+    private bool _disposedValue;
+    protected virtual void Dispose(bool disposing)
+    {
+        if (!_disposedValue)
+        {
+            if (disposing)
+            {
+                CurrentEditContext?.RemoveFluentValidation();
+            }
+
+            _disposedValue = true;
+        }
+    }
+
+    public void Dispose()
+    {
+        // Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
+        Dispose(disposing: true);
+        GC.SuppressFinalize(this);
+    }
 }
\ No newline at end of file