Validate MemberToCompare and original

samples/BlazorServer/Pages/Index.razor

@@ -63,6 +63,18 @@
         <ValidationMessage For="@(() => _person.Address.Postcode)" />
     </p>
 
+    <p>
+        <label>Start Lucky Number Range: </label>
+        <InputNumber @bind-Value="@_person.StartLuckyNumberRange" />
+        <ValidationMessage For="@(() => _person.StartLuckyNumberRange)" />
+    </p>
+
+    <p>
+        <label>End Lucky Number Range: </label>
+        <InputNumber @bind-Value="@_person.EndLuckyNumberRange" />
+        <ValidationMessage For="@(() => _person.EndLuckyNumberRange)" />
+    </p>
+
     <button type="submit">Save</button>
 
 </EditForm>

samples/BlazorWebAssembly/Pages/Index.razor

@@ -63,6 +63,18 @@
         <ValidationMessage For="@(() => _person.Address.Postcode)" />
     </p>
 
+    <p>
+        <label>Start Lucky Number Range: </label>
+        <InputNumber @bind-Value="@_person.StartLuckyNumberRange" />
+        <ValidationMessage For="@(() => _person.StartLuckyNumberRange)" />
+    </p>
+
+    <p>
+        <label>End Lucky Number Range: </label>
+        <InputNumber @bind-Value="@_person.EndLuckyNumberRange" />
+        <ValidationMessage For="@(() => _person.EndLuckyNumberRange)" />
+    </p>
+
     <button type="submit">Save</button>
 
 </EditForm>

samples/Shared/SharedModels/Person.cs

@@ -9,6 +9,8 @@ public class Person
         public int? Age { get; set; }
         public string? EmailAddress { get; set; }
         public Address Address { get; set; } = new();
+        public int? StartLuckyNumberRange { get; set; }
+        public int? EndLuckyNumberRange { get; set; }
     }
 
     public class PersonValidator : AbstractValidator<Person>
@@ -36,6 +38,9 @@ public PersonValidator()
                 .EmailAddress().WithMessage("You must provide a valid email address")
                 .MustAsync(async (email, _) => await IsUniqueAsync(email)).WithMessage("Email address must be unique");
 
+            RuleFor(p => p.StartLuckyNumberRange).LessThan(p => p.EndLuckyNumberRange).When(x => x.EndLuckyNumberRange.HasValue).WithMessage("Start lucky number must be less than end lucky number");
+            RuleFor(p => p.EndLuckyNumberRange).GreaterThan(p => p.StartLuckyNumberRange).When(x => x.StartLuckyNumberRange.HasValue).WithMessage("End lucky number must be greater than start lucky number");
+
             RuleFor(p => p.Address).SetValidator(new AddressValidator());
         }
 

src/Blazored.FluentValidation/EditContextFluentValidationExtensions.cs

@@ -1,7 +1,7 @@
 using FluentValidation;
 using FluentValidation.Internal;
 using FluentValidation.Results;
-
+using FluentValidation.Validators;
 using Microsoft.AspNetCore.Components.Forms;
 using Microsoft.Extensions.DependencyInjection;
 
@@ -82,15 +82,15 @@ private static async Task ValidateField(EditContext editContext,
         {
             return;
         }
-        
+
         var context = ConstructValidationContext(editContext, fluentValidationValidator);
 
         var fluentValidationValidatorSelector = context.Selector;
         var changedPropertySelector = ValidationContext<object>.CreateWithOptions(editContext.Model, strategy =>
         {
             strategy.IncludeProperties(propertyPath);
         }).Selector;
-        
+
         var compositeSelector =
             new IntersectingCompositeValidatorSelector(new[] { fluentValidationValidatorSelector, changedPropertySelector });
 
@@ -104,8 +104,39 @@ private static async Task ValidateField(EditContext editContext,
                 .Select(validationFailure => validationFailure.ErrorMessage)
                 .Distinct();
 
-            messages.Clear(fieldIdentifier);
-            messages.Add(fieldIdentifier, errorMessages);
+            var validationRules = validator as IEnumerable<IValidationRule>;
+            var members = new List<string>();
+
+            if (validationRules != null)
+            {
+                foreach (var rule in validationRules)
+                {
+                    var maybeComparison = rule.Components.FirstOrDefault()?.Validator;
+
+                    if (maybeComparison != null && maybeComparison is IComparisonValidator comparisonValidator)
+                    {
+                        var compareTo = comparisonValidator.MemberToCompare.Name;
+                        if (!members.Contains(compareTo) && rule.PropertyName == fieldIdentifier.FieldName)
+                        {
+                            members.Add(compareTo);
+                            var newProperties = members.ToList();
+                            newProperties.Add(compareTo);
+                            members = newProperties;
+                            context = new ValidationContext<object>(fieldIdentifier.Model, new PropertyChain(), new MemberNameValidatorSelector(members));
+                            validationResults = await validator.ValidateAsync(context);
+                        }
+                    }
+                    else
+                        members.Add(fieldIdentifier.FieldName);
+                }
+            }
+
+            foreach (var member in members)
+            {
+                var field = new FieldIdentifier(fieldIdentifier.Model, member);
+                messages.Clear(field);
+                messages.Add(field, validationResults.Errors.Where(x => x.PropertyName == field.FieldName).Select(error => error.ErrorMessage));
+            }
 
             editContext.NotifyValidationStateChanged();
         }