Initialized service provider in validation context.

src/Framework/Framework/ViewModel/Validation/ViewModelValidator.cs

@@ -66,6 +66,8 @@ private IEnumerable<ViewModelValidationError> ValidateViewModel(object? viewMode
 
             // validate all properties on the object
             var map = viewModelSerializationMapper.GetMap(viewModel.GetType());
+            var dotvvmConfiguration = (DotvvmConfiguration)validationItems[typeof(DotvvmConfiguration)]!;
+
             foreach (var property in map.Properties.Where(p => p.TransferToServer))
             {
                 var value = property.PropertyInfo.GetValue(viewModel);
@@ -74,6 +76,7 @@ private IEnumerable<ViewModelValidationError> ValidateViewModel(object? viewMode
                 if (property.ValidationRules.Any())
                 {
                     var context = new ValidationContext(viewModel, validationItems) { MemberName = property.Name };
+                    context.InitializeServiceProvider(dotvvmConfiguration.ServiceProvider.GetService);
 
                     foreach (var rule in property.ValidationRules)
                     {
@@ -103,8 +106,11 @@ private IEnumerable<ViewModelValidationError> ValidateViewModel(object? viewMode
 
             if (viewModel is IValidatableObject)
             {
-                foreach (var error in ((IValidatableObject)viewModel).Validate(
-                    new ValidationContext(viewModel, validationItems)))
+                var validationContext = new ValidationContext(viewModel, validationItems);
+                validationContext.InitializeServiceProvider(dotvvmConfiguration.ServiceProvider.GetService);
+                var errors = ((IValidatableObject)viewModel).Validate(validationContext);
+
+                foreach (var error in errors)
                 {
                     var paths = new List<string>();
                     if (error.MemberNames != null)
@@ -114,6 +120,7 @@ private IEnumerable<ViewModelValidationError> ValidateViewModel(object? viewMode
                             paths.Add(memberPath);
                         }
                     }
+
                     if (!paths.Any())
                     {
                         paths.Add(string.Empty);

src/Tests/ViewModel/ViewModelValidatorTests.cs

@@ -446,6 +446,22 @@ public void ViewModelValidator_AttemptToPassOldPaths(string path)
         }
 
 
+        [TestMethod]
+        public void ViewModelValidator_ServiceProvider()
+        {
+            var testViewModel = new TestViewModel8();
+            var validator = CreateValidator();
+            var expander = CreateErrorPathExpander();
+            var modelState = new ModelState { ValidationTarget = testViewModel };
+
+            var errors = validator.ValidateViewModel(testViewModel).OrderBy(n => n.PropertyPath);
+            modelState.ErrorsInternal.AddRange(errors);
+            expander.Expand(modelState, testViewModel);
+            var results = modelState.Errors.OrderBy(n => n.PropertyPath).ToList();
+
+            Assert.AreEqual(0, results.Count);
+        }
+
         public class TestViewModel : DotvvmViewModelBase
         {
             [Required]
@@ -497,7 +513,7 @@ protected override ValidationResult IsValid(object value, ValidationContext vali
                 var entity = (TestViewModel4Child)validationContext.ObjectInstance;
                 if (entity.IsChecked && string.IsNullOrEmpty(entity.ConditionalRequired))
                 {
-                    return new ValidationResult("Value is required when the field is checked!", new[] { validationContext.MemberName });    
+                    return new ValidationResult("Value is required when the field is checked!", new[] { validationContext.MemberName });
                 }
 
                 return base.IsValid(value, validationContext);
@@ -542,6 +558,25 @@ public IEnumerable<ValidationResult> Validate(ValidationContext validationContex
                 }
             }
         }
-    }
 
+
+        public class TestViewModel8
+        {
+            [ServiceProviderTest]
+            public int? Id { get; set; }
+
+            public class ServiceProviderTestAttribute : ValidationAttribute
+            {
+                protected override ValidationResult IsValid(object value, ValidationContext validationContext)
+                {
+                    if (validationContext.GetService<IViewModelValidator>() == null)
+                    {
+                        return new ValidationResult("Service provider is not available");
+                    }
+
+                    return ValidationResult.Success;
+                }
+            }
+        }
+    }
 }