Make full validation result details available (also per field) (#212)

* Added support for accessing the full validation result on a per field basis.

* Undid the rider autoformats.

README.md

@@ -130,3 +130,31 @@ The second is when manually validating the model using the `Validate` or `Valida
         => _fluentValidationValidator?.Validate(options => options.IncludeRuleSets("Names"));
 }
 ```
+
+## Access to full `ValidationFailure`
+If you need details about the specifics of a validation result (e.g. its `Severity), you can access the result of the 
+last validation by calling the `GetFailuresFromLastValidation` method on the `FluentValidationValidator` component.
+
+```razor
+<div class="validation-message @GetValidationClass()">
+    <input type="text" @bind="@_person.Name" />
+</div>
+
+@code {
+    private FluentValidationValidator? _fluentValidationValidator;
+
+    private string GetValidationClass() 
+    {
+        var lastResult = _fluentValidationValidator?.GetFailuresFromLastValidation();
+        if (lastResult is null || !lastResult.Any())
+        {
+            return "valid";
+        }
+        if (lastResult.Any(failure => failure.Severity == Severity.Error))
+        {
+            return "invalid";
+        }
+        return "warning";
+    }
+}
+```

src/Blazored.FluentValidation/EditContextFluentValidationExtensions.cs

@@ -1,5 +1,6 @@
 using FluentValidation;
 using FluentValidation.Internal;
+using FluentValidation.Results;
 using Microsoft.AspNetCore.Components.Forms;
 using Microsoft.Extensions.DependencyInjection;
 using static FluentValidation.AssemblyScanner;
@@ -57,10 +58,21 @@ private static async Task ValidateModel(EditContext editContext,
             var validationResults = await asyncValidationTask;
 
             messages.Clear();
+            fluentValidationValidator.LastValidationResult = new Dictionary<FieldIdentifier, List<ValidationFailure>>();
+
             foreach (var validationResult in validationResults.Errors)
             {
                 var fieldIdentifier = ToFieldIdentifier(editContext, validationResult.PropertyName);
                 messages.Add(fieldIdentifier, validationResult.ErrorMessage);
+
+                if (fluentValidationValidator.LastValidationResult.TryGetValue(fieldIdentifier, out var failures))
+                {
+                    failures.Add(validationResult);
+                }
+                else
+                {
+                    fluentValidationValidator.LastValidationResult.Add(fieldIdentifier, new List<ValidationFailure> { validationResult });
+                }
             }
 
             editContext.NotifyValidationStateChanged();

src/Blazored.FluentValidation/FluentValidationsValidator.cs

@@ -17,6 +17,7 @@ public class FluentValidationValidator : ComponentBase
     [Parameter] public bool DisableAssemblyScanning { get; set; }
     [Parameter] public Action<ValidationStrategy<object>>? Options { get; set; }
     internal Action<ValidationStrategy<object>>? ValidateOptions { get; set; }
+    internal Dictionary<FieldIdentifier, List<ValidationFailure>>? LastValidationResult { get; set; }
 
     public bool Validate(Action<ValidationStrategy<object>>? options = null)
     {
@@ -81,4 +82,23 @@ protected override void OnInitialized()
 
         CurrentEditContext.AddFluentValidation(ServiceProvider, DisableAssemblyScanning, Validator, this);
     }
+
+    /// <summary>
+    /// Gets the full details of the last validation result, optionally by field.
+    /// </summary>
+    /// <param name="fieldIdentifier">If set, only returns the validation failures pertaining to the given field.</param>
+    /// <returns>Validation failures.</returns>
+    public ValidationFailure[] GetFailuresFromLastValidation(FieldIdentifier? fieldIdentifier = null)
+    {
+        if (LastValidationResult is null)
+            return Array.Empty<ValidationFailure>();
+
+        if (fieldIdentifier is null)
+            return LastValidationResult.Values.SelectMany(f => f).ToArray();
+
+        if (!LastValidationResult.TryGetValue(fieldIdentifier.Value, out var failures))
+             return Array.Empty<ValidationFailure>();
+
+        return failures.ToArray();
+    }
 }