SharpGrip.FluentValidation.AutoValidation.Endpoints 1.4.0

SharpGrip FluentValidation AutoValidation

Builds

Introduction

SharpGrip FluentValidation AutoValidation is an extension of the FluentValidation (v10+) library enabling automatic asynchronous validation in MVC controllers and minimal APIs (endpoints). The library FluentValidation.AspNetCore is no longer being maintained and is unsupported. As a result, support for automatic validation provided by this library is no longer available. This library re-introduces this functionality for MVC controllers and introduces automatic validation for minimal APIs (endpoints). It enables developers to easily implement automatic validation in their projects.

Installation

Register your validators with the Microsoft DI service container, for instructions on setting that up please see https://docs.fluentvalidation.net/en/latest/di.html.

MVC controllers

For MVC controllers reference NuGet package SharpGrip.FluentValidation.AutoValidation.Mvc (https://www.nuget.org/packages/SharpGrip.FluentValidation.AutoValidation.Mvc).

using SharpGrip.FluentValidation.AutoValidation.Mvc.Extensions;

builder.Services.AddFluentValidationAutoValidation();

Minimal APIs (endpoints)

For minimal APIs (endpoints) reference NuGet package SharpGrip.FluentValidation.AutoValidation.Endpoints (https://www.nuget.org/packages/SharpGrip.FluentValidation.AutoValidation.Endpoints).

Enabling minimal API (endpoint) automatic validation can be done on both route groups and routes.

using SharpGrip.FluentValidation.AutoValidation.Endpoints.Extensions;

builder.Services.AddFluentValidationAutoValidation();

var app = builder.Build();
var endpointGroup = app.MapGroup("/some-group").AddFluentValidationAutoValidation();
endpointGroup.MapPost("/", (SomeModel someModel) => $"Hello {someModel.Name}");

app.MapPost("/", (SomeOtherModel someOtherModel) => $"Hello again {someOtherModel.Name}").AddFluentValidationAutoValidation();

Configuration

MVC controllers

using SharpGrip.FluentValidation.AutoValidation.Mvc.Extensions;

builder.Services.AddFluentValidationAutoValidation(configuration =>
{
    // Disable the built-in .NET model (data annotations) validation.
    configuration.DisableBuiltInModelValidation = true;

    // Only validate controllers decorated with the `FluentValidationAutoValidation` attribute.
    configuration.ValidationStrategy = ValidationStrategy.Annotation;

    // Enable validation for parameters bound from `BindingSource.Body` binding sources.
    configuration.EnableBodyBindingSourceAutomaticValidation = true;

    // Enable validation for parameters bound from `BindingSource.Form` binding sources.
    configuration.EnableFormBindingSourceAutomaticValidation = true;

    // Enable validation for parameters bound from `BindingSource.Query` binding sources.
    configuration.EnableQueryBindingSourceAutomaticValidation = true;

    // Enable validation for parameters bound from `BindingSource.Path` binding sources.
    configuration.EnablePathBindingSourceAutomaticValidation = true;

    // Enable validation for parameters bound from 'BindingSource.Custom' binding sources.
    configuration.EnableCustomBindingSourceAutomaticValidation = true;

    // Replace the default result factory with a custom implementation.
    configuration.OverrideDefaultResultFactoryWith<CustomResultFactory>();
});

public class CustomResultFactory : IFluentValidationAutoValidationResultFactory
{
    public IActionResult CreateActionResult(ActionExecutingContext context, ValidationProblemDetails? validationProblemDetails)
    {
        return new BadRequestObjectResult(new {Title = "Validation errors", ValidationErrors = validationProblemDetails?.Errors});
    }
}

Minimal APIs (endpoints)

using SharpGrip.FluentValidation.AutoValidation.Endpoints.Extensions;

builder.Services.AddFluentValidationAutoValidation(configuration =>
{
    // Replace the default result factory with a custom implementation.
    configuration.OverrideDefaultResultFactoryWith<CustomResultFactory>();
});

public class CustomResultFactory : IFluentValidationAutoValidationResultFactory
{
    public IResult CreateResult(EndpointFilterInvocationContext context, ValidationResult validationResult)
    {
        var validationProblemErrors = validationResult.ToValidationProblemErrors();

        return Results.ValidationProblem(validationProblemErrors, "Some details text.", "Some instance text.", (int) HttpStatusCode.BadRequest, "Some title.");
    }
}

Validation attributes

MVC controllers

Customizing automatic validation behavior is achievable through the use of attributes.

The [AutoValidateAlways] attribute can be applied to a controller parameter, compelling automatic validation to disregard the validation check for a valid binding source. This proves useful when the ApiBehaviorOptions.SuppressInferBindingSourcesForParameters option is enabled, and a custom model is used, with parameters bound from multiple binding sources.

The [AutoValidateNever] attribute can be placed on a controller class, controller method, or controller parameter, instructing automatic validation to be skipped.

Validation interceptors

Note: Using validation interceptors is considered to be an advanced feature and is not needed for most use cases.

Validation interceptors allow you to intercept and alter the validation process by either implementing the IGlobalValidationInterceptor interface in a custom class or by implementing the IValidatorInterceptor on a single validator. During the validation process both instances get resolved and called (if they are present) creating a mini pipeline of validation interceptors:

==> IValidatorInterceptor.BeforeValidation()
==> IGlobalValidationInterceptor.BeforeValidation()

Validation

==> IValidatorInterceptor.AfterValidation()
==> IGlobalValidationInterceptor.AfterValidation()

Both interfaces define a BeforeValidation and a AfterValidation method.

The BeforeValidation method gets called before validation and allows you to return a custom IValidationContext which gets passed to the validator. In case you return null the default IValidationContext will be passed to the validator.

The AfterValidation method gets called after validation and allows you to return a custom IValidationResult which gets passed to the IFluentValidationAutoValidationResultFactory. In case you return null the default IValidationResult will be passed to the IFluentValidationAutoValidationResultFactory.

MVC controllers

// Example of a global validation interceptor.
builder.Services.AddTransient<IGlobalValidationInterceptor, CustomGlobalValidationInterceptor>();

public class CustomGlobalValidationInterceptor : IGlobalValidationInterceptor
{
    public IValidationContext? BeforeValidation(ActionExecutingContext actionExecutingContext, IValidationContext validationContext)
    {
        // Return a custom `IValidationContext` or null.
        return null;
    }

    public ValidationResult? AfterValidation(ActionExecutingContext actionExecutingContext, IValidationContext validationContext)
    {
        // Return a custom `ValidationResult` or null.
        return null;
    }
}

// Example of a single validator interceptor.
private class TestValidator : AbstractValidator<TestModel>, IValidatorInterceptor
{
    public TestValidator()
    {
        RuleFor(x => x.Parameter1).Empty();
        RuleFor(x => x.Parameter2).Empty();
        RuleFor(x => x.Parameter3).Empty();
    }

    public IValidationContext? BeforeValidation(ActionExecutingContext actionExecutingContext, IValidationContext validationContext)
    {
        // Return a custom `IValidationContext` or null.
        return null;
    }

    public ValidationResult? AfterValidation(ActionExecutingContext actionExecutingContext, IValidationContext validationContext)
    {
        // Return a custom `ValidationResult` or null.
        return null;
    }
}

Minimal APIs (endpoints)

// Example of a global validation interceptor.
builder.Services.AddTransient<IGlobalValidationInterceptor, CustomGlobalValidationInterceptor>();

public class CustomGlobalValidationInterceptor : IValidationInterceptor
{
    public IValidationContext? BeforeValidation(EndpointFilterInvocationContext endpointFilterInvocationContext, IValidationContext validationContext)
    {
        // Return a custom `IValidationContext` or null.
        return null;
    }

    public ValidationResult? AfterValidation(EndpointFilterInvocationContext endpointFilterInvocationContext, IValidationContext validationContext)
    {
        // Return a custom `ValidationResult` or null.
        return null;
    }
}

// Example of a single validator interceptor.
private class TestValidator : AbstractValidator<TestModel>, IValidatorInterceptor
{
    public TestValidator()
    {
        RuleFor(x => x.Parameter1).Empty();
        RuleFor(x => x.Parameter2).Empty();
        RuleFor(x => x.Parameter3).Empty();
    }

    public IValidationContext? BeforeValidation(EndpointFilterInvocationContext endpointFilterInvocationContext, IValidationContext validationContext)
    {
        // Return a custom `IValidationContext` or null.
        return null;
    }

    public ValidationResult? AfterValidation(EndpointFilterInvocationContext endpointFilterInvocationContext, IValidationContext validationContext)
    {
        // Return a custom `ValidationResult` or null.
        return null;
    }
}