MediatR.Extensions.FluentValidation.AspNetCore

MediatR extension to the FluentValidation for .NET framework

Install

First you need to install packages Mediatr and FluentValidation, then follow the instructions below

Install with nuget

Install-Package MediatR.Extensions.FluentValidation.AspNetCore

Install with .NET CLI

dotnet add package MediatR.Extensions.FluentValidation.AspNetCore

How to use

Setup - Add configuration in startup

public void ConfigureServices(IServiceCollection services)
{
    // Add framework services etc.
    services.AddMvc();
    
    var domainAssembly = typeof(GenerateInvoiceHandler).GetTypeInfo().Assembly;
    // Add MediatR
    services.AddMediatR(cfg => cfg.RegisterServicesFromAssembly(domainAssembly));

    //Add FluentValidation
    services.AddFluentValidation(new[] {domainAssembly});
    
    //Add other stuffs
    ...
}

Use

Implement validator for your IRequest objects. Validation will be executed before handling IRequestHandler.

public class GenerateInvoiceValidator : AbstractValidator<GenerateInvoiceRequest>
{
    public GenerateInvoiceValidator()
    {
        RuleFor(x => x.Month).LowerThan(13);
        // etc.
    }
}

public class GenerateInvoiceRequest : IRequest
{
    public int Month { get; set; }
}
public class GenerateInvoiceRequestHandler : IRequestHandler<GenerateInvoiceRequest>
{
    public async Task Handle(GenerateInvoiceRequest request, CancellationToken cancellationToken)
    {
        // request data has been validated
        ...
    }
}

More examples check FluentValidation docs: https://fluentvalidation.net/start