.. FluentValidation documentation master file, created by sphinx-quickstart on Wed Feb 5 15:31:13 2020. You can adapt this file completely to your liking, but it should at least contain the root toctree directive.

FluentValidation

FluentValidation is a .NET library for building strongly-typed validation rules.

FluentValidation 12 supports .NET 8 and newer (including .NET 10)

If you need support for older runtimes, use FluentValidation 11 which runs on .NET Standard 2.0, .NET Core 3.1, .NET 5 and newer.

If you're moving from FluentValidation 11 to 12 please review the :doc:upgrading-to-12

If you're new to using FluentValidation, check out the :doc:start page.

.. note:: If you use FluentValidation in a commercial project, please sponsor the project financially <https://github.com/sponsors/JeremySkinner>. FluentValidation is developed for free by @JeremySkinner <https://github.com/JeremySkinner> in his spare time and financial sponsorship helps keep the project going. Please sponsor the project via either GitHub sponsors <https://github.com/sponsors/JeremySkinner>_ or OpenCollective <https://opencollective.com/FluentValidation>_.

Example

.. code-block:: c#

public class CustomerValidator : AbstractValidator<Customer> { public CustomerValidator() { RuleFor(x => x.Surname).NotEmpty(); RuleFor(x => x.Forename).NotEmpty().WithMessage("Please specify a first name"); RuleFor(x => x.Discount).NotEqual(0).When(x => x.HasDiscount); RuleFor(x => x.Address).Length(20, 250); RuleFor(x => x.Postcode).Must(BeAValidPostcode).WithMessage("Please specify a valid postcode"); }

 private bool BeAValidPostcode(string postcode) 
 {
   // custom postcode validating logic goes here
 }

}

.. _user-docs: .. toctree:: :maxdepth: 1 :caption: Getting Started

installation start collections

.. _config-docs: .. toctree:: :maxdepth: 1 :caption: Configuring Validators

configuring conditions

.. _validator-docs: .. toctree:: :maxdepth: 1 :caption: Building Rules

built-in-validators custom-validators

.. _feature-docs: .. toctree:: :maxdepth: 1 :caption: Other Features

including-rules specific-properties rulesets cascade di async severity error-codes custom-state

.. _localization-docs: .. toctree:: :maxdepth: 1 :caption: Localization

localization

.. _testing-docs: .. toctree:: :maxdepth: 1 :caption: Testing

testing

.. _advanced-docs: .. toctree:: :maxdepth: 1 :caption: Advanced

dependentrules inheritance advanced

.. _aspnet-docs: .. toctree:: :maxdepth: 1 :caption: ASP.NET Integration

aspnet blazor

.. _upgrading-docs: .. toctree:: :maxdepth: 1 :caption: Upgrading

upgrading-to-12 upgrading-to-11 upgrading-to-10 upgrading-to-9 upgrading-to-8