FluentValidation 12.0.0-preview1

FluentValidation is validation library for .NET that uses a fluent interface and lambda expressions for building strongly-typed validation rules.

Supporting the project

If you use FluentValidation in a commercial project, please sponsor the project financially. FluentValidation is developed and supported by @JeremySkinner for free in his spare time and financial sponsorship helps keep the project going. You can sponsor the project via either GitHub sponsors or OpenCollective.

Example

With FluentValidation, you can define a class that inherits from AbstractValidator which contains the rules for a particular class. The example below shows how you could define rules for a Customer class, and then how to execute the validator.

using FluentValidation;

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
  }
}

var customer = new Customer();
var validator = new CustomerValidator();

// Execute the validator.
ValidationResult results = validator.Validate(customer);

// Inspect any validation failures.
bool success = results.IsValid;
List<ValidationFailure> failures = results.Errors;

Full Documentation

Full documentation can be found at https://docs.fluentvalidation.net

Release Notes and Change Log

Release notes can be found on GitHub.

Showing the top 20 packages that depend on FluentValidation.

Packages Downloads
Nancy.Validation.FluentValidation
Adds Fluent Validation support to Nancy.
118
Nancy.Validation.FluentValidation
Adds Fluent Validation support to Nancy.
28
FluentValidation.AspNetCore
AspNetCore integration for FluentValidation
27
FluentValidation.DependencyInjectionExtensions
Dependency injection extensions for FluentValidation
26
Nancy.Validation.FluentValidation
Adds Fluent Validation support to Nancy.
17
FluentValidation.AspNetCore
AspNetCore integration for FluentValidation
16
FluentValidation.AspNetCore
AspNetCore integration for FluentValidation
15
FluentValidation.DependencyInjectionExtensions
Dependency injection extensions for FluentValidation
14
Nancy.Validation.FluentValidation
Adds Fluent Validation support to Nancy.
14
FluentValidation.AspNetCore
AspNetCore integration for FluentValidation
14

FluentValidation 12 is a major release. Please read the upgrade guide at https://docs.fluentvalidation.net/en/latest/upgrading-to-12.html Full release notes can be found at https://github.com/FluentValidation/FluentValidation/releases

.NET 8.0

  • No dependencies.

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