Validation.md

Validation

We use FluentValidation to execute validation rules.

Form validation

You can use the AbstractValidator to validate a form view model.

• FluentValidation is compatible with IStringLocalizer if you want to use specific resources. FluentValidation comes with default resources that can be ovewritten. This is configured in the FluentValidationLanguageManager.cs file.

• It is also compatible with GenericHost to support easy dependency injection of the validators. You can easily resolve any validators as they are registered using AddValidatorsFromAssemblyContaining in the ViewModelConfiguration.cs file.

public class LoginFormViewModel : ViewModel
{
    public LoginFormViewModel()
    {
        // This is not required but will add auto-validation when the properties change.
        this.AddValidation(this.GetProperty(x => x.Email));
        this.AddValidation(this.GetProperty(x => x.Password));
    }

    public string Email
    {
        get => this.Get<string>();
        set => this.Set(value);
    }

    public string Password
    {
        get => this.Get<string>();
        set => this.Set(value);
    }
}

// This validator is registered automatically into the IoC
public class LoginFormValidator : AbstractValidator<LoginFormViewModel>
{
    public LoginFormValidator(IStringLocalizer localizer)
    {
        RuleFor(x => x.Email).NotEmpty().WithMessage(_ => localizer["ValidationNotEmpty_Email"]).EmailAddress();
        RuleFor(x => x.Password).NotEmpty();
    }
}

// You can then validate the form by simply doing this.
// The validator will be resolved from the IoC and execute the validation on the view model.
var validationResult = await Form.Validate(ct);

Reference

• For more information on FluentValidation.