ViewModel

Inherit Shiny.ViewModel on your viewmodel. You will instantly gain the following:

• Features
  • Dialogs is built right in
  • Localization is built right in (you need to register it though, we will cover that in the localization section)
  • All of the Prism lifecycle stuff waiting to be used (just type override to see everything)
  • All of the Reactive setup (WhenAny, WhenAnyValue) built right in
  • Low Effort Validation

Validation

Validation is often the painful act of doing the same thing over and over and over. There are tools out there that help such as FluentValidation and Data Annotations, but nothing out of the box.

Shiny.Framework now includes optional support for DataAnnotations (with a pluggable model under IValidationService);

Data Annotations is currently the only out-of-box provider for validation. Take a look at Microsoft Data Annotations for more documentation on Data Annotations

Setup

NOTE: we recommend usage of ReactiveUI.Fody for the use of the [Reactive] attribute which removes the boilerplate code for MVVM properties

First, we need to tell Shiny.Framework to wire in the validation service to Data Annotations by doing the following in your shiny startup

public class SampleStartup : Shiny.FrameworkStartup
{
    protected override void Configure(ILoggingBuilder builder, IServiceCollection services)
    {
        services.UseDataAnnotationValidation();
    }
}

Now, in your viewmodel:

public class MyViewModel : Shiny.ViewModel
{
    [Reactive]
    [EmailAddress(ErrorMessage = "Invalid Email")]
    public string Email { get; set; }


    [Reactive]
    [MinLength(3, ErrorMessage = "Min 3 Characters")]
    [MaxLength(5, ErrorMessage = "Max 5 Characters")]
    public string LengthTest { get; set; }
}

#

Commands

public class MyViewModel : Shiny.ViewModel
{
    public MyViewModel() {
        this.Command = ReactiveCommand.Create(() => {}, this.WhenValid());
    }

    public ICommand Command { get; }

    // add some data annotated MVVM properties below
}

Localization

Data annotations actually stinks for pluggable localization. Shiny is big on pluggability so we've "hacked" our way around this one. Simply register your localization manager and follow this slight hack

We recommand creating a secondary section called Validation. Take a look at the sample app within this repo for examples.

public class MyViewModel : Shiny.ViewModel
{
    [Reactive]
    [EmailAddress(ErrorMessage = "localize:Validation:Required")]
    public string Email { get; set; }
}

NOTE: the use of "localize:" if front the localization key. Also note, that uses the fully qualified path to your localization value (ie Section:Key)