public void ShouldDeliverErrorsWhenModelObservableValidationTriggers()
{
var viewModel = new IndeiTestViewModel();
string namesShouldMatchMessage = "names should match.";
var validation = new ModelObservableValidation <IndeiTestViewModel, string>(
viewModel,
vm => vm.OtherName,
vm => vm.WhenAnyValue(
m => m.Name,
m => m.OtherName,
(n, on) => new { n, on })
.Select(bothNames => bothNames.n == bothNames.on),
(_, isValid) => isValid ? string.Empty : namesShouldMatchMessage);
viewModel.ValidationContext.Add(validation);
Assert.False(viewModel.HasErrors);
Assert.True(viewModel.ValidationContext.IsValid);
Assert.Single(viewModel.ValidationContext.Validations);
Assert.Empty(viewModel.GetErrors(nameof(viewModel.Name)).Cast <string>());
Assert.Empty(viewModel.GetErrors(nameof(viewModel.OtherName)).Cast <string>());
viewModel.Name = "JoJo";
viewModel.OtherName = "NoNo";
Assert.True(viewModel.HasErrors);
Assert.Empty(viewModel.GetErrors(nameof(viewModel.Name)).Cast <string>());
Assert.Single(viewModel.GetErrors(nameof(viewModel.OtherName)).Cast <string>());
Assert.Single(validation.Text);
Assert.Equal(namesShouldMatchMessage, validation.Text.Single());
}
/// <summary>
/// Setup a validation rule with a general observable indicating validity.
/// </summary>
/// <typeparam name="TViewModel">ViewModel type.</typeparam>
/// <typeparam name="TViewModelProp">ViewModel property type.</typeparam>
/// <param name="viewModel">ViewModel instance.</param>
/// <param name="viewModelProperty">ViewModel property referenced in viewModelObservableProperty.</param>
/// <param name="viewModelObservableProperty">Func to define if the viewModel is valid or not.</param>
/// <param name="messageFunc">Func to define the validation error message based on the viewModel and viewModelObservableProperty values.</param>
/// <returns>Returns a <see cref="ValidationHelper"/> object.</returns>
/// <remarks>
/// It should be noted that the observable should provide an initial value, otherwise that can result
/// in an inconsistent performance.
/// </remarks>
public static ValidationHelper ValidationRule <TViewModel, TViewModelProp>(
this TViewModel viewModel,
Expression <Func <TViewModel, TViewModelProp> > viewModelProperty,
Func <TViewModel, IObservable <bool> > viewModelObservableProperty,
Func <TViewModel, bool, string> messageFunc)
where TViewModel : ReactiveObject, IValidatableViewModel
{
if (viewModel is null)
{
throw new ArgumentNullException(nameof(viewModel));
}
if (viewModelProperty is null)
{
throw new ArgumentNullException(nameof(viewModelProperty));
}
if (viewModelObservableProperty is null)
{
throw new ArgumentNullException(nameof(viewModelObservableProperty));
}
if (messageFunc is null)
{
throw new ArgumentNullException(nameof(messageFunc));
}
var validation = new ModelObservableValidation <TViewModel, TViewModelProp>(viewModel, viewModelProperty, viewModelObservableProperty, messageFunc);
viewModel.ValidationContext.Add(validation);
return(new ValidationHelper(validation));
}
/// <summary>
/// Setup a validation rule with a general observable indicating validity.
/// </summary>
/// <typeparam name="TViewModel">ViewModel type.</typeparam>
/// <param name="viewModel">ViewModel instance.</param>
/// <param name="viewModelObservableProperty">Func to define if the viewModel is valid or not.</param>
/// <param name="messageFunc">Func to define the validation error message based on the viewModel and viewModelObservableProperty values.</param>
/// <returns>Returns a <see cref="ValidationHelper"/> object.</returns>
/// <remarks>
/// It should be noted that the observable should provide an initial value, otherwise that can result
/// in an inconsistent performance.
/// </remarks>
public static ValidationHelper ValidationRule <TViewModel>(
this TViewModel viewModel,
Func <TViewModel, IObservable <bool> > viewModelObservableProperty,
Func <TViewModel, bool, string> messageFunc)
where TViewModel : ReactiveObject, ISupportsValidation
{
var validation =
new ModelObservableValidation <TViewModel>(viewModel, viewModelObservableProperty, messageFunc);
viewModel.ValidationContext.Add(validation);
return(new ValidationHelper(validation));
}
public void InitialValidStateIsCorrect()
{
var model = new TestViewModel()
{
Name = "name", Name2 = "name2"
};
Subject <bool> validState = new Subject <bool>();
var v = new ModelObservableValidation <TestViewModel>(model, (m) => validState.StartWith(true), (m, s) => "broken");
Assert.True(v.IsValid);
}
public void ObservableToInvalid()
{
var model = new TestViewModel()
{
Name = "name", Name2 = "name2"
};
ReplaySubject <bool> validState = new ReplaySubject <bool>(1);
var v = new ModelObservableValidation <TestViewModel>(model, (m) => validState, (m, s) => "broken");
validState.OnNext(false);
validState.OnNext(true);
validState.OnNext(false);
Assert.False(v.IsValid);
Assert.Equal("broken", v.Text.ToSingleLine());
}
