// If an already invalid child is set or the previous child was invalid,
// the aggregated validation state of the owner changes, therefore an
// ValidationResultChanged event should be raised.
private void DetectValidationResultChange(IBehaviorContext context, Action action)
{
IViewModel oldChild = this.GetValueNext <TValue>(context);
action();
IViewModel newChild = this.GetValueNext <TValue>(context);
// It is important to query the 'oldResult' after executing the 'action'. The
// following scenario could happen otherwise:
// 1. 'oldResult' is assigned before the action and is valid.
// 2. The action is executed and makes 'oldChild' invalid and 'newChild'
// stays valid. Since 'oldChild' is still in the hierarchy at this
// time, the error is propagated to the validation caches of the
// parent.
// 3. 'newResult' is assigned to result of the 'newChild' (valid).
// 4. We would not detect a change in the 'if' below and therefore not
// raise a change which would leave the validation cache of the parents
// with the stale error.
ValidationResult oldResult = GetValidationResultOrValidIfNull(oldChild);
ValidationResult newResult = GetValidationResultOrValidIfNull(newChild);
if (!Object.Equals(oldResult, newResult))
{
context.NotifyChange(ChangeArgs.ValidationResultChanged());
}
}
public void HandleChange(IBehaviorContext context, CollectionChangedArgs <TItemVM> args)
{
var c = args.Collection;
var oldItems = (IEnumerable <IViewModel>)args.OldItems;
var newItems = (IEnumerable <IViewModel>)args.NewItems;
ChangeArgs a;
switch (args.Type)
{
// No change of 'ItemsRemoved' is raised to give the client a chance
// to distinguish if the removal was due to a repopulation (Type =
// 'Populated' and 'OldItems' contains items) or if the removal was
// triggered by a 'Clear', 'Remove' or 'SetItem'.
case CollectionChangeType.Populated:
a = ChangeArgs.CollectionPopulated(c, oldItems, args.Reason);
context.NotifyChange(a);
break;
}
switch (args.Type)
{
case CollectionChangeType.ItemRemoved:
case CollectionChangeType.ItemSet:
case CollectionChangeType.ItemsCleared:
if (args.OldItems.Any())
{
a = ChangeArgs.ItemsRemoved(c, oldItems, args.Reason);
context.NotifyChange(a);
}
break;
}
switch (args.Type)
{
case CollectionChangeType.ItemAdded:
case CollectionChangeType.ItemSet:
a = ChangeArgs.ItemsAdded(c, newItems, args.Reason);
context.NotifyChange(a);
break;
}
this.HandleChangeNext(context, args);
}
public virtual void NotifyPropertyChanged(IBehaviorContext context, ValueStage stage, TValue oldValue, TValue newValue)
{
var args = ChangeArgs.PropertyChanged(
_property, stage,
reason: null
);
context.NotifyChange(args);
this.NotifyPropertyChangedNext(context, stage, oldValue, newValue);
}
public void Refresh(IBehaviorContext context, RefreshOptions options)
{
context.NotifyChange(
ChangeArgs.PropertyChanged(
_property,
ValueStage.ValidatedValue,
RefreshReason.Create(options.ExecuteRefreshDependencies)
)
);
this.RefreshNext(context, options);
}
public override void NotifyPropertyChanged(IBehaviorContext context, ValueStage stage, TValue oldValue, TValue newValue)
{
var args = ChangeArgs.ViewModelPropertyChanged(
_property,
stage,
oldValue,
newValue,
reason: null
);
context.NotifyChange(args);
}
public void NotifyChange_CallsNotifyChangeOfViewModelWithPrependedViewModel()
{
var vm = ViewModelStub.Build();
var args = CreateChangeArgs();
IBehaviorContext kernel = CreateKernel(vm);
kernel.NotifyChange(args);
var expectedArgs = args.PrependViewModel(vm);
DomainAssert.AreEqual(expectedArgs, vm.NotifyChangeInvocations.SingleOrDefault());
}
public void UpdateValidationResult(IBehaviorContext context, ValidationResult result)
{
var previousResult = GetValidationResult(context);
if (!result.Equals(previousResult))
{
SetOrClearValidationResult(context, result);
var args = _property != null?
ChangeArgs.ValidationResultChanged(_property, _stage) :
ChangeArgs.ValidationResultChanged();
context.NotifyChange(args);
}
}
public void HandleChange(IBehaviorContext context, CollectionChangedArgs <TItemVM> args)
{
IEnumerable <TItemVM> changedItems = args
.OldItems
.Concat(args.NewItems);
IEnumerable <ValidationResult> changedItemsResults = changedItems
.Select(x => x.Kernel.GetValidationResult());
var changedItemsResult = ValidationResult.Join(changedItemsResults);
this.HandleChangeNext(context, args);
// If already invalid items are added or removed, the aggregated
// validation state of the collection owner changes, therefore an
// ValidationResultChanged event should be raised.
if (!changedItemsResult.IsValid)
{
context.NotifyChange(ChangeArgs.ValidationResultChanged(args.Reason));
}
}
public void NotifyChange_CallsParentWithExtendedPath()
{
var parentVM = ViewModelStub.Build();
var vm = ViewModelStub.Build();
var parentKernel = CreateKernel(parentVM);
var kernel = CreateKernel(vm);
kernel.Parents.Add(parentVM);
IBehaviorContext kernelContext = kernel;
var args = CreateChangeArgs();
kernelContext.NotifyChange(args);
var expectedArgs = args
.PrependViewModel(vm)
.PrependViewModel(parentVM);
DomainAssert.AreEqual(expectedArgs, parentVM.NotifyChangeInvocations.SingleOrDefault());
}
public override void InitializeValue(IBehaviorContext context)
{
base.InitializeValue(context);
TValue childVM = this.GetValueNext <TValue>(context);
if (childVM != null)
{
ValidationResult childValidatonResult = childVM
.Kernel
.GetValidationResult();
if (!childValidatonResult.IsValid)
{
// If 'PopulatedWith' returns an already invalid item, the aggregated
// validation state of the collection owner changes, therefore an
// 'ValidationResultChanged' event should be raised.
if (!childValidatonResult.IsValid)
{
context.NotifyChange(ChangeArgs.ValidationResultChanged());
}
}
}
}
public void Refresh(IBehaviorContext context, RefreshOptions options)
{
RequireInitialized();
var previousValue = GetValue(context);
RefreshCache(context);
var newValue = GetValue(context);
if (!Object.Equals(newValue, previousValue))
{
var args = ChangeArgs.ViewModelPropertyChanged(
_property,
ValueStage.ValidatedValue,
previousValue,
newValue,
RefreshReason.Create(options.ExecuteRefreshDependencies)
);
context.NotifyChange(args);
}
this.RefreshNext(context, options);
}
public void NotifyChange(ChangeArgs args)
{
Check.NotNull(args, nameof(args));
_inner.NotifyChange(args);
NotifyChangeInvocations.Add(args);
}