private bool ValidateAsync(ValidationParameter validationParameter)
{
var propertyMetadata = validationParameter.PropertyMetadata;
var propertyValue = validationParameter.PropertyValue;
var validationAttributes = propertyMetadata.GetCustomAttributes(true).OfType <ValidationAttribute>().ToList();
if (validationAttributes.Any())
{
// uses the validator to check wether the property is valid or not
var validationResults = new List <ValidationResult>();
var validationContext = new ValidationContext(this, null, null);
Validator.TryValidateValue(propertyValue, validationContext, validationResults, validationAttributes);
if (validationResults.Any())
{
// adds all detected errors for this property
var errorCollection = Errors.GetOrAdd(propertyMetadata.Name, new ErrorCollection());
errorCollection.Clear();
errorCollection.AddErrors(validationResults.Select(v => v.ErrorMessage));
Errors.GetOrAdd(propertyMetadata.Name, new ErrorCollection(validationResults.Select(v => v.ErrorMessage)));
}
else
{
// reset errors for this property
ErrorCollection errorCollection;
Errors.TryRemove(propertyMetadata.Name, out errorCollection);
}
return(true);
}
return(false);
}
protected override void OnValidate(ValidationParameter validationParameter)
{
Task.Factory.StartNew(() => ValidateAsync(validationParameter))
.ContinueWith(t =>
{
if (t.Result)
{
OnRaiseErrorsChangedEvent(validationParameter.PropertyMetadata.Name);
}
},
TaskScheduler.FromCurrentSynchronizationContext());
}
public void Validate(ValidationParameter validationParameter)
{
OnValidate(validationParameter);
}
protected abstract void OnValidate(ValidationParameter validationParameter);
