/// <summary>
/// Validates the given property.
/// </summary>
/// <param name="viewModel">The view model being validated.</param>
/// <param name="propertyName">The name of the property being validated.</param>
/// <returns>
/// A collection of <see cref="ValidationRuleResult"/> objects describing validation
/// failures. This does not include successful results.
/// </returns>
public IEnumerable <ValidationRuleResult> Validate(IValidatingViewModel viewModel, string propertyName)
{
IEnumerable <ValidationRuleResult> results;
if (!_results.TryGetValue(propertyName, out results))
{
results = ValidationUtilities.Validate(viewModel, propertyName).ToArray();
_results.TryAdd(propertyName, results);
}
return(results);
}
/// <summary>
/// Validates a property of a view model.
/// </summary>
/// <param name="viewModel">The view model.</param>
/// <param name="propertyName">The name of the property to validate.</param>
/// <returns>
/// A collection of <see cref="ValidationRuleResult"/> objects describing validation
/// failures. This does not include successful results.
/// </returns>
public static IEnumerable <ValidationRuleResult> Validate(
IValidatingViewModel viewModel, string propertyName)
{
IValidationRule[] rules = viewModel.Rules[propertyName].ToArray();
object value = default;
Exception getValueError = null;
if (string.IsNullOrEmpty(propertyName))
{
value = viewModel;
}
else
{
Func <object, object> getter = viewModel.GetterCache[propertyName];
try
{
value = getter(viewModel);
}
catch (Exception ex)
{
getValueError = ex;
}
}
if (getValueError is null)
{
foreach (IValidationRule rule in rules.ToArray())
{
ValidationRuleResult result;
try
{
result = rule.Run(value);
}
catch (Exception ex)
{
result = new ValidationRuleResult(true, ex.Message);
}
if (!(result is null) &&
result.IsError)
{
yield return(result);
}
}
}
else
{
yield return(new ValidationRuleResult(true, getValueError.Message));
}
}
/// <summary>
/// Validates and Messages
/// </summary>
protected bool ValidateAndMessage(IValidatingViewModel validatingViewModel, Action <IMessage> messagingAction = null)
{
var result = validatingViewModel.Validate();
if (!result.IsValid)
{
if (messagingAction != null)
{
result.Errors.ForEach(x => messagingAction(new ErrorMessage {
Text = x.ErrorMessage
}));
}
return(false);
}
return(true);
}
/// <summary>
/// Validates and forwards any error messages
/// </summary>
protected bool ValidateAndForwardMessages(IValidatingViewModel validatingViewModel)
{
return(ValidateAndMessage(validatingViewModel, this.ForwardMessage));
}
/// <summary>
/// Validates and appends any error messages
/// </summary>
protected bool ValidateAndAppendMessages(IValidatingViewModel validatingViewModel)
{
return(this.ValidateAndMessage(validatingViewModel, this.AppendMessage));
}
/// <summary>
/// Validates a model without messaging
/// </summary>
protected bool ValidateWithoutMessaging(IValidatingViewModel validatingViewModel)
{
return(this.ValidateAndMessage(validatingViewModel));
}
public IEnumerable <ValidationRuleResult> Validate(IValidatingViewModel viewModel, string propertyName)
{
return(Array.Empty <ValidationRuleResult>());
}
/// <summary>
/// Gets a collection of validation results
/// </summary>
/// <param name="viewModel">The view model whose property to validate.</param>
/// <param name="propertyName">The name of the property, or the empty string for entity rules.</param>
/// <returns>
/// A collection of <see cref="ValidationRuleResult"/> objects describing validation
/// failures. This does not include successful results.
/// </returns>
public IEnumerable <ValidationRuleResult> Validate(
IValidatingViewModel viewModel, string propertyName)
{
return(ValidationUtilities.Validate(viewModel, propertyName));
}