/// <summary>
/// Method that checks if bindings are correct for the validation method of this Validation rule
/// and then invokes teh validation method.
/// </summary>
/// <param name="binding"></param>
/// <returns></returns>
internal TResult Evaluate(RuleBinding <TResult> binding)
{
var bindings = MakeArgumentBindings(binding);
var result = ValidationMethod.Invoke(binding.ValidationRule, bindings);
return((TResult)result);
}
/// <summary>
/// Callback method that is called when the result of a validation rule has changed.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void ProcessValidationResult(RuleBinding <TResult> ruleBinding, TResult validationResult)
{
var rule = ruleBinding.ValidationRule;
var bindingGroups = from depBinding in ruleBinding.DependencyBindings
where
depBinding.ValidationRuleDependency.InputOnly == false &&
depBinding.TargetOwnerObject is TEntity
group depBinding by depBinding.TargetOwnerObject as TEntity;
TResult oldValidationResult = null;
if (ValidationResults.ContainsKey(ruleBinding))
{
oldValidationResult = ValidationResults[ruleBinding];
}
foreach (var bindingGroup in bindingGroups)
{
var entity = bindingGroup.Key;
var membersInError = bindingGroup.Select(binding => binding.ValidationRuleDependency.TargetProperty.Name).Distinct().ToArray();
if (HasValidationResult(entity, membersInError, oldValidationResult))
{
ClearValidationResult(entity, membersInError, oldValidationResult);
}
if (HasValidationResult(entity, membersInError, validationResult) == false)
{
SetValidationResult(entity, membersInError, validationResult);
}
}
if (IsValidationSuccess(validationResult) && oldValidationResult != null)
{
ValidationResults.Remove(ruleBinding);
if (EntitiesInErrorChanged != null)
{
EntitiesInErrorChanged(EntitiesInError, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
}
}
else
{
ValidationResults[ruleBinding] = validationResult;
if (EntitiesInErrorChanged != null)
{
EntitiesInErrorChanged(EntitiesInError, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
}
}
if (ValidationResultChanged != null)
{
ValidationResultChanged(this, new ValidationResultChangedEventArgs <TEntity, TResult>(validationResult, bindingGroups.Select(g => g.Key)));
}
}
/// <summary>
/// Returns an array of objects that form the actual parameter bindings
/// for the validation method call.
/// </summary>
/// <param name="binding"></param>
/// <returns></returns>
internal object[] MakeArgumentBindings(RuleBinding <TResult> binding)
{
var type = GetType();
if (Signature.Count != binding.DependencyBindings.Count())
{
string msg = String.Format(@"Argument count mismatch between Signature and rule method ""{0}"" in class {1}.", ValidationMethod.Name, type.Name);
throw new Exception(msg);
}
var bindings = new object[Signature.Count];
for (int i = 0; i < Signature.Count; i++)
{
var dBinding = binding.DependencyBindings[i];
bindings[i] = dBinding.ValidationRuleDependency.TargetProperty.GetValue(dBinding.TargetOwnerObject, null);
}
return(bindings);
}
