/// <summary>
/// Sets the known validation errors for a property.
/// This may produce a prompt in the UI to correct
/// the error before proceeding.
/// </summary>
/// <param name="propertyName">Name of the property.</param>
/// <param name="dataErrors">The data errors.</param>
public void SetPropertyErrors(
string propertyName, IEnumerable <DataValidationError> dataErrors)
{
AssertArg.IsNotNullOrEmpty(propertyName, nameof(propertyName));
bool raiseEvent = false;
lock (errorsLock)
{
bool created = false;
var errorsArray = dataErrors as DataValidationError[] ?? dataErrors?.ToArray();
int paramErrorCount = errorsArray?.Length ?? 0;
if ((errorsField == null || errorsField.Count < 1) &&
paramErrorCount < 1)
{
return;
}
if (errorsField == null)
{
errorsField = new Dictionary <string, ObservableCollection <DataValidationError> >();
created = true;
}
bool listFound = false;
if (created || !(listFound = errorsField.TryGetValue(propertyName,
out ObservableCollection <DataValidationError> list)))
{
list = new ObservableCollection <DataValidationError>();
}
if (paramErrorCount < 1)
{
if (listFound)
{
list?.Clear();
raiseEvent = true;
}
}
else
{
var tempList = new List <DataValidationError>();
if (errorsArray != null)
{
foreach (var dataError in errorsArray)
{
if (created || list.SingleOrDefault(
e => e.Id == dataError.Id) == null)
{
tempList.Add(dataError);
raiseEvent = true;
}
}
}
list.AddRange(tempList);
errorsField[propertyName] = list;
}
}
if (raiseEvent)
{
OnErrorsChanged(propertyName);
}
}