private void Source_ErrorsChanged(object sender, DataErrorsChangedEventArgs e)
{
if (this.validableProperties.ContainsKey(e.PropertyName))
{
var context = this.validableProperties[e.PropertyName];
var source = context.GetTarget();
if (source == null)
{
this.validableProperties.Remove(e.PropertyName);
return;
}
var errors = source.GetErrors(e.PropertyName) as IEnumerable <string>;
this.allErrors.Remove(e.PropertyName);
if (errors != null)
{
this.allErrors.Add(e.PropertyName, errors.Join("\r\n"));
}
ValidationProperties.SetHasErrors(this.AssociatedObject, this.allErrors.Count > 0);
ValidationProperties.SetErrors(this.AssociatedObject, this.allErrors.Count == 0 ? string.Empty : this.allErrors.Values.Join("\r\n\r\n"));
}
}
private void Source_Validating(object sender, ValidationEventArgs e)
{
if (!this.validableProperties.ContainsKey(e.PropertyName))
{
return;
}
var context = this.validableProperties[e.PropertyName];
var source = context.GetTarget();
if (source == null)
{
this.validableProperties.Remove(e.PropertyName);
return;
}
var property = source.GetType().GetPropertyEx(e.PropertyName);
if (property == null)
{
return;
}
var attrib = property.GetCustomAttribute <IsMandatoryAttribute>();
if (attrib == null || !attrib.IsDeactivatable)
{
return;
}
ValidationProperties.SetIsMandatory(this.AssociatedObject, attrib.IsEnabled(source, property));
}
private void SetValidationInfo(BindingExpression bindingExpression)
{
if (bindingExpression == null)
{
return;
}
// get the binding sources in order to do some voodoo on them
var source = bindingExpression.ParentBinding.Source as INotifyDataErrorInfo;
if (source == null)
{
source = this.AssociatedObject.DataContext as INotifyDataErrorInfo;
}
// we don't support too complicated binding paths
var propertyName = bindingExpression.ParentBinding.Path.Path;
// check if the property name end with a ']' ... We dont support that
if (propertyName.Right(1) == "]")
{
return;
}
if (propertyName.Contains('.'))
{
source = XAMLHelper.GetSourceFromPath(source, propertyName) as INotifyDataErrorInfo;
propertyName = propertyName.Right(propertyName.Length - propertyName.LastIndexOf('.') - 1);
}
// if our source is still null then either the source does not implements the
// INotifyDataErrorInfo interface or we dont have a valid source at all In both cases we
// just give up
if (source == null)
{
return;
}
// then let us check if the binding source have validation attributes on them
var property = source.GetType().GetPropertyEx(propertyName);
if (property == null)
{
return;
}
if (!this.validableProperties.ContainsKey(propertyName) && property.GetCustomAttributes().Any(x => x is ValidatorAttributeBase))
{
this.validableProperties.Add(propertyName, new WeakReference <INotifyDataErrorInfo>(source));
source.ErrorsChanged += this.Source_ErrorsChanged;
(source as IValidatableViewModel).IsNotNull(x => x.Validating += Source_Validating);
// Also... If we have a mandatory attribute... Add it
if (property.GetCustomAttribute <IsMandatoryAttribute>() != null)
{
ValidationProperties.SetIsMandatory(this.AssociatedObject, true);
}
}
}
