/// <summary>
/// Gets the validation target expression.
/// </summary>
public static string GetValidationTargetExpression(DotvvmBindableObject control)
{
if (!(bool)control.GetValue(Validation.EnabledProperty))
{
return(null);
}
// find the closest control
int dataSourceChanges;
var validationTargetControl = control.GetClosestControlValidationTarget(out dataSourceChanges);
if (validationTargetControl == null)
{
return("$root");
}
// reparent the expression to work in current DataContext
var validationBindingExpression = validationTargetControl.GetValueBinding(Validation.TargetProperty);
string validationExpression = validationBindingExpression.GetKnockoutBindingExpression();
validationExpression = string.Join("", Enumerable.Range(0, dataSourceChanges).Select(i => "$parentContext.")) + validationExpression;
return(validationExpression);
}
