//----< write details of element with enumerable Data to string >------
public static string showElement <Key, Data, T>(this DBElement <Key, Data> elem)
where Data : IEnumerable <T> // constraint clause
{
StringBuilder accum = new StringBuilder();
accum.Append(elem.showMetaData());
if (elem.payload != null)
{
IEnumerable <object> d = elem.payload as IEnumerable <object>;
if (d == null)
{
accum.Append(String.Format("\n payload: {0}", elem.payload.ToString()));
}
else
{
bool first = true;
accum.Append(String.Format("\n payload:\n "));
foreach (var item in elem.payload) // won't compile without constraint clause
{
if (first)
{
accum.Append(String.Format(" {0}", item));
first = false;
}
else
{
accum.Append(String.Format(", {0}", item));
}
}
}
}
return(accum.ToString());
}
//----< write details of element with simple Data to string >----------
public static string showElement <Key, Data>(this DBElement <Key, Data> elem)
{
StringBuilder accum = new StringBuilder();
accum.Append(elem.showMetaData());
if (elem.payload != null)
{
accum.Append(String.Format("\n payload: {0}", elem.payload.ToString()));
}
return(accum.ToString());
}