/// <summary>
/// Can be called on a GraphTraversal to retrieve Vertices or Edges as custom objects.
/// </summary>
/// <typeparam name="T">Type of custom object that represents the Vertex or Edge</typeparam>
/// <param name="trav">Extension Object GraphTraversal</param>
/// <param name="context">Context that can store GraphElements. If you retrieved vertices and then an edge refering to those vertices they will be automatically linked.</param>
/// <returns></returns>
public static async Task <IList <T> > NextAsPOCO <T>(this GraphTraversal trav, IGraphContext context = null) // where T : new()
{
IGraphSerializer serializer = null;
List <T> result = new List <T>();
/// Verify if the OutputFormat of the GraphCommand was set to GraphSON!
Type graphTraversalType = typeof(GraphTraversal);
Type targetType = typeof(T);
FieldInfo outputFormatPropertyInfo = graphTraversalType.GetField("outputFormat", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
string outputFormat = outputFormatPropertyInfo.GetValue(trav).ToString();
if (!outputFormat.StartsWith("GraphSON"))
{
throw new Exception("OutputFormat of GraphCommand needs to be set to GRAPHSON!");
}
// GraphSerializer<T> serializer = GraphSerializerFactory.CreateGraphSerializer<T>(context);
// Edges and Vertices must be treated separately
if (GraphSerializer.GetElementType(typeof(T)) == GraphElementType.Edge)
{
List <Edge> resultSet = await trav.NextAsModelAsync <Edge>();
foreach (Edge e in resultSet)
{
string typeString = GraphSerializer.GetTypePropertyString(e, out string inVTypeString, out string outVTypeString);
if (String.IsNullOrEmpty(typeString))
{
serializer = GraphSerializerFactory.CreateGraphSerializer(context, targetType); // Try to instantiate T
}
else
{
serializer = GraphSerializerFactory.CreateGraphSerializer(context, typeString);
}
serializer.Convert(e, out object edge);
result.Add((T)edge);
}
}
else
{
List <Vertex> resultSet = await trav.NextAsModelAsync <Vertex>();
foreach (Vertex v in resultSet)
{
string typeString = GraphSerializer.GetTypePropertyString(v);
if (String.IsNullOrEmpty(typeString))
{
serializer = GraphSerializerFactory.CreateGraphSerializer(context, targetType); // Try to instantiate T
}
else
{
serializer = GraphSerializerFactory.CreateGraphSerializer(context, typeString);
}
serializer.Convert(v, out object vertex);
result.Add((T)vertex);
}
//Alternative implementation TODO: Measure speed
//==========================
//foreach (var graphSON in trav)
//{
// List<T> partialResult = serializer.DeserializeGraphSON(graphSON);
// foreach (T r in partialResult)
// result.Add(r);
//}
}
return(result);
}
