/// <summary>
/// Reflection based recursive method to populate a type with graph node values
/// </summary>
private object ConvertGraphToTypedObject(LabelledTreeNode <object, Term> objectGraph, Type type)
{
if (objectGraph.Children.Count == 0)
{
if (type.GetTypeInfo().IsAssignableFrom(objectGraph.Value.GetType()))
{
return(objectGraph.Value);
}
else
{
throw new InvalidCastException(string.Format("Cannot cast a {0} to a {1}", objectGraph.Value.GetType(), type));
}
}
//here we use the fact that expansion types inherit from Resource
var obj = Activator.CreateInstance(type, new[] { objectGraph.Value });
foreach (var member in type.GetRuntimeProperties())
{
var memberAttribute = member.GetCustomAttribute <PropertyBindAttribute>();
if (memberAttribute != null)
{
var memberObjectGraphCollection = objectGraph.Descend(memberAttribute.Property);
if (member.PropertyType.IsListType())
{
var typedList = Activator.CreateInstance(member.PropertyType);
var addMethod = member.PropertyType.GetRuntimeMethod("Add", new Type[] { member.PropertyType.GenericTypeArguments[0] });
foreach (var memberObjectGraph in memberObjectGraphCollection)
{
addMethod.Invoke(typedList, new[] { ConvertGraphToTypedObject(memberObjectGraph, member.PropertyType.GenericTypeArguments[0]) });
}
member.SetValue(obj, typedList);
}
else
{
LabelledTreeNode <object, Term> memberObjectGraph = null;
try
{
memberObjectGraph = memberObjectGraphCollection.Single();
}
catch (Exception)
{
throw new InvalidOperationException(string.Format("The type {0} declared a non collecton property {1} but more than one node matched", type, memberAttribute.Property));
}
member.SetValue(obj, ConvertGraphToTypedObject(memberObjectGraph, member.PropertyType));
}
}
}
return(obj);
}
/// <summary>
/// Create a graph of typed objects using the type graph as a model
/// </summary>
private LabelledTreeNode <object, Term> TypifyGraph(LabelledTreeNode <object, Term> objectGraph, LabelledTreeNode <Type, Term> typeGraph)
{
var obj = ConvertGraphToTypedObject(objectGraph, typeGraph.Value);
var typedGraph = new LabelledTreeNode <object, Term>(obj);
foreach (var outEdge in typeGraph.Children)
{
var edge = outEdge.Edge;
var childTypeGraph = outEdge.TerminalNode;
var childObjectGraphs = objectGraph.Descend(edge);
foreach (var childObjectGraph in childObjectGraphs)
{
typedGraph.AddChild(edge, TypifyGraph(childObjectGraph, childTypeGraph));
}
}
return(typedGraph);
}
/// <summary>
/// Generate a bgp regex filter using the variable names in the object graph
/// </summary>
/// <param name="queryGraph">graph model of the query</param>
/// <returns></returns>
public IFilter Generate(LabelledTreeNode <object, Term> queryGraph)
{
var propertyInfo = typeof(T).GetPropertyInfo(_propertyLambda);
if (propertyInfo.Name == "Id")
{
var variable = queryGraph.Value as Variable;
return(variable != null ? new RegexFilter($"str({variable})", _regex) : null);
}
var attribute = propertyInfo.CustomAttributes.OfType <PropertyBindAttribute>().SingleOrDefault();
if (attribute != null)
{
var node = queryGraph.Descend(attribute.Property).Single();
var variable = node.Value as Variable;
return(variable != null ? new RegexFilter(variable.ToString(), _regex) : null);
}
return(null);
}
