Deserialize SimpleCollectionRepresentation fails (HAL+XML format only)

[Sebastien34]

Hi,
I'm using WebApi.Hal in both server and client sides of my API.
On the client side, when deserializing SimpleListRepresentation<> in 'HAL+XML', ResourceList collection remains empty. This works fine with HAL+JSON.
I drilled down into the source code to try to spot in the problem and discovered that the issue is located in XmlHalMEdiaTypeFormatter.cs / object ReadHalResource(Type type, XElement xml) method when dealing with collections.

First issue :
the test
if (typeof(IRepresentationList).IsAssignableFrom(type))
is never true when the resource is of type SimpleListRepresentation.

Second issue :
the line
var genericTypeArg = type.GetGenericArguments().Single();
throws an exception because the class that inherits from SimpleListCollection<> isn't itself generic. The generic type should be infered from the base class.

Proposed patch (XmlHalMediaTypeFormatter.cs line 66 - 2 lines changed):
static object ReadHalResource(Type type, XElement xml)
{
Representation representation;

        if (xml == null)
        {
            return null;
        }

        // First, determine if Resource of type Generic List and construct Instance with respective Parameters

        //if (typeof(IRepresentationList).IsAssignableFrom(type))   
        if (type.BaseType.Name == "SimpleListRepresentation`1")     //patch : SimpleListRepresentation isn't an IRepresentationList. My patch is ugly there must be a smarter way to do this check
        {
            var resourceListXml = xml.Elements("resource");  // .Where(x => x.Attribute("rel").Value == "item");
            //var genericTypeArg = type.GetGenericArguments().Single(); 
            var genericTypeArg = type.BaseType.GetGenericArguments().Single();      //patch : use the base class to infer generic argument
            var resourceList = (IList)Activator.CreateInstance(typeof(List<>).MakeGenericType(genericTypeArg));

            foreach (var resourceListItem in resourceListXml.Select(resourceXml => ReadHalResource(genericTypeArg, resourceXml)))
            {
                resourceList.Add(resourceListItem);
            }

As mentioned, I'm not happy with the check, there must be a cleaner way to achieve that, but it works...

Hope this helps and thanks for you work.

Regards
/Sebastien

[panmanphil]

closing stale issue