Json deserializer List<string>

[lukencode]

I am trying to deserialize a the json:

"types": [ "locality", "political" ]

Into a List. Attempting to do so throws - System.MissingMethodException: No parameterless constructor defined for this object.

Not sure if this is a bug or I am just doing it wrong.

[johnsheehan]

Darn, I thought this worked. It's nothing you're doing wrong. Handling for this case needs to be added.

[bkaid]

This bug seems to affect IList of any value types. I am running into the same problem serializing this array into a List: [14877833,13434092,88344083]. The result is a list of 3 longs. Also, if I serialize as a List, I get a null value.

[lukencode]

If anyone is looking for a quick and dirty fix for this issue I pieced together (read copy/paste) a deserializer based of the existing one - http://gist.github.com/485545.

Testing on it is pretty minimal but it worked for the simple stuff I used it for.

[johnsheehan]

I'm almost done with a fix for this as well. Should be committed in the next few days.

[johnsheehan]

fixed!

[bluejack2000]

Same problem exists for XML deserializer List<string>.

My hotfix for this is:

private object CreateAndMap(Type t, XElement element)
{
      object item;
      if (t == typeof(System.String))
      {
        item = element.Value;        
      }
      else
      {
        item = Activator.CreateInstance(t);
        Map(item, element);        
      }
      return item;
}

[Subv]

It still happens for user-created types, i've found a solution:

in JsonDeserializer.cs
under CreateAndMap

replace

instance = Activator.CreateInstance(type);
Map(instance, element);

with

instance = System.Runtime.Serialization.FormatterServices.GetUninitializedObject(type);
Map(instance, element);

and thats all :)