Proper way of using Newtonsoft Json ItemConverterType

Question

I have some bad data coming back from a web service which I cannot change. The service returns a JSON list of customers. Inside this list, each customer also has a list of jobs. But the JSON coming back is a string for the jobs.

So: Jobs: "[]" Instead of Jobs: []

So I defined the class as

[JsonProperty(PropertyName = "JOBS", ItemConverterType = typeof(StringToJobsConverter))]
public List<JobClass> Jobs { get; set; }

I created the class, and created the conversion method inside it as follows:

return JsonConvert.DeserializeObject<List<JobClass>>(existingValue.ToString());

No luck. The error retuned is Could not cast or convert from System.String to System.Collections.Generic.List`1[AppNamespace.JobClass].

Breakpoints in the converter code are never hit. Can anyone see what I'm doing wrong?

UPDATE

I found the issue but don't know how to fix. The converter is being applied to the JobClass inside the list. Not to the List itself. I want the converter applied one time only to the List deserialization. Instead it's applied to each JobClass record inside the list.

I'd strongly urge you to get them to fix their service rather than trying to implement something buggy. — mason, Jul 08 '14 at 19:06
@EZI I already specified the issue with the JSON. No need to post 30kb of data. — Paul, Jul 08 '14 at 19:18
I updated the question with additional information I've found. — Paul, Jul 08 '14 at 19:21

score 12 · Accepted Answer · answered Jul 08 '14 at 19:34

string json = @"{str1:""abc"",list:""[1,2,3]"", str2:""def""}";
var temp = JsonConvert.DeserializeObject<Temp>(json);

public class Temp
{
    public string str1;
    [JsonConverter(typeof(StringConverter<List<int>>))]
    public List<int> list;
    public string str2;
}

public class StringConverter<T> : JsonConverter
{
    public override bool CanConvert(Type objectType)
    {
        throw new NotImplementedException();
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        return JsonConvert.DeserializeObject<T>((string)reader.Value);
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        throw new NotImplementedException();
    }
}

Thank you. For anyone else who doesn't pay enough attention to attribute names, "ItemConverterType" means a converter for each item in the respected IEnumberable object. A separate JsonConverter attribute is used to convert that specific value. — Paul, Jul 08 '14 at 19:49

Proper way of using Newtonsoft Json ItemConverterType

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