C# Json To Dictionary of Objects

Question

I want to take some Json and parse it in to a collection of key/value pairs, but some of the values will be dictionaries themselves. I tried the usual Newtonsoft deserialization. It's close, but not quite right. The end result must be a dictionary, not a strongly typed class.

This is some example Json:

{
  "JobNumber": 1010,
  "Asset": null,
  "JobNotes": [
    {
      "NoteText": "It's not working.",
      "NoteType": "Complaint"
    },
    {
      "NoteText": "Needs to be fixed",
      "NoteType": "Job"
    }
  ]
}

This is the code I used to deserialize:

        var json = File.ReadAllText(@"c:\temp\job.json");
        var result = JsonConvert.DeserializeObject<Dictionary<string, object>>(json);

The result is almost correct, but the value of the item with a key of "JobNotes" is just json string. I want the parser to recurse in and deserialise the inner Json to a further dictionary of strings and objects. Is there a way I can do this with the Newtonsoft library? Or, is there another library that will do the trick? Can I hook in to the parsing method to override the functionality at that point in time?

Answer 1

This is a modified version of @DanielKeogh's code. It works well.

class Program
{
    static void Main(string[] args)
    {
        var json = File.ReadAllText(@"c:\temp\job3.json");
        var result = JsonConvert.DeserializeObject<Dictionary<string, object>>(json);
        RecurseDeserialize(result);
    }

    private static void RecurseDeserialize(Dictionary<string, object> result)
    {
        //Iterate throgh key/value pairs
        foreach (var keyValuePair in result.ToArray())
        {
            //Check to see if Newtonsoft thinks this is a JArray
            var jarray = keyValuePair.Value as JArray;

            if (jarray != null)
            {
                //We have a JArray

                //Convert JArray back to json and deserialize to a list of dictionaries
                var dictionaries = JsonConvert.DeserializeObject<List<Dictionary<string, object>>>(jarray.ToString()); 

                //Set the result as the dictionary
                result[keyValuePair.Key] = dictionaries;

                //Iterate throught the dictionaries
                foreach (var dictionary in dictionaries)
                {
                    //Recurse
                    RecurseDeserialize(dictionary);
                }
            }
        }
    }
}

This modified Json shows how deep it goes:

{
  "JobNumber": 1010,
  "Asset": null,
  "JobNotes": [
    {
      "NoteText": "It's not working.",
      "NoteType": "Complaint"
    },
    {
      "NoteText": "Needs to be fixed",
      "NoteType": "Job",
      "JobNoteNotes": [
        {
          "Something": 1,
          "Something2": "Test"
        }
      ]
    }
  ]
}

The result ends three dictionaries deep so that I can get at the "Something" value by key.

Answer 2

This can be done with a little recursion. I'll leave defining IsJson up to you as an academic exercise. :)

Dictionary<string, object> RecursiveDeserialize(string json)
{
     var result = JsonConvert.DeserializeObject<Dictionary<string, object>>(json);
     foreach (var pair in result.ToArray())
     {
         if(IsJson(pair.Value))
         {
             result[pair.Key] = RecursiveDeserialize(pair.Value);
         }
     }
     return result;
}