How to deserialize variable size JSON string with variable names

Question

Deserializing a small, fixed size, fixed structure, with fixed field names, JSON string is easy: Just define a class that contains all the fields (with correct types and names, all known at compile time).

Deserializing a variable-size of repeating nested pairs, is somewhat more challenging but can be done with the help of a List<> inside the class.

But what do I do when the name of the fields are unknown at compile time? e.g.:

{
   "container":{
      "GD01AB491103":{
         "field_id1":11,
         "field_id2":12,
         "field_id3":13,
         "field_id4":"fourteen"
      },
      "DC01AB491103":{
         "field_id1":21,
         "field_id2":22,
         "field_id3":23,
         "field_id4":"twenty four"
      },
      "GH01AB451101":{
         "field_id1":31,
         "field_id2":32,
         "field_id3":33,
         "field_id4":"thirty four"
      }
      .
      .
      .
   },
   "terminator"
}

How to deserialize such a string?

(preferably with .NET's JavaScriptSerializer but if it's too weak/incapable, I might need to resort to something else)

Edit: To clarify the nature of the challenge: In the example above, in order to define a class:

public class ??????
{
    public int field_id1  {get;set;}
    public int field_id2  {get;set;}
    public int field_id3  {get;set;}
    public string field_id4 {get;set;}
}

I need to query the JSON string first, then at runtime build classes (reflection?) with these variable-name class objects in it? Looks too cumbersome... Perhaps there is a saner way?

Or maybe the class/field names are irrelevant to .NET's JavaScriptSerializer and all matters is the type? (and correct structure of course)

Reinaldoreinaldos

Answer 1

You can do this probably more simply than you think.. your ?????? class can be anything..

public class GenericObject
{
    public int field_id1  {get;set;}
    public int field_id2  {get;set;}
    public int field_id3  {get;set;}
    public string field_id4 {get;set;}
}

and then deserialize the root of the object graph into an object that contains a Dictionary<string,GenericObject>...

public class SomeContainer
{
    public Dictionary<string,GenericObject> container {get;set;}
}

you can then loop over the values of the dictionary if you don't care about the names of the keys.

Nephro

Thanks. In my quest for ways to make this process simpler I found this great site which automated C# class building from a given JSON string: json2csharp.com – Reinaldoreinaldos

Actually, it works with both JSON.net and .NET's JavaScriptSerializer. – Reinaldoreinaldos

Yeah it should be pretty serializer independent the one concern I had was with the trailing "terminator" entry because it isn't valid JSON but as long as that is only a hint then you should be fine. FWIW if you have the option (and not too nuanced .net generics) I would recommend JSON.net over JavaScriptSerializer for performance reasons. – Nephro