In C# how can I deserialize this json when one field might be a string or an array of strings?

Question

I have an asp.net-mvc website and i am reading in Json string from a Database. Here is the following json in a DB. It could look like this:

{"description": "Test", "contacts": ["joe@gmail.com", "bill@yahoo.com"], "enabled": true}

or this:

{"description": "Test", "contacts": "joe@gmail.com, bill@yahoo.com", "enabled": true}

so as you can see, the contacts field is either:

1. a string (with items separated by commas)
2. an array of strings.

I want to convert to this class:

public class MyJob
{
    public string description;
    public string[] contacts;
    public string enabled;
}

when i try to assign just to a string (changing the above to this: public string contacts; ) using the JavascriptSerializer():

var serializer = new JavaScriptSerializer();
string contacts = serializer.Deserialize<MyJob>(theAboveJsonString).contacts;

I get this error in the cases where its an array: Type 'System.String' is not supported for deserialization of an array.

what is the best way to go about deserializing this to handle the case of:

1. a string
2. an array of strings.

for the contact field. I am happy to put any conditional logic needed . .

I tried this:

  var contacts = serializer.Deserialize<MyJob>(theAboveJsonString).contacts;
        if (contacts is string)
        {
            jobInfo.contacts = contacts;
        }
        else
        {
            jobInfo.contacts = String.Join("; ", contacts );
        }

but that didn't seem to fix as i am still getting the error above when its an array

Answer 1

try

  var contacts = (new JavaScriptSerializer().DeserializeObject(theAboveJsonString) as Dictionary<string, object>)["contacts"];

  if (contacts is object[])
  {
      jobInfo.contacts = String.Join("; ", contacts as object[]);
  }
  else
  {
      jobInfo.contacts = contacts.ToString(); 
  }

For reference see MSDN and here.

Answer 2

You may be interested in some details here: JSON.net - field is either string or List<string>

If you're willing to use Json.NET, have this function:

public string[] getAsArray(JToken token)
{
    if (token.HasValues)
    {
        return token.Select(m => string(m)).ToArray();
    }
    else
    {
        return ((string)token).Split(",").Select(s => s.Trim()).ToArray();
    }
}

Then usage:

var json = "...";
JObject o = JObject.Parse(json);
string[] contacts = getAsArray(o["contacts"]);

For either JSON the result should be the same.

Answer 3

Try to deserialize contacts into a string array instead of a plain string:

string[] contacts = serializer.Deserialize<MyJob>(theAboveJsonString).contacts;

if the JSON variable is holding a plain string, use:

string[] contacts = serializer.Deserialize<MyJob>(theAboveJsonString).contacts.Split(',');