CODEWITHSUNDEEP
c#jsonjson.net
Matt
Matt

Reputation: 1704

Deserializing generically typed classes with Newtonsoft

I have classes that look like this, based on the json being returned by Slack's api:

public class Response<T>
{
    public bool ok { get; set; }
    public string error { get; set; }
}

public class PostMessage : Response<PostMessage>
{
    public string ts { get; set; }
    public string channel { get; set; }
    public Message message { get; set; }
}

public class ChannelsHistory : Response<ChannelsHistory>
{
    public string latest { get; set; }
    public List<Message> messages { get; set; }
    public bool has_more { get; set; }
}

And I want to write a single method that can bottleneck the call to JsonConvert.DeserializeObject<T>. I don't know too much about the details of the implementation behind that method, but I thought that this would work:

internal static Response<T> GetSlackResponse<T>(List<KeyValuePair<string, string>> parameters = null)
    {
        Uri slackUri = BuidSlackUri(typeof(T), parameters);
        String jsonResponse = GetJson(slackUri);
        Response<T> response = JsonConvert.DeserializeObject<Response<T>>(jsonResponse);

        if (!response.ok)
        {
            Aesthetic.Catch("The Slack API failed to respond successfully. " + response.error);
        }

        return response;
    }

Nothing is failing, but not all of the properties I need are being deserialized. For example, a call to GetSlackResponse() will return a Response that has ok set to true, but I won't have access to the Message property of the PostMessage class. I've tried casting (both explicitly and with as), to no avail.

I'm sure I'm missing something simple here, can someone point it out?

Upvotes: 0

Views: 144

Answers (1)

Matt
Matt

Reputation: 1704

Having my various Response class extend a generically typed class was a red herring; it introduced nothing but making the problem more confusing. I only needed the method to be generic, not the type itself.

Changing the relevant line in GetSlackResponse<T>() method from 

Response<T> response = JsonConvert.DeserializeObject<Response<T>>(jsonResponse);

to 

 T response = JsonConvert.DeserializeObject<T>(jsonResponse);

fixed everything. Now my various response types only need to extend my base Response class, and will be properly deserialized by JSON.NET. There is no need for the response to be a generically typed object.

Upvotes: 1

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