C# JSON Object wont deserialize

Question

So I have been able to get JSON objects for a few things, however this object is quite a bit more complex.

I'm trying to get comments from Reddit. Here is the method I use:

    public async Task<List<string>> GetComments(string currentSubreddit, string topicID)
    {
        string commentUrl = "http://www.reddit.com/r/" + currentSubreddit  + "/comments/" + topicID + "/.json";
        List<Comments> commentList = new List<Comments>();
        string jsonText = await wc.GetJsonText(commentUrl);

        Comments.RootObject deserializeObject = Newtonsoft.Json.JsonConvert.DeserializeObject<Comments.RootObject>(jsonText);

        List<string> commentListTest = new List<string>();
        //List<string> commentListTest = deserializeObject.data.children[0].data.children;
        return commentListTest;

    }

This is the GetJsonText method:

    public async Task<string> GetJsonText(string url)
    {
        var request = WebRequest.Create(url);
        string text;
        request.ContentType = "application/json; charset=utf-8";
        var response = (HttpWebResponse)await request.GetResponseAsync();

        using (var sr = new StreamReader(response.GetResponseStream()))
        {
            text = sr.ReadToEnd();
        }

        return text;
    }

And here is a link to the Object: http://pastebin.com/WQ8XXGNA And a link to the jsonText: http://pastebin.com/7Kh6cA9a

The error returned says this:

An exception of type 'Newtonsoft.Json.JsonSerializationException' occurred in mscorlib.dll but was not handled in user code

Additional information: Cannot deserialize the current JSON array (e.g. [1,2,3]) into type 'JuicyReddit.Comments+RootObject' because the type requires a JSON object (e.g. {"name":"value"}) to deserialize correctly.

I'd appreciate if anybody could help me with figuring out whats wrong with this. Thanks

Answer 1

It's not ideal (and not completely an answer but more of a work around) but I created models that mock the reddit response json to make deserialization super easy. I use JsonProperty attributes on my model properties to pretty up the models a bit.

Here are the models

And since my models directly mock the json I can just use json.net's generic deserialize method.

Answer 2

There are a few problems with your code actually

 public async Task<List<string>> GetComments(string currentSubreddit, string topicID)

You don't need to return a list of string here, u need to return a full object

First rename RootObject in the model to an appropriate name such as "CommentsObject"

So set up your class like so and name it CommentsObject.cs:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace YOURNAMESPACE.Comments
{
    public class MediaEmbed
    {
    }

    public class SecureMediaEmbed
    {
    }

    public class Data4
    {
        public int count { get; set; }
        public string parent_id { get; set; }
        public List<string> children { get; set; }
        public string name { get; set; }
        public string id { get; set; }
        public string subreddit_id { get; set; }
        public object banned_by { get; set; }
        public string subreddit { get; set; }
        public object likes { get; set; }
        public object replies { get; set; }
        public bool? saved { get; set; }
        public int? gilded { get; set; }
        public string author { get; set; }
        public object approved_by { get; set; }
        public string body { get; set; }
        public object edited { get; set; }
        public object author_flair_css_class { get; set; }
        public int? downs { get; set; }
        public string body_html { get; set; }
        public string link_id { get; set; }
        public bool? score_hidden { get; set; }
        public double? created { get; set; }
        public object author_flair_text { get; set; }
        public double? created_utc { get; set; }
        public object distinguished { get; set; }
        public object num_reports { get; set; }
        public int? ups { get; set; }
    }

    public class Child2
    {
        public string kind { get; set; }
        public Data4 data { get; set; }
    }

    public class Data3
    {
        public string modhash { get; set; }
        public List<Child2> children { get; set; }
        public object after { get; set; }
        public object before { get; set; }
    }

    public class Replies
    {
        public string kind { get; set; }
        public Data3 data { get; set; }
    }

    public class Data2
    {
        public string domain { get; set; }
        public object banned_by { get; set; }
        public MediaEmbed media_embed { get; set; }
        public string subreddit { get; set; }
        public object selftext_html { get; set; }
        public string selftext { get; set; }
        public object likes { get; set; }
        public object secure_media { get; set; }
        public object link_flair_text { get; set; }
        public string id { get; set; }
        public SecureMediaEmbed secure_media_embed { get; set; }
        public bool clicked { get; set; }
        public bool stickied { get; set; }
        public string author { get; set; }
        public object media { get; set; }
        public int score { get; set; }
        public object approved_by { get; set; }
        public bool over_18 { get; set; }
        public bool hidden { get; set; }
        public string thumbnail { get; set; }
        public string subreddit_id { get; set; }
        public object edited { get; set; }
        public object link_flair_css_class { get; set; }
        public object author_flair_css_class { get; set; }
        public int downs { get; set; }
        public bool saved { get; set; }
        public bool is_self { get; set; }
        public string permalink { get; set; }
        public string name { get; set; }
        public double created { get; set; }
        public string url { get; set; }
        public object author_flair_text { get; set; }
        public string title { get; set; }
        public double created_utc { get; set; }
        public int ups { get; set; }
        public int num_comments { get; set; }
        public bool visited { get; set; }
        public object num_reports { get; set; }
        public object distinguished { get; set; }
        public Replies replies { get; set; }
        public int? gilded { get; set; }
        public string parent_id { get; set; }
        public string body { get; set; }
        public string body_html { get; set; }
        public string link_id { get; set; }
        public bool? score_hidden { get; set; }
        public int? count { get; set; }
        public List<string> children { get; set; }
    }

    public class Child
    {
        public string kind { get; set; }
        public Data2 data { get; set; }
    }

    public class Data
    {
        public string modhash { get; set; }
        public List<Child> children { get; set; }
        public object after { get; set; }
        public object before { get; set; }
    }

    public class CommentsObject
    {
        public string kind { get; set; }
        public Data data { get; set; }
    }
}

Make your namespace correct!

Then handle the request and deserialise into a list of commentobjects: (u can use the webclient instead of httpclient if you want, this is just an example)

    private HttpClient client;

    public async Task<List<CommentsObject>> GetComments()
    {
        client = new HttpClient();
        var response = await client.GetAsync("http://www.reddit.com/r/AskReddit/comments/1ut6xc.json");
        if (response.IsSuccessStatusCode)
        {
            string json = await response.Content.ReadAsStringAsync();
            List<CommentsObject> comments = await JsonConvert.DeserializeObjectAsync<List<CommentsObject>>(json);
            return comments;
        }
        else
        {
            throw new Exception("Errorhandling message");
        }
    }