Parsing JSON with LINQ into List of Objects

Question

I'm a little confused on the best way to parse the following JSON structure.

{
"featured": {
    "id": 15,
    "title": "media 1 -> 7",
    "description": "test1",
    "short_description": "test1",
    "rating_avg": 0.0,
    "image": "//d25xdrj7gd7wz1.cloudfront.net/covers/1603/1452024324.jpg"
},
"categories": [
    {
        "id": 1,
        "title": "category 0",
        "description": null,
        "position": 0,
        "media": [
            {
                "id": 1,
                "title": "media 0 -> 0",
                "description": "test1",
                "short_description": "test1",
                "rating_avg": 0.0,
                "image": "//d25xdrj7gd7wz1.cloudfront.net/covers/1603/1452024324.jpg",
                "category_media": {
                    "position": 0,
                    "category_id": 1,
                    "media_id": 1,
                    "id": 1
                }
            }, ...

Basically I have an array of categories which contains an array of medias (the featured is for something else)

I am looking to return List and the Category object contains a List

and I created some models:

public class Category
{
    public string Id { get; set; }
    public string Title { get; set; }
    public string Description { get; set; }

    public List<Media> MediaList { get; set; }
}

public class Media
{
    public string Id { get; set; }
    public string Title { get; set; }
    public string Description { get; set; }
    public string ShortDescription { get; set; }
    public string Image { get; set; }
}

..and I am supposed to use Newtonsoft?

I looked at the following example: Deserializing Partial JSON Fragments but I would think I don't need to convert from JToken -> Category ... etc. In other words, I would think it would be easy to just return my List.

I'm new to LINQ (I come from a python background) so I'm getting to know C#

Tolulope · Accepted Answer · 2018-06-21 08:31:11Z

Use This as your Model

using System;
    using System.Collections.Generic;

    using System.Globalization;
    using Newtonsoft.Json;
    using Newtonsoft.Json.Converters;

    public partial class JsonModel
    {
        [JsonProperty("featured")]
        public Featured Featured { get; set; }

        [JsonProperty("categories")]
        public List<Category> Categories { get; set; }
    }

    public partial class Category
    {
        [JsonProperty("id")]
        public long Id { get; set; }

        [JsonProperty("title")]
        public string Title { get; set; }

        [JsonProperty("description")]
        public object Description { get; set; }

        [JsonProperty("position")]
        public long Position { get; set; }

        [JsonProperty("media")]
        public List<Featured> Media { get; set; }
    }

    public partial class Featured
    {
        [JsonProperty("id")]
        public long Id { get; set; }

        [JsonProperty("title")]
        public string Title { get; set; }

        [JsonProperty("description")]
        public string Description { get; set; }

        [JsonProperty("short_description")]
        public string ShortDescription { get; set; }

        [JsonProperty("rating_avg")]
        public long RatingAvg { get; set; }

        [JsonProperty("image")]
        public string Image { get; set; }

        [JsonProperty("category_media", NullValueHandling = NullValueHandling.Ignore)]
        public CategoryMedia CategoryMedia { get; set; }
    }

    public partial class CategoryMedia
    {
        [JsonProperty("position")]
        public long Position { get; set; }

        [JsonProperty("category_id")]
        public long CategoryId { get; set; }

        [JsonProperty("media_id")]
        public long MediaId { get; set; }

        [JsonProperty("id")]
        public long Id { get; set; }
    }
}

Then do this in your Class:

var info = JsonConvert.DeserializeObject<JsonModel>(json);
var featured = info.Featured;
var categories = info.Categories;

Alex Riabov · Accepted Answer · 2018-06-21 08:34:27Z

1

You don't need LINQ in this case unless you want to change the data structure. To parse json file to list you have to create a class that matches a structure of your file, like:

class DataModel
{
      public Featured Featured { get; set; }
      public List<Category> Categories { get;set; }
}

Also, please pay attention that you need to use attribute [JsonProperty(PropertyName="fieldName")] if property name in json is different from property name in class. And finally, to parse the data use the following row:

var data = JsonConvert.DeserializeObject<DataModel>(jsonString);

edited Jun 21, 2018 at 8:34

answered Jun 21, 2018 at 8:07

Alex Riabov

9,2865 gold badges50 silver badges48 bronze badges

Comments

Majid Parvin · Accepted Answer · 2018-06-21 08:12:54Z

Act as follow: Update your models with:

public class Category
{
    public string Id { get; set; }
    public string Title { get; set; }
    public string Description { get; set; }
    public List<Media> Media { get; set; }
}

public class Media
{
    public string Id { get; set; }
    public string Title { get; set; }
    public string Description { get; set; }
    public string ShortDescription { get; set; }
    public string Image { get; set; }
}

public class Featured
{
    public string Id { get; set; }
    public string Title { get; set; }
    public string Description { get; set; }
    public string Short_Description { get; set; }
}

And then make a model same as your JSON structure:

public class YOUR_MODEL
{
      public Featured Featured { get; set; }
      public List<Category> Categories { get;set; }
}

And then Descrilize your JSON to your object:

YOUR_MODELresults = JsonConvert.DeserializeObject<YOUR_MODEL>(YOUR_JSON);

AFract · Accepted Answer · 2018-06-21 08:22:37Z

To get your model you can use tool like : https://jsonutils.com/ or http://json2csharp.com/

In case of need you can also validate json syntax with : https://jsonlint.com/ to get detailed errors.

With a slightly modified version of your example, I get :

public class CategoryMedia
{
    public int position { get; set; }
    public int category_id { get; set; }
    public int media_id { get; set; }
    public int id { get; set; }
}

public class Medium
{
    public int id { get; set; }
    public string title { get; set; }
    public string description { get; set; }
    public string short_description { get; set; }
    public double rating_avg { get; set; }
    public string image { get; set; }
    public CategoryMedia category_media { get; set; }
}

public class Category
{
    public int id { get; set; }
    public string title { get; set; }
    public object description { get; set; }
    public int position { get; set; }
    public IList<Medium> media { get; set; }
}

public class Featured
{
    public int id { get; set; }
    public string title { get; set; }
    public string description { get; set; }
    public string short_description { get; set; }
    public double rating_avg { get; set; }
    public string image { get; set; }
    public IList<Category> categories { get; set; }
}

public class Example
{
    public Featured featured { get; set; }
}

It spares a lot of time for creating models and it allows you to verify that you don't have typos in field names.

With this, you just have to deserialize your JSON sample to "Example" class, using the library of your choice. Newtonsoft Json is a very efficient classical !

JohnChris · Accepted Answer · 2018-06-21 08:29:00Z

Newtonsoft is the standard for doing work like this. So lets look at the best way to do this. First lets start with your json format and fix it so you can use the online tools available to create a good model structure:

[
  {
    "featured": {
      "id": 15,
      "title": "media 1 -> 7",
      "description": "test1",
      "short_description": "test1",
      "rating_avg": 0.0,
      "image": "//d25xdrj7gd7wz1.cloudfront.net/covers/1603/1452024324.jpg"
    },
      "categories": [
        {
          "id": 1,
          "title": "category 0",
          "description": null,
          "position": 0,
          "media": [
            {
              "id": 1,
              "title": "media 0 -> 0",
              "description": "test1",
              "short_description": "test1",
              "rating_avg": 0.0,
              "image": "//d25xdrj7gd7wz1.cloudfront.net/covers/1603/1452024324.jpg",
              "category_media": {
                "position": 0,
                "category_id": 1,
                "media_id": 1,
                "id": 1
              }
            }
          ]
        }
      ]  
  }
]

Now if you plug that into http://json2csharp.com/, it will output a good model structure:

public class Featured
{
    public int id { get; set; }
    public string title { get; set; }
    public string description { get; set; }
    public string short_description { get; set; }
    public double rating_avg { get; set; }
    public string image { get; set; }
}

public class CategoryMedia
{
    public int position { get; set; }
    public int category_id { get; set; }
    public int media_id { get; set; }
    public int id { get; set; }
}

public class Medium
{
    public int id { get; set; }
    public string title { get; set; }
    public string description { get; set; }
    public string short_description { get; set; }
    public double rating_avg { get; set; }
    public string image { get; set; }
    public CategoryMedia category_media { get; set; }
}

public class Category
{
    public int id { get; set; }
    public string title { get; set; }
    public object description { get; set; }
    public int position { get; set; }
    public List<Medium> media { get; set; }
}

public class RootObject
{
    public Featured featured { get; set; }
    public List<Category> categories { get; set; }
}

Feel free to rename RootObject So now lets look are how you can deserialize your json into your model objects using Newtonsoft:

Firstly you need to get your json file into a string format, so lets say its a file on your computer or in your project, there is many ways to retrieve it, either using Assembly, or Directory methods. Once you have access to your json file, read out the contents and then using Newtonsoft method for deserialising:

var myString = File.ReadAllText(path)
var myObject = JsonConvert.DeserializeObject<RootObject>(myString);

And thats it:P

This naming convention contradicts C# standards and may confuse a person who is new to the language that it is normal

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