How to Parse Json to obtains values

Question

This is the Json Format from the Imgur API using gallery search (heavily simplified, what matters is still there)

{
   "data":[
  {
     "id":"q33FYFh",
     "is_album":true,
     "images":[
        {
           "id":"ObcYQRc",
           "link":"https:\/\/i.imgur.com\/ObcYQRc.jpg",
           "is_album":false
        },
        {
           "id":"ifB0uac",
           "link":"https:\/\/i.imgur.com\/ifB0uac.jpg",
           "is_album":false
        }
     ]
  },
  {
     "id":"jYInL3c",
     "is_album":true,
     "images":[
        {
           "id":"bq2L5C4",
           "link":"https:\/\/i.imgur.com\/bq2L5C4.jpg",
           "is_album":false
        },
        {
           "id":"Z0OPngk",
           "link":"https:\/\/i.imgur.com\/Z0OPngk.jpg",
           "is_album":false
        }
     ]
  },
  {
     "id":"8xxM5TO",
     "link":"https:\/\/i.imgur.com\/8xxM5TO.jpg",
     "is_album":false
  }
   ],
   "success":true,
   "status":200
}

I need a way to get all image ID, not album ID, you can tell if an item is an album or a image by looking at the "is_album" tag

So first I tried to at least access the "id" subfield in the "images" field :

using Newtonsoft.Json;
string response = "Change this with the json file above"
dynamic dynJson = JsonConvert.DeserializeObject(response);
foreach (var data in dynJson)
{
            string id = data["images"]["id"].ToString();
            Debug.WriteLine(id);
}

This gave me this error : (By the way, I need to use Debug.WriteLine because Console doesn't work in PCL code in Xamarin.Forms)

System.InvalidOperationException: Cannot access child value on Newtonsoft.Json.Linq.JProperty.

But even if it worked, it would not get the id's for the images that are not part of an album.

using pseudo code this is what I would want (I think) :

for each (item in myjson)
{
  if (item.is_album == "false")
  {
      Console.write(item.id);
  }
  else
  {
       for each (image in element)
       {
           Console.write(image.id);
       }
  }
}

Answer 1

You are accessing the dynamic object incorrectly. Here is the code you need:

public static List<string> GetImageIds(string jsonData)
{
    List<string> imageIds = new List<string> ();

    dynamic temp = JsonConvert.DeserializeObject (jsonData);
    dynamic dynJson = temp.data;
    foreach (dynamic data in dynJson)
    {
        int j = 0;
        if (data.is_album == false)
        {
            imageIds.Add (data.id.ToString ());
        }
        else
        {
            dynamic images = data.images;
            foreach (var image in images)
            {
                imageIds.Add (image.id.ToString ());
            }
        }
    }

    return imageIds;
}

Note: This is a simple example of how to traverse dynamic object. You will need to add validations and business logic to it as needed per your need.

Hope this helps!

Answer 2

You are not accessing your data correctly based on your JSON data.

data is your top level array, so your foreach would look like this:

foreach (var data in dynJson["data"])

Inside your foreach you would access your images like this:

string id = data["images"][0]["id"].ToString();

Where 0 is the index of the images array.

So combining this with another loop to get all the images for that data:

foreach (var data in dynJson["data"])
{
    if (data["is_album"] == false)
    {
        // continue or do something
        continue;
    }
    foreach(var image in data["images"])
    {
        string id = image["id"].ToString();
        Debug.WriteLine(id);
    }
}