C#•7mo ago

CatAPI Json deserialization issue.

I'm having trouble getting my code to deserialize my json correctly. When I run my Program.cs I get

API Response: [{"id":"530","url":"https://cdn2.thecatapi.com/images/530.jpg","width":448,"height":538}]
Deserialized Cat URL: 
value=HereKitty.RandomCat
url=

API Response: [{"id":"530","url":"https://cdn2.thecatapi.com/images/530.jpg","width":448,"height":538}]
Deserialized Cat URL: 
value=HereKitty.RandomCat
url=

But I'm not able to access the fields in the json. My Program.cs

        var filePath = "/home/deca/auth/cat_api.json";
        using var doc = JsonDocument.Parse(File.ReadAllText(filePath));
        var apiKey = doc.RootElement.GetProperty("api_key").GetString();
        var kitty = new HereKitty(apiKey);
        
        var response = await kitty.GetRandomCatAsync();
        Console.WriteLine($"value={response}");
        Console.WriteLine($"url={response.Url}");

        var filePath = "/home/deca/auth/cat_api.json";
        using var doc = JsonDocument.Parse(File.ReadAllText(filePath));
        var apiKey = doc.RootElement.GetProperty("api_key").GetString();
        var kitty = new HereKitty(apiKey);
        
        var response = await kitty.GetRandomCatAsync();
        Console.WriteLine($"value={response}");
        Console.WriteLine($"url={response.Url}");

my Json class

public class RandomCat
{
    public string Id { get; set; }
    public string Url { get; set; }
    public int Width { get; set; }
    public int Height { get; set; } 
}

public class RandomCat
{
    public string Id { get; set; }
    public string Url { get; set; }
    public int Width { get; set; }
    public int Height { get; set; } 
}

the response

{"id":"530","url":"https://cdn2.thecatapi.com/images/530.jpg","width":448,"height":538}

{"id":"530","url":"https://cdn2.thecatapi.com/images/530.jpg","width":448,"height":538}

my function

    public async Task<RandomCat> GetRandomCatAsync()
    {
        var response = await _httpClient.GetAsync("images/search");
        response.EnsureSuccessStatusCode();
        var responseBody = await response.Content.ReadAsStringAsync();
        Console.WriteLine($"API Response: {responseBody}");
       using var jData = JsonDocument.Parse(responseBody);
        var catData = jData.RootElement[0]; // Access the first element of the JSON array

        RandomCat cat = JsonSerializer.Deserialize<RandomCat>(catData.GetRawText()); // Deserialize the first element
        Console.WriteLine($"Deserialized Cat URL: {cat?.Url}"); 
        return cat;
    }

    public async Task<RandomCat> GetRandomCatAsync()
    {
        var response = await _httpClient.GetAsync("images/search");
        response.EnsureSuccessStatusCode();
        var responseBody = await response.Content.ReadAsStringAsync();
        Console.WriteLine($"API Response: {responseBody}");
       using var jData = JsonDocument.Parse(responseBody);
        var catData = jData.RootElement[0]; // Access the first element of the JSON array

        RandomCat cat = JsonSerializer.Deserialize<RandomCat>(catData.GetRawText()); // Deserialize the first element
        Console.WriteLine($"Deserialized Cat URL: {cat?.Url}"); 
        return cat;
    }

Does anyone know what I'm doing wrong?

7 Replies

Angius•7mo ago

The [] means the response is an array, so could be that Also, why fiddle around with non-type-safe JsonDocument and what not instead of just... parsing the response to JSON?

dan in a can•7mo ago

yeah use GetFromJsonAsync https://learn.microsoft.com/en-us/dotnet/api/system.net.http.json.httpclientjsonextensions.getfromjsonasync?view=net-7.0

Decabytes•7mo ago

Ahh Thank you! GetFromJsonAsync works so much better! The other way I was doing it was

        var response = await kitty.GetRandomCatAsync();
        using var jData = JsonDocument.Parse(response);
        var jDoc = jData.RootElement;
        var catData = jDoc[0];
        var url = catData.GetProperty("url").GetString();

        var response = await kitty.GetRandomCatAsync();
        using var jData = JsonDocument.Parse(response);
        var jDoc = jData.RootElement;
        var catData = jDoc[0];
        var url = catData.GetProperty("url").GetString();

which was pain.

PixxelKick•7mo ago

yeah its returning an array of RandomCat, not just 1

PixxelKick•7mo ago

it just happens to only be 1 item long So you wanna do JsonSerializer.Deserialize<RandomCat[]>

dan in a can•7mo ago

glad it works!

Mayor McCheese•7mo ago

Even just one cat has 9 lives

Gaming

Programming

CatAPI Json deserialization issue.