C#•2y ago

❔ HTTP request object creation / ignoring fields when deserializing JSON

Hey there. I am writing a program using the Deck of Cards API which can be found here: https://deckofcardsapi.com/. The API returns a response which contains JSON.

class Deck 
{
  public Deck() { ... }
  public Card DrawCard() { ... }
}

class Deck 
{
  public Deck() { ... }
  public Card DrawCard() { ... }
}

I have a class named "Deck", I first wanted "Deck" to load and deserialize itself in the constructor using the API but I don't really know if that's possible or a good idea. I am wondering if there are better alternatives or best practices for this problem.

class Card
{
  public string Value;
  public string Suit;
  public string Image;
}

class Card
{
  public string Value;
  public string Suit;
  public string Image;
}

I also have a second problem. Whenever I want to request a card using the API, the response contains many properties I don't need. Is there a way of only deserializing certain properties? Above you can see a class called "Card" and I only need "Value", "Suit", and "Image" but the JSON in the response contains much more as you can see below. Response when drawing card(s).

{
    "success": true, 
    "deck_id": "kxozasf3edqu", 
    "cards": [
        {
            "code": "6H", 
            "image": "https://deckofcardsapi.com/static/img/6H.png", 
            "images": {
                          "svg": "https://deckofcardsapi.com/static/img/6H.svg", 
                          "png": "https://deckofcardsapi.com/static/img/6H.png"
                      }, 
            "value": "6", 
            "suit": "HEARTS"
        }, 
        {
            "code": "5S", 
            "image": "https://deckofcardsapi.com/static/img/5S.png", 
            "images": {
                          "svg": "https://deckofcardsapi.com/static/img/5S.svg", 
                          "png": "https://deckofcardsapi.com/static/img/5S.png"
                      }, 
            "value": "5", 
            "suit": "SPADES"
        }
    ], 
    "remaining": 50
}

{
    "success": true, 
    "deck_id": "kxozasf3edqu", 
    "cards": [
        {
            "code": "6H", 
            "image": "https://deckofcardsapi.com/static/img/6H.png", 
            "images": {
                          "svg": "https://deckofcardsapi.com/static/img/6H.svg", 
                          "png": "https://deckofcardsapi.com/static/img/6H.png"
                      }, 
            "value": "6", 
            "suit": "HEARTS"
        }, 
        {
            "code": "5S", 
            "image": "https://deckofcardsapi.com/static/img/5S.png", 
            "images": {
                          "svg": "https://deckofcardsapi.com/static/img/5S.svg", 
                          "png": "https://deckofcardsapi.com/static/img/5S.png"
                      }, 
            "value": "5", 
            "suit": "SPADES"
        }
    ], 
    "remaining": 50
}

Deck of Cards

Deck of Cards - an API for playing cards.

24 Replies

Angius•2y ago

Regarding the first question, constructors cannot be asynchronous, and HTTP calls should be

cap5lut•2y ago

regarding the second problem: it only cares about properties in ur poco: https://sharplab.io/#v2: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

Angius•2y ago

The usual way would be having some DeckService class that has an async Task<Deck> GetDeck() method For the latter, if the class you deserialize into has only selected properties... it will have only those

JochemOP•2y ago

Okay thank you both for the responses!

cap5lut•2y ago

generally i would say u need a bit more, the suit should be an enum, not a string, afaik stj can automatically translate strings to enums, but if not u might need a little custom converter for that enum

Angius•2y ago

STJ should be able to convert strings to enums, yeah

cap5lut•2y ago

never touched it myself for enums so i want sure ;p i rarely use json nowadays but binary (de)serialization using source generates

JochemOP•2y ago

Yes, I read about custom converters but didn't know it could do that automatically? does it work when the enum name is not case-sensitive equal to the json value?

MODiX•2y ago

angius#0000

REPL Result: Failure

enum Letters { A, B, C }
record Foo(Letters thing);
System.Text.Json.JsonSerializer.Deserialize<Foo>("""
{
  "thing": "A"
}
""")

enum Letters { A, B, C }
record Foo(Letters thing);
System.Text.Json.JsonSerializer.Deserialize<Foo>("""
{
  "thing": "A"
}
""")

Exception: JsonException

- The JSON value could not be converted to Submission#0+Foo. Path: $.thing | LineNumber: 1 | BytePositionInLine: 14.

- The JSON value could not be converted to Submission#0+Foo. Path: $.thing | LineNumber: 1 | BytePositionInLine: 14.

Compile: 605.900ms | Execution: 84.837ms | React with ❌ to remove this embed.

Angius•2y ago

Doesn't work by default, alas

MODiX•2y ago

angius#0000

REPL Result: Failure

using System.Text.Json;

enum Letters { A, B, C }
record Foo(Letters thing);

JsonSerializerOptions options = new JsonSerializerOptions{
    Converters ={
        new JsonStringEnumConverter()
    }
};

JsonSerializer.Deserialize<Foo>("""
{
  "thing": "A"
}
""")

using System.Text.Json;

enum Letters { A, B, C }
record Foo(Letters thing);

JsonSerializerOptions options = new JsonSerializerOptions{
    Converters ={
        new JsonStringEnumConverter()
    }
};

JsonSerializer.Deserialize<Foo>("""
{
  "thing": "A"
}
""")

Exception: CompilationErrorException

- The type or namespace name 'JsonStringEnumConverter' could not be found (are you missing a using directive or an assembly reference?)

- The type or namespace name 'JsonStringEnumConverter' could not be found (are you missing a using directive or an assembly reference?)

Compile: 681.999ms | Execution: 0.000ms | React with ❌ to remove this embed.

Angius•2y ago

Huh, thought it's an existing converter?

cap5lut•2y ago

i think in this case u would even want a custom serializer if i understand it correctly, cuz in ur enum u would use the singular

public enum Suits
{
  Heart,
  Club,
  Spade,
  blah
}

public enum Suits
{
  Heart,
  Club,
  Spade,
  blah
}

(cant remenber the other one in english :'D) but the api spits it out as plurar (hearts, clubs, spades, blahs)

MODiX•2y ago

cap5lut#0000

REPL Result: Failure

using System.Text.Json;
using System.Text.Json.Serialization;

enum Letters { A, B, C }
record Foo(Letters thing);

JsonSerializerOptions options = new JsonSerializerOptions{
    Converters ={
        new JsonStringEnumConverter()
    }
};

JsonSerializer.Deserialize<Foo>("""
{
  "thing": "A"
}
""")

using System.Text.Json;
using System.Text.Json.Serialization;

enum Letters { A, B, C }
record Foo(Letters thing);

JsonSerializerOptions options = new JsonSerializerOptions{
    Converters ={
        new JsonStringEnumConverter()
    }
};

JsonSerializer.Deserialize<Foo>("""
{
  "thing": "A"
}
""")

Exception: JsonException

- The JSON value could not be converted to Submission#0+Foo. Path: $.thing | LineNumber: 1 | BytePositionInLine: 14.

- The JSON value could not be converted to Submission#0+Foo. Path: $.thing | LineNumber: 1 | BytePositionInLine: 14.

Compile: 689.527ms | Execution: 103.512ms | React with ❌ to remove this embed.

cap5lut•2y ago

hmm ._. we dont pass the options xD

MODiX•2y ago

cap5lut#0000

REPL Result: Success

using System.Text.Json;
using System.Text.Json.Serialization;

enum Letters { A, B, C }
record Foo(Letters thing);

JsonSerializerOptions options = new JsonSerializerOptions{
    Converters ={
        new JsonStringEnumConverter()
    }
};

JsonSerializer.Deserialize<Foo>("""
{
  "thing": "A"
}
""", options)

using System.Text.Json;
using System.Text.Json.Serialization;

enum Letters { A, B, C }
record Foo(Letters thing);

JsonSerializerOptions options = new JsonSerializerOptions{
    Converters ={
        new JsonStringEnumConverter()
    }
};

JsonSerializer.Deserialize<Foo>("""
{
  "thing": "A"
}
""", options)

Result: Foo

{
  "thing": 0
}

{
  "thing": 0
}

Compile: 719.373ms | Execution: 95.137ms | React with ❌ to remove this embed.

Angius•2y ago

lmao Yeah, it'll work now

Pobiega•2y ago

it is, but iirc its in a different namespace

cap5lut•2y ago

yep using System.Text.Json.Serialization;

Pobiega•2y ago

as above 😄

MODiX•2y ago

angius#0000

REPL Result: Success

using System.Text.Json;
using System.Text.Json.Serialization;

enum Letters { A, B, C }
record Foo(Letters thing);

JsonSerializerOptions options = new JsonSerializerOptions{
    Converters ={
        new JsonStringEnumConverter()
    }
};

var res = JsonSerializer.Deserialize<Foo>("""
{
  "thing": "A"
}
""", options);

res is { thing: Letters.A }

using System.Text.Json;
using System.Text.Json.Serialization;

enum Letters { A, B, C }
record Foo(Letters thing);

JsonSerializerOptions options = new JsonSerializerOptions{
    Converters ={
        new JsonStringEnumConverter()
    }
};

var res = JsonSerializer.Deserialize<Foo>("""
{
  "thing": "A"
}
""", options);

res is { thing: Letters.A }

Result: bool

True

True

Compile: 735.518ms | Execution: 107.051ms | React with ❌ to remove this embed.

Angius•2y ago

Yeah, deserializes to an enum just fine

cap5lut•2y ago

that will probably still apply, or am i wrong here? oh wait wrong referenced message this one ⤴️

Accord•2y ago

Was this issue resolved? If so, run /close - otherwise I will mark this as stale and this post will be archived until there is new activity.

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❔ HTTP request object creation / ignoring fields when deserializing JSON