Mapping JSON with date in object name to C# object

Question

I have JSON like this

    {
    "rates": {
        "2018-05-04": {
            "USD": 0.2813388807,
            "GBP": 0.2074019228
        },
        "2018-08-27": {
            "USD": 0.2723718099,
            "GBP": 0.2115780848
        }
        ...etc etc
    },
    "start_at": "2018-01-01",
    "base": "PLN",
    "end_at": "2018-09-01"
    }

I want to map it to C# object. I tried to use json@csharp, but it gives me something like this

public class __invalid_type__20180504
{
    public double USD { get; set; }
    public double GBP { get; set; }
}

public class __invalid_type__20180827
{
    public double USD { get; set; }
    public double GBP { get; set; }
}

public class Rates
{
    public __invalid_type__20180504 __invalid_name__2018-05-04 { get; set; }
    public __invalid_type__20180827 __invalid_name__2018-08-27 { get; set; }
}

public class RootObject
{
    public Rates rates { get; set; }
    public string start_at { get; set; }
    public string @base { get; set; }
    public string end_at { get; set; }
}

I do not want to have class names like "__invalid_type__xxxxxxxx", and I am looking for a way to map it to one class so that I have list of one class type. I am using DataContractJsonSerializer and System.Net.Http.HttpClient

the json is not valid - you need a property name for the date(s) — jazb, Nov 25 '19 at 07:12
because it does not know what "2018-05-04" and "2018-08-27" are, just adjust your class rate yo list of the subclass (which contains USD and GBP values) — styx, Nov 25 '19 at 07:12
@Jazb I've got json from here [link](https://api.exchangeratesapi.io/history?start_at=2018-01-01&end_at=2018-09-01&base=PLN&symbols=USD,GBP) — stefam mierz, Nov 25 '19 at 07:24
Does this answer your question? [How can I deserialize JSON to a simple Dictionary in ASP.NET?](https://stackoverflow.com/questions/1207731/how-can-i-deserialize-json-to-a-simple-dictionarystring-string-in-asp-net) — xdtTransform, Nov 25 '19 at 07:58
@Jazb, the Json is totaly valid under the [spec](http://www.json.org). Dictionary have unique key, and Array representation won't ensure uniqueness, Dict Key are mapped to Property Name and and Dict Value to Property Value. Every time you see something that look like an array but it's missing the `[]` or have "_property name as value_", it might be a `Dictionary`. like `{ "key1": "value1", "key2": "value2"}` — xdtTransform, Nov 25 '19 at 08:05

Eldar · Accepted Answer · 2019-11-25T08:07:20.077

2

You don't actually need to use a tool for generating classes for the json mentioned above. You can have a root object like this.

public class RootObject
{
    public Dictionary<string,Rate> rates { get; set; }
    public string start_at { get; set; }
    public string @base { get; set; }
    public string end_at { get; set; }
}

And since your property names are same for the rates you can use this for defining rate object.

public class Rate
{
    public double USD { get; set; }
    public double GBP { get; set; }
}

Since @stefammierz mentioned in the comment that he is using DataContractJsonSerializer, a trick is needed in order to make it work to deserialize to dictionary like below :

var settings = new DataContractJsonSerializerSettings {UseSimpleDictionaryFormat = true};
var serializer = new DataContractJsonSerializer(typeof(RootObject),settings);

edited Nov 25 '19 at 08:07

answered Nov 25 '19 at 07:16

Eldar

9,781
2
10
35

The root object is mapping, but rates disctionary is empty – stefam mierz Nov 25 '19 at 07:45
@stefammierz works perfectly but it is not the answer? – Eldar Nov 25 '19 at 08:28
I checked it as the answer – stefam mierz Nov 25 '19 at 08:31
One more question : is there a way for the list of currencies in the "Rate" class to be variable? e.g. once only gpb, other times usd, eur etc. – stefam mierz Nov 25 '19 at 08:35
You can make your Rate class contains all currencies. And define them as nullable. So only the defined ones in the json gets mapped. – Eldar Nov 25 '19 at 08:37

score 0 · Answer 2 · answered Nov 25 '19 at 07:31

When a JSON field name is dynamic, I.E the dates

you can use JsonExtensionData and yor data will have resulted as key:value pairs

So your classes look like these

        public class RootObject
        {
            public Rates rates { get; set; }
            public string start_at { get; set; }
            public string @base { get; set; }
            public string end_at { get; set; }
        }

        public class Rates
        {
            [JsonExtensionData]
            public Dictionary<string, JToken> Fields { get; set; }
        }

Example Output

Key: 2018-05-04

Value - { "USD": 0.2813388807, "GBP": 0.2074019228 }

Sushant Yelpale · Answer 3 · 2019-11-25T07:43:04.200

You can Just paste your Json here and create the class and Use NewtonsoftJson to parse,

public class RootObject
{
    [JsonProperty("rates")]
    public Dictionary<string, Dictionary<string, double>> Rates { get; set; }

    [JsonProperty("start_at")]
    public DateTimeOffset StartAt { get; set; }

    [JsonProperty("base")]
    public string Base { get; set; }

    [JsonProperty("end_at")]
    public DateTimeOffset EndAt { get; set; }
}

This is the best and quickest way I have seen so far.

Mapping JSON with date in object name to C# object

3 Answers3