Parse JSON without declaring model class

Question

I have JSON like this:

{
"bookings": {
    "group_id": "abc",
    "name": "Study Rooms",
    "url": "My URL",
    "timeslots": [{
            "room_id": "bcd",
            "room_name": "101",
            "booking_label": "Meeting1",
            "booking_start": "2018-11-30T07:00:00-06:00",
            "booking_end": "2018-11-30T07:30:00-06:00",
            "booking_created": "2018-11-28T11:32:32-06:00"
        }, {
            "room_id": "cde",
            "room_name": "102",
            "booking_label": "Meeting2",
            "booking_start": "2018-11-30T07:30:00-06:00",
            "booking_end": "2018-11-30T08:00:00-06:00",
            "booking_created": "2018-11-28T11:32:32-06:00"
        }, //##AND many more like this##
    ]
}
}

If I try to parse it like this:

var reservations = new { bookings = new { group_id = "", name = "", url="", timeslots = new List<Timeslot>() } };
Newtonsoft.Json.JsonConvert.PopulateObject(jsonResult, reservations);

Only timeslots element gets populated

However, if I declare a model class with properties groop_id, name, url, and timeslots collection, and parse like this:

var reservations = new { bookings = new BookingsModel() };
Newtonsoft.Json.JsonConvert.PopulateObject(jsonResult, reservations);

It works fine.

Question is WHY, and is it possible to parse all elements of JSON without static declaration of the model.

Don't have time to go into the why but look at the `Dynamic` object type, https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/types/using-type-dynamic — Sean T, Dec 05 '18 at 16:24
@maccettura I've come accross use cases where I've had to use it, but generally I agree, c# is meant to have static type checking — Sean T, Dec 05 '18 at 16:26
`...and is it possible to parse all elements of JSON without static declaration of the model.` <-- Then why put this? You've clearly posted a 2 part question. I've answered the second part — Sean T, Dec 05 '18 at 16:30
@shlasasha - you JSON is not well formed: 1) There was an incorrect number of closing braces and brackets at the end. Assuming this to be an error in the question, I fixed it. 2) Numbers with leading zeros like this: `"room_id": 0001` are invalid according to the [JSON standard](https://json.org/). For why see [Why is JSON invalid if an integer begins with 0](https://stackoverflow.com/q/27361565). Json.NET interprets these as [Octal](https://stackoverflow.com/q/29048110) which doesn't help you here, you will need to fix the JSON. — dbc, Dec 05 '18 at 17:01
@dbc Thank you. I messed up writing this post my real json is a little different, so this is not the reason for my problem. — shlasasha, Dec 05 '18 at 17:17

dbc · Accepted Answer · 2019-05-11T20:20:46.113

3

The reason that you are not able to populate your anonymous object is that, in c#, anonymous types are immutable.

Instead, you may use JsonConvert.DeserializeAnonymousType() which will create a new instance of your anonymous type from your existing instance:

var reservations = Newtonsoft.Json.JsonConvert.DeserializeAnonymousType(jsonResult, 
        new { bookings = 
            new { group_id = default(string), name = default(string), url=default(string), 
                 timeslots = default(List<Timeslot>) } });

Sample fiddle here.

edited May 11 '19 at 20:20

answered Dec 05 '18 at 16:43

dbc

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Thank you! actually this works too: `var rr = new { bookings = new { group_id = "", name = "", url="", timeslots = new List() } };` `var a = Newtonsoft.Json.JsonConvert.DeserializeObject(jsonResult, rr.GetType());` – shlasasha Dec 05 '18 at 17:21

score 0 · Answer 2 · answered Dec 05 '18 at 16:38

0

your asking why
group_id, name, and url arent getting populated?

its because theres no actual value in it.

look at the parameter for JsonSerializerSettings

answered Dec 05 '18 at 16:38

Mookie

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9

Parse JSON without declaring model class

2 Answers2

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