c# - Get a list of JSON property names from a class to use in a query string

Question

If I have a C# model class that is used by JSON.net to bind data from a serialized JSON string, is there a way that I can create a query string from that class in order to make the initial request?

Model class example:

public class model
{
   [JsonProperty(PropertyName = "id")]
   public long ID { get; set; }
   [JsonProperty(PropertyName = "some_string")]
   public string SomeString {get; set;} 
}

Querystring example:

baseUrl + uri + "&fields=id,some_string" + token

So the essence of what I am trying to do is gather both "id" and "some_string" from the model object so i can dynamically create a the "&fields" arguments. Thanks!

Answer 1

@Leigh Shepperson has the right idea; however, you can do it with less code using LINQ. I would create a helper method like this:

using System.Linq;
using System.Reflection;
using Newtonsoft.Json;
...

public static string GetFields(Type modelType)
{
    return string.Join(",",
        modelType.GetProperties()
                 .Select(p => p.GetCustomAttribute<JsonPropertyAttribute>())
                 .Select(jp => jp.PropertyName));
}

You can use it like this:

var fields = "&fields=" + GetFields(typeof(model));

EDIT

If you're running under the 3.5 version of the .Net Framework such that you don't have the generic GetCustomAttribute<T> method available to you, you can do the same thing with the non-generic GetCustomAttributes() method instead, using it with SelectMany and Cast<T>:

    return string.Join(",",
        modelType.GetProperties()
                 .SelectMany(p => p.GetCustomAttributes(typeof(JsonPropertyAttribute))
                                   .Cast<JsonPropertyAttribute>())
                 .Select(jp => jp.PropertyName)
                 .ToArray());