How do I return JSON from an Azure Function

Question

I am playing with Azure Functions. However, I feel like I'm stumped on something pretty simple. I'm trying to figure out how to return some basic JSON. I'm not sure how to create some JSON and get it back to my request.

Once upon a time, I would create an object, populate its properties, and serialize it. So, I started down this path:

#r "Newtonsoft.Json"

using System.Net;

public static async Task<HttpResponseMessage> Run(HttpRequestMessage req, TraceWriter log)
{
    log.Info($"Running Function");    
    try {      
      log.Info($"Function ran");

      var myJSON = GetJson();

      // I want myJSON to look like:
      // {
      //   firstName:'John',
      //   lastName: 'Doe',
      //   orders: [
      //     { id:1, description:'...' },
      //     ...
      //   ]
      // }
      return ?;
    } catch (Exception ex) {
        // TODO: Return/log exception
        return null;
    }
}

public static ? GetJson() 
{
  var person = new Person();
  person.FirstName = "John";
  person.LastName = "Doe";

  person.Orders = new List<Order>();
  person.Orders.Add(new Order() { Id=1, Description="..." });

  ?
}

public class Person 
{
  public string FirstName { get; set; }
  public string LastName { get; set; }
  public List<Order> Orders { get; set; }
}

public class Order
{
  public int Id { get; set; }
  public string Description { get; set; }
}

However, I'm totally stuck on the serialization and return process now.I guess I'm used to returning JSON in ASP.NET MVC where everything is an Action

Answer 1

Here's a full example of an Azure function returning a properly formatted JSON object instead of XML:

#r "Newtonsoft.Json"
using System.Net;
using Newtonsoft.Json;
using System.Text;

public static async Task<HttpResponseMessage> Run(HttpRequestMessage req, TraceWriter log)
{
    var myObj = new {name = "thomas", location = "Denver"};
    var jsonToReturn = JsonConvert.SerializeObject(myObj);

    return new HttpResponseMessage(HttpStatusCode.OK) {
        Content = new StringContent(jsonToReturn, Encoding.UTF8, "application/json")
    };
}

Navigate to the endpoint in a browser and you will see:

{
  "name": "thomas",
  "location": "Denver"
}