Using system.text.json with Azure Functions

Question

I am trying to find good code examples of using System.Text.Json with Azure Functions

I understand it's still a fairly new package but it's performance benefits are compelling, what I can't find is a simple example to import it in an Azure Function and do a basic JSON serialise and deserialise call.

E.g for a httpclient postasync call using Functions v4

Answer 1

One of the workaround I did of basic JSON Serialize and deserialize call in Azure Functions v4 Http Request with both Get and Post Methods using async operator:

1. Created Azure Functions v4 of Stack .Net Core 6 in Visual Studio. Here is the .csproj code:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
    <AzureFunctionsVersion>v4</AzureFunctionsVersion>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.NET.Sdk.Functions" Version="4.0.1" />
    <!--<PackageReference Include="Polly" Version="7.2.3" />
    <PackageReference Include="Polly.Extensions.Http" Version="3.0.0" />-->
  </ItemGroup>
  <ItemGroup>
    <None Update="host.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </None>
    <None Update="local.settings.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
      <CopyToPublishDirectory>Never</CopyToPublishDirectory>
    </None>
  </ItemGroup>
</Project>

2. Added a new class called Entity to the same project. Its code:

using System;
using System.Collections.Generic;
using System.Text.Json.Serialization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace KrishAzFuncNet6Http
{
    internal class Entity
    {
        public enum ProductType
        {
            Book,
            Album,
            Cinema
        }

        public class Product
        {
            [JsonPropertyName("id")]
            public Guid Id { get; set; }

            [JsonPropertyName("type")]
            public ProductType Type { get; set; }

            [JsonPropertyName("is_ready")]
            public bool IsReady { get; set; }

            [JsonPropertyName("name")]
            public string Name { get; set; }

            [JsonPropertyName("revision")]
            public int Revision { get; set; }

            [JsonPropertyName("authors")]
            public IList<string> Authors { get; set; }

            [JsonPropertyName("registed_at")]
            public DateTime RegistedAt { get; set; }

            [JsonPropertyName("updated_at")]
            public DateTime UpdatedAt { get; set; }
            }
        }
    }

3. Modified the Http Trigger Function class accordingly to serialize in respective JSON Format as its code is in below:

using System;
using System.IO;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;
using System.Collections.Generic;
using static KrishAzFuncNet6Http.Entity;
using System.Text.Json;


namespace Company.Function
{
    public static class HttpTrigger1
    {
        [FunctionName("HttpTrigger1")]
        public static async Task<IActionResult> Run(
            [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post")] HttpRequest req,
            ILogger log)
        {
            log.LogInformation("C# HTTP trigger function processed a request.");

            var product = new Product
            {
                Id = Guid.NewGuid(),
                Type = ProductType.Cinema,
                IsReady = false,
                Name = "Hari",
                Revision = 1,
                Authors = new List<string> { "Krishna", "Rajoli" },
                RegistedAt = DateTime.UtcNow,
                UpdatedAt = DateTime.UtcNow
            };
            var json = System.Text.Json.JsonSerializer.Serialize(product);

            string responseMessage = json;
            return new OkObjectResult(responseMessage);

        }
    }
}

local.settings.json:

{
  "IsEncrypted": false,
  "Values": {
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
    "FUNCTIONS_WORKER_RUNTIME": "dotnet"
  }
}

GET Request:

POST Request call: