How to get multiple values of same variable in the function class from local.settings.json file?

Question

local.settings.json:

{
    "IsEncrypted": false,
    "Values": {
        "AzureWebJobsStorage": "UseDevelopmentStorage=true",
      "FUNCTIONS_WORKER_RUNTIME": "dotnet",
      "toAddress": [
        {
          "mail1": "******@gmail.com",
          "mail2": "******@hotmail.com",
          "mail3": "******@honda.com"
        }
      ]
    }
}

Function Class:

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.Configuration;
using Microsoft.Extensions.Configuration;

namespace ArrayVarPoC
{
    public class Function1
    {

        private readonly IConfiguration _config;
        public Function1(IConfiguration config)
        {

            _config = config;

        }
        [FunctionName("Function1")]
        public async Task<IActionResult> Run(
            [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)] HttpRequest req,
            ILogger log)
        {
            log.LogInformation("C# HTTP trigger function processed a request.");

            string[] toAddress = _config.GetValue<string[]>("toAddress");
            log.LogInformation($"[{toAddress.ToString}]");
            

            string responseMessage = "Hello Fish, This HTTP triggered function executed successfully.";

            return new OkObjectResult(responseMessage);
        }
    }
}

I'm able to get the single value of the variable defined in local.settings.json but not the array variable values.

I tried to get the array variable values defined the local.settings.json file to the function class but not sure how to write the code for it.

Could anyone help me how to get this?

Answer 1

billa Thanks for posting your question in Microsoft Q&A. As per doc: Local settings file, Values must be strings and not JSON objects or arrays.

However, you can define the values like below in the local.settings.json file (also application setting in azure; use__ for Linux instead of :) and use dependency injection to bind the values.

Local.settings.json

{
  "IsEncrypted": false,
  "Values": {
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
    "FUNCTIONS_WORKER_RUNTIME": "dotnet",
    "ToAddress:0:Mail1": "******@gmail.com",
    "ToAddress:0:Mail2": "******@hotmail.com",
    "ToAddress:0:Mail3": "******@honda.com"
  }
}

Startup.cs (Check Use dependency injection in .NET Azure Functions for detailed info about the dependency injection)

[assembly: FunctionsStartup(typeof(HttpTriggerParse.Startup))]
namespace HttpTriggerParse
{
    public class Startup : FunctionsStartup
    {
        public override void Configure(IFunctionsHostBuilder builder)
        {

            builder.Services.AddOptions<List<MailAddress>>()
                .Configure<IConfiguration>((settings, configuration) =>
                {
                    configuration.GetSection("ToAddress").Bind(settings);
                });
        }
    }
}

Function1.cs

public class Function1
    {
        private List<MailAddress> ToAddress;
        public Function1(IOptions<List<MailAddress>> mailAddresses)
        {
            ToAddress = mailAddresses.Value;
        }

        [FunctionName("Function1")]
        public async Task<IActionResult> Run(
            [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
            ILogger log)
        {
            log.LogInformation("C# HTTP trigger function processed a request.");

            string name = req.Query["name"];

            string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
            dynamic data = JsonConvert.DeserializeObject(requestBody);
            name = name ?? data?.name;

            string responseMessage = string.IsNullOrEmpty(name)
                ? "This HTTP triggered function executed successfully. Pass a name in the query string or in the request body for a personalized response."
                : $"Hello, {name}. This HTTP triggered function executed successfully.";

            return new OkObjectResult(responseMessage);
        }
    }

Output:

Also, check out similar discussion in SO thread and that might assist you with some questions. I hope this helps and let me know if you have any questions.

---

If you found the answer to your question helpful, please take a moment to mark it as "Yes" for others to benefit from your experience. Or simply add a comment tagging me and would be happy to answer your questions

Answer 2

Hi @krishna572 , Welcome to Microsoft Q&A.

You just need to use System.Text.Json to parse the json file.

You can parse it through the json file, and I will directly use json string to demonstrate:

using System;
using System.Collections.Generic;
using System.Text.Json;
namespace _7_21_x
{
    internal class Program
    {
        static void Main(string[] args)
        {
            string json = @"
        {
            ""IsEncrypted"": false,
            ""Values"": {
                ""AzureWebJobsStorage"": ""UseDevelopmentStorage=true"",
                ""FUNCTIONS_WORKER_RUNTIME"": ""dotnet"",
                ""toAddress"": [
                    {
                        ""mail1"": ""******@gmail.com"",
                        ""mail2"": ""******@hotmail.com"",
                        ""mail3"": ""******@honda.com""
                    }
                ]
            }
        }";

            // Deserialize the JSON to the RootObject
            var data = JsonSerializer.Deserialize<RootObject>(json);
            // Get all addresses
            var allAddresses = data.Values.toAddress;
            foreach (var address in allAddresses)
            {
                // Output mail attributes and their values
                foreach (var property in address.EnumerateObject())
                {
                    if (property.Value.ValueKind == JsonValueKind.String && property.Name.StartsWith("mail"))
                    {
                        Console.WriteLine($"{property.Name}: {property.Value.GetString()}");
                    }
                }
                Console.WriteLine();
            }
            Console.ReadLine();
        }
    }
    public class RootObject
    {
        public bool IsEncrypted
        {
            get;
            set;
        }
        public ValuesObject Values
        {
            get;
            set;
        }
    }
    public class ValuesObject
    {
        public string AzureWebJobsStorage
        {
            get;
            set;
        }
        public string FUNCTIONS_WORKER_RUNTIME
        {
            get;
            set;
        }
        public List<JsonElement> toAddress
        {
            get;
            set;
        }
    }
}

Best Regards,

Jiale

---

If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment". 

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.