ASP.NET Core Get Json Array using IConfiguration

Question

In appsettings.json

{
      \"MyArray\": [
          \"str1\",
          \"str2\",
          \"str3\"
      ]
}

---

In Startup.cs

Answer 1

For the case of returning an array of complex JSON objects from configuration, I've adapted @djangojazz's answer to use anonymous types and dynamic rather than tuples.

Given a settings section of:

"TestUsers": [
{
  "UserName": "TestUser",
  "Email": "Test@place.com",
  "Password": "P@ssw0rd!"
},
{
  "UserName": "TestUser2",
  "Email": "Test2@place.com",
  "Password": "P@ssw0rd!"
}],

You can return the object array this way:

public dynamic GetTestUsers()
{
    var testUsers = Configuration.GetSection("TestUsers")
                    .GetChildren()
                    .ToList()
                    .Select(x => new {
                        UserName = x.GetValue<string>("UserName"),
                        Email = x.GetValue<string>("Email"),
                        Password = x.GetValue<string>("Password")
                    });

    return new { Data = testUsers };
}

Answer 2

This worked for me to return an array of strings from my config:

var allowedMethods = Configuration.GetSection("AppSettings:CORS-Settings:Allow-Methods")
    .Get<string[]>();

My configuration section looks like this:

"AppSettings": {
    "CORS-Settings": {
        "Allow-Origins": [ "http://localhost:8000" ],
        "Allow-Methods": [ "OPTIONS","GET","HEAD","POST","PUT","DELETE" ]
    }
}

Answer 3

appsettings.json:

"MySetting": {
  "MyValues": [
    "C#",
    "ASP.NET",
    "SQL"
  ]
},

MySetting class:

namespace AspNetCore.API.Models
{
    public class MySetting : IMySetting
    {
        public string[] MyValues { get; set; }
    }

    public interface IMySetting
    {
        string[] MyValues { get; set; }
    }
}

Startup.cs

public void ConfigureServices(IServiceCollection services)
{
    ...
    services.Configure<MySetting>(Configuration.GetSection(nameof(MySetting)));
    services.AddSingleton<IMySetting>(sp => sp.GetRequiredService<IOptions<MySetting>>().Value);
    ...
}

Controller.cs

public class DynamicController : ControllerBase
{
    private readonly IMySetting _mySetting;

    public DynamicController(IMySetting mySetting)
    {
        this._mySetting = mySetting;
    }
}

Access values:

var myValues = this._mySetting.MyValues;

Answer 4

If you want to pick value of first item then you should do like this-

var item0 = _config.GetSection("MyArray:0");

If you want to pick value of entire array then you should do like this-

IConfigurationSection myArraySection = _config.GetSection("MyArray");
var itemArray = myArraySection.AsEnumerable();

Ideally, you should consider using options pattern suggested by official documentation. This will give you more benefits.

Answer 5

Kind of an old question, but I can give an answer updated for .NET Core 2.1 with C# 7 standards. Say I have a listing only in appsettings.Development.json such as:

"TestUsers": [
  {
    "UserName": "TestUser",
    "Email": "Test@place.com",
    "Password": "P@ssw0rd!"
  },
  {
    "UserName": "TestUser2",
    "Email": "Test2@place.com",
    "Password": "P@ssw0rd!"
  }
]

I can extract them anywhere that the Microsoft.Extensions.Configuration.IConfiguration is implemented and wired up like so:

var testUsers = Configuration.GetSection("TestUsers")
   .GetChildren()
   .ToList()
    //Named tuple returns, new in C# 7
   .Select(x => 
         (
          x.GetValue<string>("UserName"), 
          x.GetValue<string>("Email"), 
          x.GetValue<string>("Password")
          )
    )
    .ToList<(string UserName, string Email, string Password)>();

Now I have a list of a well typed object that is well typed. If I go testUsers.First(), Visual Studio should now show options for the 'UserName', 'Email', and 'Password'.

Answer 6

Short form:

var myArray= configuration.GetSection("MyArray")
                        .AsEnumerable()
                        .Where(p => p.Value != null)
                        .Select(p => p.Value)
                        .ToArray();

It returns an array of string:

{"str1","str2","str3"}