Get Value from appsetting.json in class

Question

I have some appsetting.json below

{
  "MyConfig": {
    "FolderAnnouncement": "Duyuru\\",
    "BaseMediaUrl": "D:\\YoungTalent\\YTPanel\\YTPanel\\wwwroot\\images\\"
  },
  "ConnectionStrings": {
    "MySqlCon": "Server=localhost;Database=kariyer_portal;Uid=root;Pwd=1234;",
    "MsSqlCon": "Server=localhost\\SQLEXPRESS;Database=kariyer_portal;Trusted_Connection=True;ConnectRetryCount=0"
  },
  "Logging": {
    "LogLevel": {
      "Default": "Warning"
    }
  },
  "AllowedHosts": "*"
}

And I have one class MyConfig.

namespace YTPanel.Models.Model
{
    public interface ITest { string GetFolders(string param); }
    public class MyConfig: ITest
    {
        public MyConfig(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        private readonly IConfiguration Configuration;


        public string BaseMediaUrl { get; set; }
        public string FolderAnnouncement { get; set; }

        public string GetFolders(string param)
        {

            string here = Configuration["MyConfig:" + param];
            return here; 
        }
    }   
}

I want to call this class from another class

MyConfig conf;
  private  string SaveAnnouncement(IFormFile file=null,string base64=null)
        {
            string path = conf.GetFolders("FolderAnnouncement");
            string imageUrl = Guid.NewGuid().ToString();
            var mediaPath = conf.GetFolders("BaseMediaUrl");
            string extension = Path.GetExtension(file.FileName);
            var imagePath = mediaPath + path + imageUrl+extension;
            if (!string.IsNullOrEmpty(base64))
            {
                byte[] bytes = Convert.FromBase64String(base64);
                File.WriteAllBytes(imagePath, bytes);  
            }
            else
            {
                using (var fileStream = new FileStream(imagePath, FileMode.Create))
                {
                    file.CopyToAsync(fileStream);
                }
            }
            return  imageUrl+extension;

        }

I added below to ConfigureServices in Startup.

services.AddSingleton<ITest, MyConfig>();

I can't reach the data . How can I solve this problem. I want to reacj appsetting json in one class and I use this class iin any classes I want.

Thanks in advance

Answer 1

In addition to @nkosi’s answer, the Options pattern works well for this:

services.Configure<MyConfig>(configuration.GetSection(“MyConfig”));

...

public class SomeClass
{
    private MyConfig _options;

    public SomeClass(IOptions<MyConfig> options)
    {
        _options = options.Value;
    }

    private async Task<string> SaveAnnouncement(IFormFile file = null, string base64 = null)
    {
        string path = _options.FolderAnnouncement;
        ...
    }
}

There are additional variants available if you need to catch live changes to appsettings.json; see the link.

Answer 2

There really is no need to be passing IConfiguration around. The framework already has built in features that allow you to bind an object model from values in setting

Create a simple class to hold your configuration.

public class MyConfig {
    public string BaseMediaUrl { get; set; }
    public string FolderAnnouncement { get; set; }
}

Setup your class in ConfigureServices in Startup.

//bind object model from configuration
MyConfig myConfig = Configuration.GetSection("MyConfig").Get<MyConfig>();

//add it to services
services.AddSingleton(myConfig);

And inject your strongly typed configuration class where it is needed

private readonly MyConfig conf;

//Constructor
public AnnouncementService(MyConfig config) {
    this.conf = config;
}

private async Task<string> SaveAnnouncement(IFormFile file = null, string base64 = null) {
    string path = conf.FolderAnnouncement;
    string imageUrl = Guid.NewGuid().ToString();
    var mediaPath = conf.BaseMediaUrl;
    string extension = Path.GetExtension(file.FileName);
    var imagePath = mediaPath + path + imageUrl+extension;
    if (!string.IsNullOrEmpty(base64)) {
        byte[] bytes = Convert.FromBase64String(base64);
        File.WriteAllBytes(imagePath, bytes);  
    } else {
        using (var fileStream = new FileStream(imagePath, FileMode.Create)) {
            await file.CopyToAsync(fileStream);
        }
    }
    return  imageUrl+extension;
}

Note how the magic strings are no longer needed. You can access the desired configuration values via the properties.

Reference Configuration in ASP.NET Core

Answer 3

Usually you would inject your MyTest class (by interface) and use it like this:

public class AnnouncementSaver {

  private ITest config;
  public AnnouncementSaver(ITest config) {
    // inject it
    this.config = config;
  }

  private string SaveAnnouncement (IFormFile file = null, string base64 = null) {
    // use it
    config.GetFolders("FolderAnnouncement");
  }

}