Proper syntax for calling values from appsettings.json instead of using literal string

While there are a myriad of threads on here about this subject, the ones I looked at did not address my exact need.

ASP.NET Core 3.1 Web app:

I have a C# method that looks like this:

using System;
using System.Linq;
using System.Threading.Tasks;
using System.Collections.Generic;
using Microsoft.Data.SqlClient;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;

namespace ClientsUI.Data
{
    public class ClientsService
    {
        private readonly ClientsDbContext _context;
        private readonly IConfiguration _iconfiguration;

        public ClientsService(ClientsDbContext context, IConfiguration iconfiguration)
        {
            _context = context;
            _iconfiguration = iconfiguration;
        }
    

        public async Task<List<BillingCodes>>
        GetBillingCodesNameTestAsync()

        {
        return await _context.BillingCodes.Where(c => c.Name.Contains("Test") && c.ClientId.ToString() != "ABC123")
              .AsNoTracking()
              .ToListAsync();
        }
     }   
  }

And an appsettings.json that looks like this:

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  },

  "ConnectionStrings": {
    "DefaultConnection": "myconnectionstring"

  },

  "SqlFilters": {
    "NameFilter": "Test",
    "ClientIdFilter": "ABC123"
  }
}

In the GetBillingCodesNameTestAsync method, I need to replace “Test” and “ABC123” with a call to the appsettings.json file, something along the lines of Configuration.GetSqlFilters... which I can’t get to work properly, hence my post.

Answers:

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Method 1

I would use the strongly typed interface available in IConfiguration.

class SqlFilters {
  string NameFilter { get; set; }
  string ClientIdFilter { get; set; }
}

and then use

var sqlFilters = _iconfiguration.GetSection("SqlFilters").Get<SqlFilters>();

Accessing your variables is then as easy as accessing properties on a class (that is sqlFilters.NameFilter and sqlFilters.ClientIdFilter respectively).

Method 2

return await _context.BillingCodes.Where(c => c.Name.Contains(_iconfiguration["SqlFilters:NameFilter"]) && c.ClientId.ToString() != _iconfiguration["SqlFilters:ClientIdFilter"])
              .AsNoTracking()
              .ToListAsync();
}

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0