Getting data from configuration file, we can use something like this
appsettings.json
"ExternalApi": {
"apiUrl": "localhost:5000",
"apiClient": "client_123",
"apiSecret": "secret_123"
}
And we can read the values using this code, notice the use of magic string.
[ApiController]
public class TestController : Controller
{
private readonly IConfiguration _configuration;
public TestController(IConfiguration configuration)
{
_configuration = configuration;
}
[HttpGet("/test")]
public IActionResult Index()
{
var apiUrl = _configuration["ExternalApi:apiUrl"];
var apiClient = _configuration["ExternalApi:apiClient"];
var apiSecret = _configuration["ExternalApi:apiSecret"];
return Ok($"{apiUrl} {apiClient} {apiSecret}");
}
}
Magic strings are problematic because they can be difficult to maintain, error-prone, and can lead to issues such as typos, spelling mistakes, and inconsistency.
Instead we can create strong data type to represent the configuration
public class ExternalApiConfig
{
public string ApiUrl { get; set; }
public string ApiClient { get; set; }
public string ApiSecret { get; set; }
}
and then register the type in Program.cs
var builder = WebApplication.CreateBuilder(args);
// Add services to the container.
builder.Services.AddControllers();
// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();
const string ExternalApi = "ExternalApi";
builder.Services.Configure<ExternalApiConfig>(builder.Configuration.GetSection(ExternalApi));
var app = builder.Build();
And then we can use it in any other class like this
[ApiController]
public class TestController : Controller
{
private readonly ExternalApiConfig _externalApiConfig;
public TestController(IOptions<ExternalApiConfig> externalApiConfig)
{
_externalApiConfig = externalApiConfig.Value;
}
[HttpGet("/test")]
public IActionResult Index()
{
var apiUrl = _externalApiConfig.ApiUrl;
var apiClient = _externalApiConfig.ApiClient;
var apiSecret = _externalApiConfig.ApiSecret;
return Ok($"{apiUrl} {apiClient} {apiSecret}");
}
}
Noobgrammer 