Fixed header and base url definition to be used in the whole program for Restsharp

Question

I have some commonization operations for httpclient, I want to apply these operations in restsharp client.

I am sharing sample httpclient codes

1.Startup

The process of registering the service as a container in the startup file Like here, I was able to subscribe to di container and customize the httpclient, I didn't have to define baseapiurl over and over in the whole service. is it possible to implement this method in restsharp

 services.AddHttpClient<ICatalogService, CatalogService>(opt =>
        {
            opt.BaseAddress = new Uri($"{serviceApiSettings.GatewayBaseUri}/{serviceApiSettings.Catalog.Path}");
        }).AddHttpMessageHandler<ClientCredentialTokenHandler>();

2.ClientCredentialTokenHandler.cs

   public class ClientCredentialTokenHandler:DelegatingHandler
    {
        private readonly IClientCredentialTokenService _clientCredentialTokenService;

        public ClientCredentialTokenHandler(IClientCredentialTokenService clientCredentialTokenService)
        {
            _clientCredentialTokenService = clientCredentialTokenService;
        }

        protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
        {
            request.Headers.Authorization = new AuthenticationHeaderValue("Bearer",await _clientCredentialTokenService.GetToken());

            var response = await base.SendAsync(request,cancellationToken);

            if (response.StatusCode==System.Net.HttpStatusCode.Unauthorized)
            {
                throw new UnAuthorizeException();
            }
            return response;
        }
  }

This structure saves me from duplication of code when making requests to external services from every httpclient. Is a similar solution possible for RestClient?

Answer 1

Yes, you can add default parameters (not just headers) and specify the base address for RestClient as well.

var client = new RestClient(baseUrl).AddDefaultHeader(key, value);

Here, AddDefaultHeader is a wrapped around AddDefaultParameter, which accepts any parameter type except BodyParameter.

Concerning delegating handlers, you can either use one of the RestClient constructors, which accepts an instance of HttpMessageHandler, or a ConfigureMessageHandler property of RestClientOptions. It is described in the documentation.