IHttpClientFactory and changing the HttpClient

Question

What is the best practice for changing the underlying HttpClient for a IHttpClientFactory

Here is how I create my Dependency Injection:

IServiceCollection serColl = new ServiceCollection();

serColl.AddHttpClient("tester").ConfigurePrimaryHttpMessageHandler(() =>
{
    return new HttpClientHandler()
    {
        CookieContainer = Cookies,
    };
});

var serviceProvider = serColl.BuildServiceProvider();

_HTTPClientFactory = serviceProvider.GetService<IHttpClientFactory>();

In this case Cookies holds a number of System.Net.Cookies. My question is if I need to change the cookies how should I do this?

Answer 1

Here how I solved the problem.

IServiceCollection serColl = new ServiceCollection();
serColl.AddTransient<CookieHandler>();
serColl.AddHttpClient("IHTTPRequester");
serColl.AddHttpClient("HTTPCookieClient").AddHttpMessageHandler<CookieHandler>();
var serviceProvider = serColl.BuildServiceProvider();
_HTTPClientFactory = serviceProvider.GetService<IHttpClientFactory>();

Then as HTTPCookieClient has a delegation handler I have the following

public class CookieHandler : DelegatingHandler
{
    //Everytime a client call the getasync then this is called and we then add the Cookie header to the call.
    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request,
        CancellationToken cancellationToken)
    {
        request.Headers.Add("Cookie", Your Cookie Values go here);
        
        var response = await base.SendAsync(request, cancellationToken);
        return response;
    }
}