CODEWITHSUNDEEP
c#asp.net-coredependency-injection.net-coredotnet-httpclient
Zinov
Zinov

Reputation: 4119

How to pass/inject more than one HttpClient parameter to a typed HttpClientClass?

I want to register a typed HttpClient as here Microsoft docs. Basically, the approach should be

services.AddHttpClient();

normally the pattern of these classes receive only the HttpClient class as a parameter and you implement the logic to call the endpoint. In my case, I need to use 2 HttpClient inside my MyHttpClient, one that pings the endpoint and the other one that talks with an IdentityProvider to discover the refreshEndpoints to refresh my cookies.

public class MyHttpClient : IMyHttpClient
{
    public MyHttpClient (HttpClient httpClient, 
                         HttpClient refreshHttpClient)
    {
    }
}

If I am trying to resolve from a controller an IMyHttpClient, I get an error saying it can't resolve an HttpClient.

In the GitHub code on line 43 AddHttpClient you can see that is calling DefaultTypedHttpClientFactory. If you go to the implementation of the DefaultTypedHttpClientFactory implementation you will notice that is a generic type. And when it calls CreateClient it only passes one parameter to the constructor on line 39.

The only workaround I am seeing here is to not create a typed client and register a normal class that receives an IHttpClientFactory and create and configure my clients on the fly, not as typed. Any other idea?

Upvotes: 4

Views: 5231

Answers (1)

Chris Pratt
Chris Pratt

Reputation: 239440

You can't. You'll either need to inject another service layer or IHttpClientFactory directly

Another service

public class MyRefreshClient
{
    private readonly HttpClient _httpClient;

    public MyRefreshClient(HttpClient httpClient)
    {
        _httpClient = httpClient;
    }

    ...
}

public class MyHttpClient : IMyHttpClient
{
    private readonly HttpClient _httpClient;
    private readonly MyRefreshClient _refreshClient;

    public MyHttpClient(HttpClient httpClient, MyRefreshClient refreshClient)
    {
        _httpClient = httpClient;
        _refreshClient = refreshClient;
    }
}

Then:

services.AddHttpClient<MyRefreshClient>(c => { ... });
services.AddHttpClient<MyHttpClient>(c => { ... });

Inject IHttpClientFactory (and use named clients):

public class MyHttpClient : IMyHttpClient
{
    private readonly HttpClient _httpClient;
    private readonly HttpClient _refreshClient;

    public MyHttpClient(IHttpClientFactory httpClientFactory)
    {
        _httpClient = httpClientFactory.CreateClient("MyHttpClient");
        _refreshClient = httpClientFactory.CreateClient("MyRefreshClient");
    }
}

Then:

services.AddHttpClient("MyHttpClient", c => { ... });
services.AddHttpClient("MyRefreshClient", c=> { ... });

Upvotes: 7

Related Questions