CODEWITHSUNDEEP
c#loggingdotnet-httpclientchaininterception
BlackMatrix
BlackMatrix

Reputation: 504

Chain HttpMessageHandler for HttpClient in the correct way

How do I have to chain my HttpMessageHandlers for the HttpClient to reach my following goal.

I am using the SocketsHttpHandler as my inner HttpMessageHandler for HttpClient with cookie support. On top of the handler I wrote my own LoggingHttpHandler to log every request including the cookies.

The cookies are not present in the HttpRequestMessage and the HttpResponseMessage. They are handled by the internal CookieContainer of the SocketsHttpHandler, so I access these cookies inside my LoggingSocketsHttpHandler.

My solution is like so:

public class LoggingSocketsHttpHandler : DelegatingHandler
{       
    private readonly SocketsHttpHandler _httpHandler;           
    
    public LoggingSocketsHttpHandler(SocketsHttpHandler httpHandler)
        : base(httpHandler)
    {
         _httpHandler = httpHandler;                      
    }

    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request,
        CancellationToken cancellationToken)
    {
        LogRequestStart(request); // Access SocketsHttpHandler.CookieContainer

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

        LogRequestEnd(response); // Access SocketsHttpHandler.CookieContainer
    }
}

Works pretty fine. I am writing another HttpMessageHandler which intercepts the response if a special HTTP status code is detected.

When this occurs the HttpMessageInterceptionHandler needs to access the CookieContainer as well and makes another request. This request can be logged if the InnerHandler is a LoggingSocketsHttpHandler but should also work with the plain SocketsHttpHandler.

It seems wrong to me to search inside of those DelegatingHandlers for as long as a SocketsHttpHandler is found to get the CookieContainer. I maybe want to write my own one in the future for example. SocketsHttpHandler is sealed also.

The full pipeline would look like:

HttpMessageInterceptionHandler (1)
-> LoggingSocketsHttpHandler (2)
-> SocketsHttpHandler

where (1) and (2) needs to access the CookieContainer.

Anyone knows how to achieve this?

Upvotes: 2

Views: 2176

Answers (0)

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