Adding a cookie to DocumentRequest - cookies

Question

Using AngleSharp v 0.9.9, I'm loading a page with OpenAsync which sets a bunch of cookies, something like:
var configuration = Configuration.Default.WithHttpClientRequester().WithCookies();
var currentContext = BrowsingContext.New(configuration);
// ....
var doc = context.OpenAsync(url, token);
This works fine and I can see the cookies have been set. For example, I can do this:
var cookieProvider = currentContext.Configuration.Services.OfType<ICookieProvider>().First() as MemoryCookieProvider;
And examine it in the debugger and see the cookies in there (for domain=.share.state.nm.us)
Then I need to submit a post:
var request = new DocumentRequest(postUrl);
request.Method = HttpMethod.Post;
request.Headers["Content-Type"] = "application/x-www-form-urlencoded";
request.Headers["User-Agent"] = userAgent;
//...
Which eventually gets submitted:
var download = loader.DownloadAsync(request);
And I can see (using Fiddler) that it's submitting the cookies from the cookieProvider.
However, I need to add a cookie (and possible change the value in another) and no matter what I try, it doesn't seem to include it. For example, I do this:
cookieProvider.Container.Add(new System.Net.Cookie()
{
Domain = ".share.state.nm.us",
Name = "psback",
Value = "somevalue",
Path = "/"
});
And again I can examine the cookieProvider in the debugger and see the cookie I set. But when I actually submit the request and look in fiddler, the new cookie isn't included.
This seems like it should be really simple, what is the correct way to set a new cookie and have it included in subsequent requests?

Answer 1

I think there are two potential ways to solve this.
either use document.Cookie for setting a new cookie (would require an active document that already is at the desired domain) or
Use a Filter for getting / manipulating the request before its send. This let's you really just change the used cookie container before actually submitting.
The Filter is set in the DefaultLoader configuration. See https://github.com/AngleSharp/AngleSharp/blob/master/src/AngleSharp/ConfigurationExtensions.cs#L152.