Question

I have a deep-linking Silverlight RIA trying to consume a Twitter OAuth callback. The URL of the callback "page" in the RIA is:

http://example.com/RiaTestPage.aspx#callback

Twitter calls back to this URL so long as the # sign is URL encoded; so the callback url I supply to Twitter is:

http://example.com/RiaTestPage.aspx%23callback

RiaTestPage.aspx does of course exist, but when Twitter calls back to this URL, I’m getting a 404 (from the VS 2010 ASP.NET Development server)

Server Error in ‘/’ Application

The resource cannot be found.

Description: HTTP 404. The resource you are looking for (or one of its dependencies) could have been removed, had its name changed, or is temporarily unavailable. Please review the following URL and make sure that it is spelled correctly.

Requested URL: /RiaTestPage.aspx#callback

Although the # sign has been correctly decoded in the error message above, the 404 seems to be the result of the encoded # sign. If I manually change the callback url that caused the 404,

http://example.com/RiaTestPage.aspx%23callback

to this:

http://example.com/RiaTestPage.aspx#callback

The callback page in the RIA loads normally. Why am I receiving a 404 in this situation?

Answer 1

You get a 404 error because the #callback part is not part of the URL. It’s a bookmark that is used by the browser, and it’s never sent in the request to the server. If you encode the hash, it becomes part of the file name instead, and there is no file named RiaTestPage.aspx#callback.