[Chicken-users] http-client: distinguishing between responses 301 and 302

[Norman Gray]

Greetings.

In http-client, is there any way of distinguishing between server 
responses 301 and 302?

In test code, I want to confirm that a server is responding with the 
correct redirection code, but can't quite get there.

If I make a request using call-with-input-request and the server 
produces a redirection, then the client code follows the redirection.

If I parameterise that with (parameterize ((max-redirect-depth 0)) ...), 
then the client library doesn't follow the redirection but instead 
raises (exn http redirect-depth-exceeded).  That's almost there, except 
that the exception doesn't contain information about _which_ 
redirection, 301 or 302, prompted it.  Using (condition->list), I get

redirect-depth-exceeded: e=#<condition: (exn http 
redirect-depth-exceeded)>
list=(
(exn (arguments ("http://localhost:8081/host/";))
  (message "Maximum number of redirects exceeded")
  (location send-request))
(http)
(redirect-depth-exceeded
  (request #<request>)
  (new-uri #<URI-common: scheme=http port=8081 host="localhost" path=(/ 
"top" "host") query=() fragment=#f>)
  (uri #<URI-common: scheme=http port=8081 host="localhost" path=(/ 
"host" "") query=() fragment=#f>)))

The documentation for call-with-input-request* doesn't suggest that it 
behaves differently from call-with-input-request in this respect.  And 
although call-with-response mentions the possibility of redirects, and 
multiple calls to 'reader', it doesn't suggest that the reader procedure 
has any access to the response headers.

Is there any other way of getting this status code, or do I feel an 
enhancement request coming on?

Possibly better than this handling of redirect-depth-exceeded would be a 
parameter follow-redirects? which defaults to #t, or having 
call-with-input-request return normally (ie, without the exception) in 
the particular case that max-redirect-depth is 0.

I'm using Chicken 4, but as far as I can see, the Chicken 5 http-client 
is identical in this behaviour.

Best wishes,

Norman


--
Norman Gray  :  https://nxg.me.uk