February 2005 - tbnl-devel@common-lisp.net

[tbnl-devel] arbitrary per-request data?
by Zach Beane 17 Sep '05

17 Sep '05

I have an application that has a notion of a current user that is lazily established on a per-request basis. For now, I have been returning a handler that is really a lambda wrapping a real handler that lexically binds the special *current-user*: (defun page-handler (request) (multiple-value-bind (handler foundp) (gethash (script-name request) *handlers*) (when foundp (lambda () (let ((*current-user* *current-user-local-unbound-value*)) (funcall handler)))))) But it occurred to me that there is already the *request* structure. Would it make sense to be able to have a table of arbitrary keys and values in the request structure for application use? I was thinking of an accessor like this: request-data key &optional (request *request*) => value, foundp Then I could write CURRENT-USER something like: (defun current-user () (multiple-value-bind (value foundp) (request-data 'user) (if foundp value (setf (request-data 'user) (cookie-user))))) Right now it's a bit messier than that. What do you think? If this seems reasonable I can work out and submit a patch. Zach

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Re: [tbnl-devel] a problem while installing..
by Jason Wang 06 Mar '05

06 Mar '05

hi, i'm back again... aftering trying to get Fedora Core 3 to work for about a week, tired of trying for now, i'll get back at it when i learn more lisp :D.. so now i have taken ur earlier advice in downloading trial version of Allegro CL, do you know how i can integrate into my lisp in a box? since you have said it's possible, is it possible in the trial version? thanks alot! -- www.programer.name - my own personal blog : )

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[tbnl-devel] Handling HTTP errors
by Stefan Scholl 01 Mar '05

01 Mar '05

Hi! Function send-output in modlisp.lisp handles the response for different return codes. E. g. there's a "The requested URL ~A was not found on this server." for the 404 (+http-not-found+). How about letting the user change this behavior? One could explain the error to the user. Maybe in another language. Or think of all the funny 404 games. Remember the SGI babies? There could be different approaches: * Simple hash A hash with error code as key and handler as value. + Easy to implement + Can handle all errors (thrown by handlers _and_ when no dispatcher is found) - Not very flexible. Just checks for the code and not for any request data. * Error dispatcher Like the normal dispatcher, but checking for the right error output handler. + Can handle all errors (thrown by handlers _and_ when no dispatcher is found) + Flexible. Can check the code _and_ request data. - A bit big. The same effort like handling normal requests. * Handler outputs itself and signals that A handler wants to return a 404. It constructs the output string and signals the fact that there's no need for TBNL to build the HTML for the output. + Easy to implement(? clean?) + Flexible - Can't handle all errors. (No handler found? Then the code won't be executed.) Regards, Stefan

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[tbnl-devel] Re: problems compiling TBNL 0.3.11 in SBCL 0.8.19
by Edi Weitz 27 Feb '05

27 Feb '05

Hi John! [Cc to mailing list.] On Fri, 25 Feb 2005 23:54:42 -0800, John Wiseman <jjwiseman(a)yahoo.com> wrote: > Hi, Edi. I just wanted to let you know that I had some trouble > compiling TBNL 0.3.11 in SBCL 0.8.19: > > ; /usr/local/lib/sbcl/site/tbnl-0.3.11/test/test.fasl written > ; compilation finished in 0:00:02 > > debugger invoked on a SB-INT:STREAM-DECODING-ERROR in thread 1771: > decoding error on stream > #<FILE-STREAM for "file > \"/usr/local/lib/sbcl/site/tbnl-0.3.11/test/fz.jpg\"" {48E6BF81}> > (:EXTERNAL-FORMAT :UTF-8): > the octet sequence (255 216 255 224) cannot be decoded. > > You can type HELP for debugger help, or (SB-EXT:QUIT) to exit from SBCL. > > restarts (invokable by number or by possibly-abbreviated name): > 0: [ATTEMPT-RESYNC ] Attempt to resync the stream at a character > boundary > and continue. > 1: [FORCE-END-OF-FILE] Force an end of file. > 2: [RETRY ] Retry performing #<ASDF:LOAD-OP NIL > {48002121}> on > #<ASDF:CL-SOURCE-FILE "test" {48006339}>. > 3: [ACCEPT ] Continue, treating #<ASDF:LOAD-OP NIL > {48002121}> on > #<ASDF:CL-SOURCE-FILE "test" {48006339}> as > having > been successful. > 4: [RETRY ] Retry installation > 5: [ABORT ] Reduce debugger level (leaving debugger, > returning to > toplevel). > 6: [TOPLEVEL ] Restart at toplevel READ/EVAL/PRINT loop. > (SB-INT:STREAM-DECODING-ERROR > 2 > #<FILE-STREAM for "file > \"/usr/local/lib/sbcl/site/tbnl-0.3.11/test/fz.jpg\"" {48E6BF81}> > (255 216 255 224))[:EXTERNAL] Looks like SBCL is expecting an UTF-8 encoded stream. But this is a JPG file and should be read as a sequence of octets. I'm not familiar with SBCL's new Unicode facilities, I guess you have to provide the right external format when opening the stream. TBNL on the SBCL/Mac combo won't work, though, because TBNL needs threads. Cheers, Edi.

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[tbnl-devel] Weird problem with cookies and startup
by Bob Hutchison 27 Feb '05

27 Feb '05

Hi, I've been using TBNL for a few weeks and am encountering some strange behaviour when sessions time out. Specifically, once a session times out I start getting multiple cookies written to the browser -- as the user navigates around the site the cookie, and so the session, changes. I am wondering if this is a known problem. If so, maybe some advice. Otherwise, I'll try to isolate the problem better so I can provide a more precise description of what is happening. There is another problem for which I have no explanation: when the lisp system is first started up it takes several attempts to load the page before the page is loaded (it isn't getting as far as the lisp program I think). Same thing: if this is familiar, maybe some advice... otherwise I'll try to describe the problem better. I'm using Lispworks 4.4 professional on OS/X (10.3.8) using what ever the current versions of Apache 1.x (for OS/X) and mod_lisp. Other that that, TBNL works beautifully. Very nice. Cheers, Bob ---- Bob Hutchison -- blogs at <http://www.recursive.ca/hutch/> Recursive Design Inc. -- <http://www.recursive.ca/>

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[tbnl-devel] Re: TBNL Example
by Edi Weitz 25 Feb '05

25 Feb '05

Hi Lukas! Please use the mailing list for further questions and comments. Thanks. On Fri, 25 Feb 2005 11:55:18 +0000, Lukas Trejtnar <l.trejtnar(a)open.ac.uk> wrote: > I have been using the mod_lisp module for a couple of years where I > written a Lisp counterpart myself. I didn't implement a > session/cookie management and because of that would like to start > using your TBNL library. It looks like a great piece of work. Thanks... :) > I was reading through a documentation of TBNL and not sure about > testing session expiration. My scenario would be a login page where > a user would authorise and a new session would be created, then a > user would browse pages and the session would be every time checked > if it didn't expire. If it did, a user would be redirected to the > login page. It's a standard scenario, I guess. Here comes my > question. > > How do I hook up 'session expires' to the authorisation? After > reading the documentation, I assume, that I would modify a value of > *session-removal-hook* to redirection function. Is it how you > designed it? Do you have any practical examples? I'm not sure I fully understand your question, or maybe we're talking about different things. If you're using TBNL's session facility you don't have to keep track of session expiry yourself - TBNL will do that for you. If you have the same idea about session expiry that TBNL has, that is. Each session object has a slot which holds the number of seconds this session is valid without user interaction - see the docs for SESSION-MAX-TIME.[1] If the user is idle longer than this period then the session will be automatically invalidated. This doesn't necessary mean that the session object is garbage-collected at this point but it /does/ mean that you can't access the session object anymore, i.e. TBNL will behave as if there had never been a session object. In other words: Usually you shouldn't have to care about *SESSION-REMOVAL-HOOK*, it's a finalizer kind of thing that's rarely useful. Now, sessions aren't necessarily related to authorization but they can be used for it. One approach that I've been using is the following: After a successful login the server stores some kind of object in the session which "proofs" that the user is authorized, like this: (setf (session-value 'user) (make-foo-object)) Then I can wrap all pages requiring authorization into a macro that looks like this (untested): (defmacro with-authorization (&body body) `(cond ((is-foo-object (session-value 'user)) ,@body) (t (redirect "/login-page.html")))) Does that answer your question? Cheers, Edi. PS: I'll be away for two days so I probably won't answer before monday. [1] Just noticed that the default value (30 minutes) isn't documented and *SESSION-MAX-TIME* isn't exported. This'll be fixed in a future release.

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[tbnl-devel] New version 0.3.11
by Edi Weitz 21 Feb '05

21 Feb '05

Changelog: Version 0.3.11 2005-02-21 Added ability to access raw post data (suggested and coded by Zach Beane) Download: <http://weitz.de/files/tbnl.tar.gz> Cheers, Edi.

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[tbnl-devel] verbatim post parameter access?
by Zach Beane 21 Feb '05

21 Feb '05

I'm implementing a PayPal IPN handler in TBNL. The process works like this: 1. paypal receives a payment for your account 2. paypal POSTs the details of the transaction to an URL you specify, e.g. http://tbnlhosting.com/xach/process-ipn 3. you POST the body of their POST back to a paypal URL, with one additional variable appended 4. paypal replies to the POST with "VERIFIED" or "INVALID" Is it possible to get the verbatim body of a POST request with TBNL? I noticed there's a header-in value of "content-stream", but it's not documented. Zach

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[tbnl-devel] Problem with ppc/sbcl
by chris＠austin-lane.net 08 Feb '05

08 Feb '05

I can't get TBNL to stay responsive reliably on SBCL/ppc (which is a no-threads platform). Among other things, it will block in read-line (get-apache-command) when the connection from apache has gone away. Hitting Control-C interrupts the read and pushes the process back to the place where it's accepting the new connection from apache. (Using mod_lisp2). Does anyone have experience with this platform? Is it expected to work? Thanks, --Chris -- Chris Austin-Lane - +1-301-270-6524 - chris(a)austin-lane.net The #6 Fundamental Truth: It is easier to move a problem around (for example, by moving the problem to a different part of the overall network architecture) than it is to solve it. (RFC 1925)

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[tbnl-devel] a problem while installing..
by Jason Wang 05 Feb '05

05 Feb '05

hi, i'm using win32 with apache2 installed.. i try to start tbnl (loading went fine..), using (tbnl:start-tbnl), and it just stops, give me a new line, and stops, when i type an enter, it give me a new line, on the bottom, it says pipeline request... (swank: listener-eval " "), then stops again.. is this normal? When i try to load the test page from the web browser (http://localhost/tbnl/test/test.lisp) it gave me a server error Server error! The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there was an error in a CGI script. If you think this is a server error, please contact the webmaster. i put in the lines to httpd.config: LispServer 127.0.0.1 3000 "tbnl" <Location /tbnl> SetHandler lisp-handler </Location> anyone know what's happening? -- www.programer.name - my own personal blog : )

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