[hunchentoot-devel] Processing an error outside the Hunchentoot code
What's the best to add my own error handler? I see there is some processing based on *SHOW-LISP-ERRORS-P* *SHOW-LISP-BACKTRACES-P* inside process-request function, but it doesn't allow to add a user handler of the error (or I just didn't find it). Let's say I don't want a user to see the error (only some nice reassuring message :)) and I want to be notified by an email with the backtrace. Should I go and modify the body of the process-request function (which I'll need to merge with every new release of HT) or is there a way to add my own handler outside of the Hunchentoot code? Thank you, Andrew
"Andrei Stebakov" <lispercat@gmail.com> writes:
What's the best to add my own error handler? I see there is some processing based on *SHOW-LISP-ERRORS-P* *SHOW-LISP-BACKTRACES-P* inside process-request function, but it doesn't allow to add a user handler of the error (or I just didn't find it). Let's say I don't want a user to see the error (only some nice reassuring message :)) and I want to be notified by an email with the backtrace. Should I go and modify the body of the process-request function (which I'll need to merge with every new release of HT) or is there a way to add my own handler outside of the Hunchentoot code?
I've generally found it enough to define error handlers just like I usually do in CL: (defun foo () "Display the foo page" (handler-case (... faulty code which might produce some error ...) (error () (display-a-nice-error-message)))) -- "Cut your own wood and it will warm you twice"
Right, but I'd like to have a handler if something wrong goes in request processing, when the user sees the backtrace on the screen. Andrew On 4/8/07, Yoni Rabkin Katzenell <yoni-r@actcom.com> wrote:
"Andrei Stebakov" <lispercat@gmail.com> writes:
What's the best to add my own error handler? I see there is some processing based on *SHOW-LISP-ERRORS-P* *SHOW-LISP-BACKTRACES-P* inside process-request function, but it doesn't allow to add a user handler of the error (or I just didn't find it). Let's say I don't want a user to see the error (only some nice reassuring message :)) and I want to be notified by an email with the backtrace. Should I go and modify the body of the process-request function (which I'll need to merge with every new release of HT) or is there a way to add my own handler outside of the Hunchentoot code?
I've generally found it enough to define error handlers just like I usually do in CL:
(defun foo () "Display the foo page" (handler-case (... faulty code which might produce some error ...) (error () (display-a-nice-error-message))))
-- "Cut your own wood and it will warm you twice" _______________________________________________ tbnl-devel site list tbnl-devel@common-lisp.net http://common-lisp.net/mailman/listinfo/tbnl-devel
Oh, I got it, so every hunchentoot handler should have its own error handlng procedure. I wonder if it's going to interfere with the internals of process-request function when it does the logging and other stuff? Still it would be nice to have one hook handler for all of my request handlers so I don't have to write the handler-case block for all of them. Also from my own code how do I use the get-backtrace function? Thank you, Andrew** On 4/8/07, Andrei Stebakov <lispercat@gmail.com> wrote:
Right, but I'd like to have a handler if something wrong goes in request processing, when the user sees the backtrace on the screen.
Andrew
On 4/8/07, Yoni Rabkin Katzenell <yoni-r@actcom.com> wrote:
"Andrei Stebakov" <lispercat@gmail.com> writes:
What's the best to add my own error handler? I see there is some processing based on *SHOW-LISP-ERRORS-P* *SHOW-LISP-BACKTRACES-P* inside process-request function, but it doesn't allow to add a user handler of the error (or I just didn't find it). Let's say I don't want a user to see the error (only some nice reassuring message :)) and I want to be notified by an email with the backtrace. Should I go and modify the body of the process-request function (which I'll need to merge with every new release of HT) or is there a way to add my own handler outside of the Hunchentoot code?
I've generally found it enough to define error handlers just like I usually do in CL:
(defun foo () "Display the foo page" (handler-case (... faulty code which might produce some error ...) (error () (display-a-nice-error-message))))
-- "Cut your own wood and it will warm you twice" _______________________________________________ tbnl-devel site list tbnl-devel@common-lisp.net http://common-lisp.net/mailman/listinfo/tbnl-devel
On Sun, 8 Apr 2007 11:13:27 -0400, "Andrei Stebakov" <lispercat@gmail.com> wrote:
What's the best to add my own error handler? I see there is some processing based on *SHOW-LISP-ERRORS-P* *SHOW-LISP-BACKTRACES-P* inside process-request function, but it doesn't allow to add a user handler of the error (or I just didn't find it). Let's say I don't want a user to see the error (only some nice reassuring message :)) and I want to be notified by an email with the backtrace. Should I go and modify the body of the process-request function (which I'll need to merge with every new release of HT) or is there a way to add my own handler outside of the Hunchentoot code?
If you just don't want to show Hunchentoot's error messages, you can use this one http://weitz.de/hunchentoot/#*http-error-handler* and the related variables. If you want complete control, write an around method for DISPATCH-REQUEST http://weitz.de/hunchentoot/#dispatch-request like for example this one: CL-USER 3 > (defun inversion-handler () (format nil "Result: ~A" (/ 1 (ignore-errors (parse-integer (tbnl:parameter "input")))))) INVERSION-HANDLER CL-USER 4 > (compile *) INVERSION-HANDLER NIL NIL CL-USER 5 > (setq tbnl:*default-handler* **) INVERSION-HANDLER CL-USER 6 > (defmethod tbnl:dispatch-request :around (dispatch-table) (handler-case (call-next-method) (arithmetic-error () "Oops, I can't compute that..."))) #<STANDARD-METHOD HUNCHENTOOT:DISPATCH-REQUEST (:AROUND) (T) 21DC78DB> CL-USER 7 > (tbnl:start-server :port 4242) #<HUNCHENTOOT::SERVER 21E1BD77> Etc. Cheers, Edi.
participants (3)
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Andrei Stebakov -
Edi Weitz -
Yoni Rabkin Katzenell