[hunchentoot-devel] Backtrace display + idea for "representations"

[Jochen Schmidt]

Hans,

As outlined before - *break-on-signals* is not a good solution. Not  
all conditions are errors or useful break points. If we really have to  
fallback to ANSI CL means for that purpose, wrapping a handler-bind  
like in Andreas' Solution is better - I use something similar in my  
code (Actually I do handle all conditions in my handlers now, because  
I didn't get hunchentoots error handling to do what I wanted).  
Documentation may help, or not; some clear protocols would be  
perfect :-)

Hunchentoot evolved really well towards 1.0. I really appreciate the  
extensibility one now gets through some clearer protocols (task- 
managers, request-/reply-class a. s. o.). I still see some open  
problems though. Hunchentoot completely misses the concept of a  
"representation" - instead it uses either strings or octet-streams  
directly in an ad hoc way. Perhaps it would be a good idea to abstract  
this underlying representations using a small set of extensible  
representation classes? Something like:

representation
       |
     / | \
     | |  string-representation
     | |
     | file-representation
     |
stream-representation

A handler would then not either return a string or write itself into  
the stream one gets from send-headers, but it would generate (or  
select) a representation object and hunchentoot handles this  
automatically.

ciao,
Jochen

--
Jochen Schmidt

Am 03.09.2009 um 08:45 schrieb Hans Hübner <hans.huebner at gmail.com>:

> We have removed the backtrace support from Hunchentoot because we
> wanted to get rid of all non-essential system dependencies.  For
> interactive debugging, the *BREAK-ON-SIGNALS* special variable can
> (should) be used, it can do what the presented acceptor subclass can
> do.  If you really need backtraces in your log files, the
> trivial-backtrace [2] library may be useful.
>
> It would be useful to have a section on debugging in the manual.
>
> -Hans
>
> [1] http://www.ai.mit.edu/projects/iiip/doc/CommonLISP/HyperSpec/Body/var_stbreak-on-signalsst.html
> [2] http://common-lisp.net/project/trivial-backtrace/
>
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