[Templates] basic question about logging from TT

[Andy Wardley]

markd wrote:
> I know I can do:
> 
>  [% PERL %]
>    print STDERR "message";
>  [% END %]
> 
> But tedious (and presumably inefficient?)

I usually do something like this in a PRE_PROCESS config file:

    [% IF debug;
         MACRO debug_msg(text)
           FILTER stderr; "  # $text\n"; END;
       ELSE;
         debug_msg = '';
       END;
    %]

I use a 'debug' flag (set in my ttree config file or in variables passed 
in from my Perl code/Apache handle) to enable/disable debugging en 
masse.  If debugging is on then the debug_msg() MACRO is defined to 
print its argument to stderr (via the stderr FILTER), otherwise it's a 
nullup.

Then in my templates I write:

    [% debug_msg("Hello World") %]

HTH
A