Thanks for the FAQ link. I did not see that before.

I am already aware that I can print the template name this way,
what I try to learn is how I can have this happen at every invocation of any template / include
_without_ having to add a print statement to each.

In many web-centric templating systems there is a config setting to make this happen.
I fail to find such a setting or a feasible workaround for TT.

I hope I understand what you want ... just to avoid actually typing the tags? Because if they are going to be in the outputted HTML file, they are going to get printed somehow, by somebody :-)

One thing to consider is that you can use TT2 to make TT2 templates ... So your default template for making an .html.tmpl could include the TT2 tags to display the debug info you want ...

Or, if you make your templates by hand, since the text strings are going to be at the top and bottom of every template file you have, it doesn't seem necessary for TT2 to magically insert them. Instead, you could have the lines pre-inserted in the actual text files you create for templates, for example by using a macro in vim:

# in ~/.vimrc
" Set up templates for new files
autocmd BufNewFile * 0r ~/.vim/templates/%:e.template
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and then

# in ~/.vim/templates/tmpl.template
<!-- Start output from [% component.name %] -->


<!-- End output from [% component.name %] -->
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and then whenever you open a new file in vim it will have the tags pre-inserted.

Hope this is close to the mark of what you needed!

Although i am quite sure this is possible (see Template::Provider) you probably do not want output these comments in your production environment as you will give clues away to any would-be attackers. Instead, why not just grep or ack for the markup in question? I have found this to be a very workable solution for tracking down templates. No need to add more code to your base.

UPDATE: this might work for you, but i still recommend using grep or ack:

use strict;      
use warnings;                
use Data::Dumper;            
use Template;                

my $file = 'src/greeting.html';
my $vars = { message  => "Hello World\n" };

my $tt = Template->new;
$tt->process($file, $vars);

my ($found) = keys %{ $tt->{SERVICE}{CONTEXT}{LOAD_TEMPLATES}[0]->{LOO
+KUP} };
print "$found\n";
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L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

Thanks for the assist.

To grep for parts of the markup is possible, but a lot slower
when compared to just reading the template names inline.

Basically, what I'd hope to see is something like this:

...
<!-- BEGIN OUTPUT from 'template/en/bug/bug_edit.html.tmpl' -->
<ul>
  <li># lots of markup ....</li>
</ul>
<!-- END OUTPUT from 'template/en/bug/bug_edit.html.tmpl' -->
<!-- BEGIN OUTPUT from 'template/en/global/footer.html.tmpl' -->
...
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Strictly for development of course, none of this clutter would get anywhere near production ;-)

If you are lucky you can add PROCESS to the Template config in Bugzilla/Template.pm and it will run when ever you put in there whenever it processes a template.

    PROCESS  => 'tricksy',
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and make templates/en/default/tricksy

<!-- [% template.title %] -->
[% PROCESS $template %]
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If you are not lucky, then you will need to sub-class Template::Service and set $Template::Config::SERVICE = $mysubclass; before the Template is instantiated.

It gives you output like this in your HTML:

    <!-- TIMER START: L1 process mainmenu/mainmenu.tt -->
    <!-- TIMER START: L2 include mainmenu/cssindex.tt -->
    <!-- TIMER START: L3 process mainmenu/cssindex.tt -->
    <!-- TIMER END:   L3 process mainmenu/cssindex.tt (17.279 ms) -->
    <!-- TIMER END:   L2 include mainmenu/cssindex.tt (17.401 ms) -->

    ....

    <!-- TIMER END:   L3 process mainmenu/footer.tt (3.016 ms) -->
    <!-- TIMER END:   L2 include mainmenu/footer.tt (3.104 ms) -->
    <!-- TIMER END:   L1 process mainmenu/mainmenu.tt (400.409 ms) -->
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I know you didn't ask for timings, but at least it shows nesting levels.