oracular (3) HTML::Template::FAQ.3pm.gz

NAME

       HTML::Template::FAQ - Frequently Asked Questions about HTML::Template

SYNOPSIS

       In the interest of greater understanding I've started a FAQ section of the perldocs. Please look in here
       before you send me email.

FREQUENTLY ASKED QUESTIONS

   Is there a place to go to discuss HTML::Template and/or get help?
       There's a mailing-list for discussing HTML::Template at html-template-users@lists.sourceforge.net. Join
       at:

          http://lists.sourceforge.net/lists/listinfo/html-template-users

       If you just want to get email when new releases are available you can join the announcements mailing-list
       here:

           http://lists.sourceforge.net/lists/listinfo/html-template-announce

   Is there a searchable archive for the mailing-list?
       Yes, you can find an archive of the SourceForge list here:

           http://dir.gmane.org/gmane.comp.lang.perl.modules.html-template

   I want support for <TMPL_XXX>! How about it?
       Maybe. I definitely encourage people to discuss their ideas for HTML::Template on the mailing list.
       Please be ready to explain to me how the new tag fits in with HTML::Template's mission to provide a fast,
       lightweight system for using HTML templates.

       NOTE: Offering to program said addition and provide it in the form of a patch to the most recent version
       of HTML::Template will definitely have a softening effect on potential opponents!

   I found a bug, can you fix it?
       That depends. Did you send me the VERSION of HTML::Template, a test script and a test template? If so,
       then almost certainly.

       If you're feeling really adventurous, HTML::Template is publicly available on GitHub
       (https://github.com/mpeters/html-template). Please feel free to fork it and send me a pull request with
       any changes you have.

   <TMPL_VAR>s from the main template aren't working inside a <TMPL_LOOP>! Why?
       This is the intended behavior. "<TMPL_LOOP>" introduces a separate scope for "<TMPL_VAR>s" much like a
       subroutine call in Perl introduces a separate scope for "my" variables.

       If you want your "<TMPL_VAR>"s to be global you can set the "global_vars" option when you call "new()".
       See above for documentation of the "global_vars" "new()" option.

   How can I pre-load my templates using cache-mode and mod_perl?
       Add something like this to your startup.pl:

           use HTML::Template;
           use File::Find;

           print STDERR "Pre-loading HTML Templates...\n";
           find(
               sub {
                   return unless /\.tmpl$/;
                   HTML::Template->new(
                       filename => "$File::Find::dir/$_",
                       cache    => 1,
                   );
               },
               '/path/to/templates',
               '/another/path/to/templates/'
           );

       Note that you'll need to modify the "return unless" line to specify the extension you use for your
       template files - I use .tmpl, as you can see. You'll also need to specify the path to your template
       files.

       One potential problem: the /path/to/templates/ must be EXACTLY the same path you use when you call
       "HTML::Template->new()". Otherwise the cache won't know they're the same file and will load a new copy -
       instead getting a speed increase, you'll double your memory usage.  To find out if this is happening set
       "cache_debug =" 1> in your application code and look for "CACHE MISS" messages in the logs.

   What characters are allowed in TMPL_* names?
       Numbers, letters, '.', '/', '+', '-' and '_'.

   How can I execute a program from inside my template?
       Short answer: you can't. Longer answer: you shouldn't since this violates the fundamental concept behind
       HTML::Template - that design and code should be separate.

       But, inevitably some people still want to do it. If that describes you then you should take a look at
       HTML::Template::Expr. Using HTML::Template::Expr it should be easy to write a "run_program()" function.
       Then you can do awful stuff like:

           <tmpl_var expr="run_program('foo.pl')">

       Just, please, don't tell me about it. I'm feeling guilty enough just for writing HTML::Template::Expr in
       the first place.

   What's the best way to create a <select> form element using HTML::Template?
       There is much disagreement on this issue. My personal preference is to use CGI.pm's excellent
       "popup_menu()" and "scrolling_list()" functions to fill in a single "<tmpl_var select_foo>" variable.

       To some people this smacks of mixing HTML and code in a way that they hoped HTML::Template would help
       them avoid. To them I'd say that HTML is a violation of the principle of separating design from
       programming. There's no clear separation between the programmatic elements of the "<form>" tags and the
       layout of the "<form>" tags.  You'll have to draw the line somewhere - clearly the designer can't be
       entirely in charge of form creation.

       It's a balancing act and you have to weigh the pros and cons on each side. It is certainly possible to
       produce a "<select>" element entirely inside the template. What you end up with is a rat's nest of loops
       and conditionals. Alternately you can give up a certain amount of flexibility in return for vastly
       simplifying your templates. I generally choose the latter.

       Another option is to investigate HTML::FillInForm which some have reported success using to solve this
       problem.