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use strict; use warnings; package HTML::Template::FAQ; # ABSTRACT: Frequently Asked Questions about HTML::Template use Carp (); Carp::confess "you're not meant to use the FAQ, just read it!"; 1; __END__ =pod =head1 NAME HTML::Template::FAQ - Frequently Asked Questions about HTML::Template =head1 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. =head1 FREQUENTLY ASKED QUESTIONS =head2 Is there a place to go to discuss HTML::Template and/or get help? There's a mailing-list for discussing L<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 =head2 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 =head2 I want support for <TMPL_XXX>! How about it? Maybe. I definitely encourage people to discuss their ideas for L<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 L<HTML::Template> will definitely have a softening effect on potential opponents! =head2 I found a bug, can you fix it? That depends. Did you send me the VERSION of L<HTML::Template>, a test script and a test template? If so, then almost certainly. If you're feeling really adventurous, L<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. =head2 <TMPL_VAR>s from the main template aren't working inside a <TMPL_LOOP>! Why? This is the intended behavior. C<< <TMPL_LOOP> >> introduces a separate scope for C<< <TMPL_VAR>s >> much like a subroutine call in Perl introduces a separate scope for C<my> variables. If you want your C<< <TMPL_VAR> >>s to be global you can set the C<global_vars> option when you call C<new()>. See above for documentation of the C<global_vars> C<new()> option. =head2 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 C<return unless> line to specify the extension you use for your template files - I use F<.tmpl>, as you can see. You'll also need to specify the path to your template files. One potential problem: the F</path/to/templates/> must be B<EXACTLY> the same path you use when you call C<< 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 C<cache_debug => 1> in your application code and look for "CACHE MISS" messages in the logs. =head2 What characters are allowed in TMPL_* names? Numbers, letters, '.', '/', '+', '-' and '_'. =head2 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 L<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 L<HTML::Template::Expr>. Using L<HTML::Template::Expr> it should be easy to write a C<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 L<HTML::Template::Expr> in the first place. =head2 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 L<CGI.pm>'s excellent C<popup_menu()> and C<scrolling_list()> functions to fill in a single C<< <tmpl_var select_foo> >> variable. To some people this smacks of mixing HTML and code in a way that they hoped L<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 C<< <form> >> tags and the layout of the C<< <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 C<< <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 L<HTML::FillInForm> which some have reported success using to solve this problem.