faq(3)

NAME

Template::FAQ - Frequently Asked Questions about the Tem
plate Toolkit

DESCRIPTION

This is the Frequently Asked Questions list for the Tem
plate Toolkit. More accurately, it's a very thin place
holder for where the FAQ will soon be.

Template Toolkit Language

Why doesn't [% a = b IF c %] work as expected?

Because the parser interprets it as: [% a = (b IF c) %]
Do this instead:: [% SET a = b IF c %]
If I'm using TT to write out a TT template, is there a good way to escape [% and %]?
You can do this:: [% stag = "["
etag = "%]"; %]
and then:: [% stag; 'hello'; etag %]
Or something like:: [% TAGS [- -] %]
[- INCLUDE foo -] # is a directive
[% INCLUDE foo %] # not a directive, just plain text,; passed through

Plugins

How do I get the Table plugin to order data across rather than down?

Order the data into rows:: Steve Karen Jeff
Brooklyn Nantucket Fairfax
NY MA VA
[% USE table(data, rows=3) %]
Then ask for each column: [% FOREACH column = table.cols %]
And then print each item in the column going across the output rows: [% FOREACH item = column %]
<td>[% item %]</td>; [% END %]
Accessing Cookies
Jeff Boes <boes@nexcerpt.com> asks:: Does anyone have a quick-n-dirty approach to accessing
cookies from templates?
Jonas Liljegren answers:: [% USE CGI %]; <p>The value is [% CGI.cookie('cookie_name') | html %]

Extending the Template Toolkit

Can I serve templates from a database?

Short answer: yes, Chris Nandor has done this for Slash.
You need to subclass Template::Provider. See the mailing
list archives for further info.

Can I fetch templates via http?

To do the job properly, you should sublcass Tem plate::Provider to Template::Provider::HTTP and use a PRE FIX_MAP option to bind the 'http' template prefix to that particular provider (you may want to go digging around in the Changes file around version 2.01 for more info on PRE FIX_MAP - it may not be properly documented anywhere else...yet!). e.g. (untested due to lack of existing HTTP Provider - patches welcome!).: use Template::Provider::HTTP;; my $file = Template::Provider( INCLUDE_PATH => [...]; );
my $http = Template::Provider::HTTP->new(...);
my $tt2 = Template->new({
LOAD_TEMPLATES => [ $file, $http ],
PREFIX_MAP => {
file => '0', # file:foo.html
http => '1', # http:foo.html
default => '0', # foo.html =>

file:foo.html

}; });
Now a template specified as:: [% INCLUDE foo %]
will be served by the 'file' provider (the default). Oth erwise you can explicitly add a prefix:: [% INCLUDE file:foo.html %]
[% INCLUDE http:foo.html %]
[% INCLUDE http://www.xyz.com/tt2/header.tt2 %]
This same principal can be used to create a DBI template provider. e.g.: [% INCLUDE dbi:foo.html %]
But similarly, alas, we don't yet have a DBI provider as part of the Template Toolkit. There has been some talk on the mailing list about efforts to develop DBI and/or HTTP providers but as yet no-one has stepped forward to take up the challenge...
In the mean time, Craig's post from the mailing list has some useful pointers on how to acheive this using existing modules:: To: Adam Theo <adamtheo@theoretic.com>
From: Craig Barratt <craig@arraycomm.com>
Date: Fri, 18 May 2001 17:06:59 -0700; > i was wondering if there is anyway to fetch a file; using http:// or
> ftp:// and include that?; Here's one way. Set the LOAD_PERL option:

use Template;

my $template = Template->new({
LOAD_PERL => 1

});
$template->process("example.tt", { stdout => *STD

OUT })

|| die $template->er

ror();
and then use LWP::UserAgent and HTTP::Request:: [%
USE ua = LWP.UserAgent;
ua.proxy("http", "http://your_proxy/");
USE req = HTTP.Request("GET",

"http://www.cpan.org");
ua.request(req).content;; -%]
For FTP use Net::FTP:: [%
USE ftp = Net.FTP("ftp.cpan.org");
x = ftp.login("anonymous", "me@here.there");
x = ftp.cwd("/");
x = ftp.get("welcome.msg", stdout);
x = ftp.quit;; -%]
Normally ftp.get would write the file into the current
directory. Instead we pass stdout as a second argument so that it
is written to stdout. We set stdout to STDOUT in the variables
we pass to process.
Craig

Miscellaneous

How can I configure variables on a per-request basis?

One easy way to acheive this is to define a single
PRE_PROCESS template which loads in other configuration
files based on variables defined or other conditions.

For example, my setup usually looks something like this:: PRE_PROCESS => 'config/main'
config/main:: [% DEFAULT style = 'text'
section = template.section or 'home';
PROCESS config/site: + config/urls
+ config/macros
+ "config/style/$style"
+ "config/section/$section"
+ ...
%]
This allows me to set a single 'style' variable to control which config file gets pre-processed to set my various style options (colours, img paths, etc). For example:
config/style/basic:: [% style = {
name = style # save existing 'style' var as

'style.name'

# define various other style variables....
col = {
back => '#ffffff'
text => '#000000'
# ...etc...

}

logo = {

# ...etc...

}

# ...etc...; }
%]
Each source template can declare which section it's in via a META directive:: [% META
title = 'General Information'
section = 'info'; %]; ...
This controls which section configuration file gets loaded to set various other variables for defining the section title, menu, etc.
config/section/info:: [% section = {
name = section # save 'section' var as

'section.name'
title = 'Information'
menu = [ ... ]
# ...etc...; }
%]
This illustrates the basic principal but you can extend it to perform pretty much any kind of per-document initiali sation that you require.

AUTHOR

Andy Wardley <abw@andywardley.com>

<http://www.andywardley.com/|http://www.andywardley.com/>

VERSION

2.54, distributed as part of the Template Toolkit version
2.08, released on 30 July 2002.

COPYRIGHT

Ltd.
This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

docs.sk

comprehensive documentation repository

In section