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NAME

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

DESCRIPTION

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

General Questions

Why is the sky blue?

Something to do with refraction.

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 %]

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> writes:

    Does anyone have a quick-n-dirty approach to accessing 
    cookies from templates? 

Jonas Liljegren replies:

    [% 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 Template::Provider to Template::Provider::HTTP and use a PREFIX_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 PREFIX_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). Otherwise 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 => *STDOUT })
                                     || die $template->error();
     
    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

Can I have another cup of coffee?

No, I think you've hhhaadd ennnough alllrready.

AUTHOR

Andy Wardley <abw@kfs.org>

http://www.andywardley.com/

VERSION

2.30, distributed as part of the Template Toolkit version 2.06, released on 07 November 2001.

COPYRIGHT

  Copyright (C) 1996-2001 Andy Wardley.  All Rights Reserved.
  Copyright (C) 1998-2001 Canon Research Centre Europe Ltd.

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