http://www.perlmonks.org?node_id=93752


in reply to HTML::Template - Two columns?

What you want to do is possible, but requires you to use an underused feature in HTML::Template called loop_context_vars. Enabling it in the new() constructor will allow you to use the loop context variables: __FIRST__, __LAST__, __INNER__, __ODD__ inside your TMPL_IF or TMPL_UNLESS tags. To see what I mean, check out the template example at the bottom of this post.

In particular, we care about the __ODD__ variable, which will be set to true on the odd numbered passes. By testing this variable, we can print either the <tr> or </tr> tags when appropriate. Consider the following code:

#!/usr/bin/perl -w use strict; use HTML::Template; my @scores = ( { name => 'name1', score => 4 }, { name => 'name2', score => 2 }, { name => 'name3', score => 3 }, ); my $template = HTML::Template->new( filename => 'scores.tmpl', loop_context_vars => 1, ); $template->param(scores => \@scores); print $template->output;

Which loads a template that contains the following text:

<table> <TMPL_LOOP NAME='scores'> <TMPL_IF NAME='__ODD__'> <tr> </TMPL_IF> <td><TMPL_VAR NAME='name'></td><td><TMPL_VAR NAME='score'></td> <TMPL_UNLESS NAME='__ODD__'> </tr> </TMPL_UNLESS> </TMPL_LOOP> </table>

This will iterate over the @scores and print them in two columns in the table. There is only one drawback to this approach, if the @scores has an odd number of elements, the final </tr> will not be printed. This can either be solved by pushing an empty element onto the array, or creative use of the __LAST__ and __ODD__ variables together. I personally prefer the latter and try to offload presentation logic off to the template, rather than pollute the code with special exceptions.