NAME

Template::Plugin::Cycle - Cyclically insert into a Template from a sequence of values

SYNOPSIS

[% USE cycle('row', 'altrow') %]

<table border="1">
  <tr class="[% class %]">
    <td>First row</td>
  </tr>
  <tr class="[% class %]">
    <td>Second row</td>
  </tr>
  <tr class="[% class %]">
    <td>Third row</td>
  </tr>
</table>





###################################################################
# Alternatively, you might want to make it available to all templates
# throughout an entire application.

use Template::Plugin::Cycle;

# Create a Cycle object and set some values
my $Cycle = Template::Plugin::Cycle->new;
$Cycle->init('normalrow', 'alternaterow');

# Bind the Cycle object into the Template
$Template->process( 'tablepage.html', class => $Cycle );





#######################################################
# Later that night in a Template

<table border="1">
  <tr class="[% class %]">
    <td>First row</td>
  </tr>
  <tr class="[% class %]">
    <td>Second row</td>
  </tr>
  <tr class="[% class %]">
    <td>Third row</td>
  </tr>
</table>

[% class.reset %]
<table border="1">
  <tr class="[% class %]">
    <td>Another first row</td>
  </tr>
</table>





#######################################################
# Which of course produces

<table border="1">
  <tr class="normalrow">
    <td>First row</td>
  </tr>
  <tr class="alternaterow">
    <td>Second row</td>
  </tr>
  <tr class="normalrow">
    <td>Third row</td>
  </tr>
</table>

<table border="1">
  <tr class="normalrow">
    <td>Another first row</td>
  </tr>
</table>

DESCRIPTION

Sometimes, apparently almost exclusively when doing alternating table row backgrounds, you need to print an alternating, cycling, set of values into a template.

Template::Plugin::Cycle is a small, simple, and hopefully DWIM solution to these sorts of tasks.

It can be used either as a normal Template::Plugin, or can be created directly and passed in as a template argument, so that you can set up situations where it is implicitly available in every page.

METHODS

new [ $Context ] [, @list ]

The new constructor creates and returns a new Template::Plugin::Cycle object. It can be optionally passed an initial set of values to cycle through.

When called from within a Template, the new constructor will be passed the current Template::Context as the first argument. This will be ignored.

By doing this, you can use it both directly, AND from inside a Template.

init @list

If you need to set the values for a new empty object, of change the values to cycle through for an existing object, they can be passed to the init method.

The method always returns the '' null string, to avoid inserting anything into the template.

elements

The elements method returns the number of items currently set for the Template::Plugin::Cycle object.

list

The list method returns the current list of values for the Template::Plugin::Cycle object.

This is also the prefered method for getting access to a value at a particular position within the list of items being cycled to.

[%# Access a variety of things from the list %]
The first item in the Cycle object is [% cycle.list.first %].
The second item in the Cycle object is [% cycle.list.[1] %].
The last item in the Cycle object is [% cycle.list.last %].

next

The next method returns the next value from the Cycle. If the end of the list of valuese is reached, it will "cycle" back the first object again.

This method is also the one called when the object is stringified. That is, when it appears on its own in a template. Thus, you can do something like the following.

<!-- An example of alternate row classes in a table-->
<table border="1">
  <!-- Explicitly access the next class in the cycle -->
  <tr class="[% rowclass.next %]">
    <td>First row</td>
  </tr>
  <!-- This has the same effect -->
  <tr class="[% rowclass %]">
    <td>Second row</td>
  </tr>
</table>

value

The value method is an analogy for the next method.

reset

If a single Template::Plugin::Cycle object is to be used it multiple places within a template, and it is important that the same value be first every time, then the reset method can be used.

The reset method resets the Cycle, so that the next value returned will be the first value in the Cycle object.

SUPPORT

Bugs should be submitted via the CPAN bug tracker, located at

http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Template-Plugin-Cycle

For other issues, or commercial enhancement or support, contact the author..

AUTHOR

Adam Kennedy <adamk@cpan.org>

Thank you to Phase N Australia (http://phase-n.com/) for permitting the open sourcing and release of this distribution as a spin-off from a commercial project.

COPYRIGHT

Copyright 2004 - 2008 Adam Kennedy.

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

The full text of the license can be found in the LICENSE file included with this module.