NAME

Class::DBI::Pager - Pager utility for Class::DBI

SYNOPSIS

  package CD;
  use base qw(Class::DBI);
  __PACKAGE__->set_db(...);

  use Class::DBI::Pager;        # just use it

  # then, in client code!
  package main;

  use CD;
  my $pager = CD->pager(20, 1);     # ($items_per_page, $current_page)
  my @disks = $pager->retrieve_all;

DESCRIPTION

Class::DBI::Pager is a plugin for Class::DBI, which glues Data::Page with Class::DBI. This module reduces your work a lot, for example when you have to do something like:

  * retrieve objects from a database
  * display objects with 20 items per page

In addition, your work will be reduced more, when you use Template-Toolkit as your templating engine. See "EXAMPLE" for details.

EXAMPLE

  # Controller: (MVC's C)
  my $query    = CGI->new;
  my $template = Template->new;

  my $pager    = Film->pager(20, $query->param('page') || 1);
  my $movies   = $pager->retrieve_all;
  $template->process($input, {
      movies => $movies,
      pager  => $pager,
  });

  # View: (MVC's V)
  Matched [% pager.total_entries %] items.

  [% WHILE (movie = movies.next) %]
  Title: [% movie.title | html %]
  [% END %]

  ### navigation like: [1] [2] [3]
  [% FOREACH num = [pager.first_page .. pager.last_page] %]
  [% IF num == pager.current_page %][[% num %]]
  [% ELSE %]<a href="display?page=[% num %]">[[% num %]]</a>[% END %]
  [% END %]

  ### navigation like: prev 20 | next 20
  [% IF pager.previous_page %]
  <a href="display?page=[% pager.previous_page %]">
  prev [% pager.entries_per_page %]</a> |
  [% END %]
  [% IF pager.next_page %]
  <a href="display?page=[% pager.next_page %]">
  next [% pager.entries_per_page %]</a>
  [% END %]

NOTE / TODO

This modules internally retrieves itertors, then creates "Data::Page" object for paging utility. Using SQL clauses "LIMIT" and/or "OFFSET" with "DBIx::Pager" might be more memory efficient.

AUTHOR

Tatsuhiko Miyagawa <miyagawa@bulknews.net>

Original idea by Tomohiro Ikebe <ikebe@cpan.org>