A single-threaded crawler/spider for the web.
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MANIFEST
META.yml
Makefile.PL
README.markdown

README.markdown

NAME

WWW::Crawler::Lite - A single-threaded crawler/spider for the web.

SYNOPSIS

my %pages = ( );
my $pattern = 'https?://example\.com\/';
my %links = ( );
my $downloaded = 0;

my $crawler;
$crawler = WWW::Crawler::Lite->new(
  agent       => 'MySuperBot/1.0',
  url_pattern => $pattern,
  http_accept => [qw( text/plain text/html application/xhtml+xml )],
  link_parser => 'default',
  on_response => sub {
    my ($url, $res) = @_;

  warn "$url contains " . $res->content;
  $downloaded++;
  $crawler->stop() if $downloaded++ > 5;
},
follow_ok   => sub {
  my ($url) = @_;
  # If you like this url and want to use it, then return a true value:
  return 1;
},
on_link     => sub {
  my ($from, $to, $text) = @_;

  return if exists($pages{$to}) && $pages{$to} eq 'BAD';
  $pages{$to}++;
  $links{$to} ||= [ ];
  push @{$links{$to}}, { from => $from, text => $text };
},
on_bad_url => sub {
  my ($url) = @_;

    # Mark this url as 'bad':
    $pages{$url} = 'BAD';
  }
);
$crawler->crawl( url => "http://example.com/" );

warn "DONE!!!!!";

use Data::Dumper;
map {
  warn "$_ ($pages{$_} incoming links) -> " . Dumper($links{$_})
} sort keys %links;

DESCRIPTION

WWW::Crawler::Lite is a single-threaded spider/crawler for the web. It can be used within a mod_perl, CGI or Catalyst-style environment because it does not fork or use threads.

The callback-based interface is fast and simple, allowing you to focus on simply processing the data that WWW::Crawler::Lite extracts from the target website.

PUBLIC METHODS

new( %args )

Creates and returns a new WWW::Crawler::Lite object.

The %args hash is not required, but may contain the following elements:

  • agent - String

Used as the user-agent string for HTTP requests.

Default Value: - WWW-Crawler-Lite/$VERSION $^O

  • url_pattern - RegExp or String

New links that do not match this pattern will not be added to the processing queue.

Default Value: https?://.+

  • http_accept - ArrayRef

This can be used to filter out unwanted responses.

  • link_parser - String

Valid values: 'default' and 'HTML::LinkExtor'

The default value is 'default' which uses a naive regexp to do the link parsing.

The upshot of using 'default' is that the regexp will also find the hyperlinked text or alt-text (of a hyperlinked img tag) and give that to your 'on_link' handler.

Default Value: [qw( text/html text/plain application/xhtml+xml )]

  • on_response($url, $response) - CodeRef

Called whenever a successful response is returned.

  • on_link($from, $to, $text) - CodeRef

Called whenever a new link is found. Arguments are:

- $from

The URL that is linked *from*

- $to

The URL that is linked *to*

- $text

The anchor text (eg: The HTML within the link - <a href="...">__This Text Here__</a>)
  • on_bad_url($url) - CodeRef

Called whenever an unsuccessful response is received.

  • delay_seconds - Number

Indicates the length of time (in seconds) that the crawler should pause before making each request. This can be useful when you want to spider a website, not launch a denial of service attack on it.

stop( )

Causes the crawler to stop processing its queue of URLs.

AUTHOR

John Drago jdrago_999@yahoo.com

COPYRIGHT

This software is Free software and may be used and redistributed under the same terms as perl itself.