NAME

HTML::LinkExtractor - Extract links from an HTML document

DESCRIPTION

HTML::LinkExtractor is used for extracting links from HTML. It is very similar to HTML::LinkExtor, except that besides getting the URL, you also get the link-text.

Example ( please run the examples ):

use HTML::LinkExtractor;
use Data::Dumper;

my $input = q{If <a href="http://perl.com/"> I am a LINK!!! </a>};
my $LX = new HTML::LinkExtractor();

$LX->parse(\$input);

print Dumper($LX->links);
__END__
# the above example will yield
$VAR1 = [
          {
            '_TEXT' => '<a href="http://perl.com/"> I am a LINK!!! </a>',
            'href' => bless(do{\(my $o = 'http://perl.com/')}, 'URI::http'),
            'tag' => 'a'
          }
        ];

HTML::LinkExtractor will also correctly extract nested link-type tags.

SYNOPSIS

## the demo
perl LinkExtractor.pm
perl LinkExtractor.pm file.html othefile.html

## or if the module is installed, but you don't know where

perl -MHTML::LinkExtractor -e" system $^X, $INC{q{HTML/LinkExtractor.pm}} "
perl -MHTML::LinkExtractor -e' system $^X, $INC{q{HTML/LinkExtractor.pm}} '

## or

use HTML::LinkExtractor;
use LWP::Simple qw( get );

my $base = 'http://search.cpan.org';
my $html = get($base.'/recent');
my $LX = new HTML::LinkExtractor();

$LX->parse(\$html);

print qq{<base href="$base">\n};

for my $Link( @{ $LX->links } ) {
## new modules are linked  by /author/NAME/Dist
    if( $$Link{href}=~ m{^\/author\/\w+} ) {
        print $$Link{_TEXT}."\n";
    }
}

undef $LX;
__END__

## or

use HTML::LinkExtractor;
use Data::Dumper;

my $input = q{If <a href="http://perl.com/"> I am a LINK!!! </a>};
my $LX = new HTML::LinkExtractor(
    sub {
        print Data::Dumper::Dumper(@_);
    },
    'http://perlFox.org/',
);

$LX->parse(\$input);
$LX->strip(1);
$LX->parse(\$input);
__END__

#### Calculate to total size of a web-page
#### adds up the sizes of all the images and stylesheets and stuff

use strict;
use LWP::Simple;
use HTML::LinkExtractor;
                                                    #
my $url  = shift || 'http://www.google.com';
my $html = get($url);
my $Total = length $html;
                                                    #
print "initial size $Total\n";
                                                    #
my $LX = new HTML::LinkExtractor(
    sub {
        my( $X, $tag ) = @_;
                                                    #
        unless( grep {$_ eq $tag->{tag} } @HTML::LinkExtractor::TAGS_IN_NEED ) {
                                                    #
print "$$tag{tag}\n";
                                                    #
            for my $urlAttr ( @{$HTML::LinkExtractor::TAGS{$$tag{tag}}} ) {
                if( exists $$tag{$urlAttr} ) {
                    my $size = (head( $$tag{$urlAttr} ))[1];
                    $Total += $size if $size;
print "adding $size\n" if $size;
                }
            }
        }
    },
    $url,
    0
);
                                                    #
$LX->parse(\$html);
                                                    #
print "The total size of \n$url\n is $Total bytes\n";
__END__

METHODS

$LX->new([\&callback, [$baseUrl, [1]]])

Accepts 3 arguments, all of which are optional. If for example you want to pass a $baseUrl, but don't want to have a callback invoked, just put undef in place of a subref.

This is the only class method.

  1. a callback ( a sub reference, as in sub{}, or \&sub) which is to be called each time a new LINK is encountered ( for @HTML::LinkExtractor::TAGS_IN_NEED this means after the closing tag is encountered )

    The callback receives an object reference($LX) and a link hashref.

  2. and a base URL ( URI->new, so its up to you to make sure it's valid which is used to convert all relative URI's to absolute ones.

    $ALinkP{href} = URI->new_abs( $ALink{href}, $base );
  3. A "boolean" (just stick with 1). See the example in "DESCRIPTION". Normally, you'd get back _TEXT that looks like

    '_TEXT' => '<a href="http://perl.com/"> I am a LINK!!! </a>',

    If you turn this option on, you'll get the following instead

    '_TEXT' => ' I am a LINK!!! ',

    The private utility function _stripHTML does this by using HTML::TokeParsers method get_trimmed_text.

    You can turn this feature on an off by using $LX->strip(undef || 0 || 1)

$LX->parse( $filename || *FILEHANDLE || \$FileContent )

Each time you call parse, you should pass it a $filename a *FILEHANDLE or a \$FileContent

Each time you call parse a new HTML::TokeParser::Simple object is created and stored in $this->{_tp}.

You shouldn't need to mess with the TokeParser object.

$LX->links()

Only after you call parse will this method return anything. This method returns a reference to an ArrayOfHashes, which basically looks like (Data::Dumper output)

$VAR1 = [ { type => 'img', src => 'image.png' }, ];

Please note that if yo provide a callback this array will be empty.

$LX->strip( [ 0 || 1 ])

If you pass in undef (or nothing), returns the state of the option. Passing in a true or false value sets the option.

If you wanna know what the option does see $LX->new([\&callback, [$baseUrl, [1]]])

WHAT'S A LINK-type tag

Take a look at %HTML::LinkExtractor::TAGS to see what I consider to be link-type-tag.

Take a look at @HTML::LinkExtractor::VALID_URL_ATTRIBUTES to see all the possible tag attributes which can contain URI's (the links!!)

Take a look at @HTML::LinkExtractor::TAGS_IN_NEED to see the tags for which the '_TEXT' attribute is provided, like <a href="#"> TEST </a>

How can that be?!?!

I took at look at %HTML::Tagset::linkElements and the following URL's

http://www.blooberry.com/indexdot/html/tagindex/all.htm

http://www.blooberry.com/indexdot/html/tagpages/a/a-hyperlink.htm
http://www.blooberry.com/indexdot/html/tagpages/a/applet.htm
http://www.blooberry.com/indexdot/html/tagpages/a/area.htm

http://www.blooberry.com/indexdot/html/tagpages/b/base.htm
http://www.blooberry.com/indexdot/html/tagpages/b/bgsound.htm

http://www.blooberry.com/indexdot/html/tagpages/d/del.htm
http://www.blooberry.com/indexdot/html/tagpages/d/div.htm

http://www.blooberry.com/indexdot/html/tagpages/e/embed.htm
http://www.blooberry.com/indexdot/html/tagpages/f/frame.htm

http://www.blooberry.com/indexdot/html/tagpages/i/ins.htm
http://www.blooberry.com/indexdot/html/tagpages/i/image.htm
http://www.blooberry.com/indexdot/html/tagpages/i/iframe.htm
http://www.blooberry.com/indexdot/html/tagpages/i/ilayer.htm
http://www.blooberry.com/indexdot/html/tagpages/i/inputimage.htm

http://www.blooberry.com/indexdot/html/tagpages/l/layer.htm
http://www.blooberry.com/indexdot/html/tagpages/l/link.htm

http://www.blooberry.com/indexdot/html/tagpages/o/object.htm

http://www.blooberry.com/indexdot/html/tagpages/q/q.htm

http://www.blooberry.com/indexdot/html/tagpages/s/script.htm
http://www.blooberry.com/indexdot/html/tagpages/s/sound.htm

And the special cases 

<!DOCTYPE HTML SYSTEM "http://www.w3.org/DTD/HTML4-strict.dtd">
http://www.blooberry.com/indexdot/html/tagpages/d/doctype.htm
'!doctype'  is really a process instruction, but is still listed
in %TAGS with 'url' as the attribute

and

<meta HTTP-EQUIV="Refresh" CONTENT="5; URL=http://www.foo.com/foo.html">
http://www.blooberry.com/indexdot/html/tagpages/m/meta.htm
If there is a valid url, 'url' is set as the attribute.
The meta tag has no 'attributes' listed in %TAGS.

SEE ALSO

HTML::LinkExtor, HTML::TokeParser::Simple, HTML::Tagset.

AUTHOR

D.H (PodMaster)

Please use http://rt.cpan.org/ to report bugs.

Just go to http://rt.cpan.org/NoAuth/Bugs.html?Dist=HTML-Scrubber to see a bug list and/or repot new ones.

LICENSE

Copyright (c) 2003 by D.H. (PodMaster). All rights reserved.

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. The LICENSE file contains the full text of the license.