| HTML::LinkExtor(3pm) - phpMan
HTML::LinkExtor(3pm) User Contributed Perl Documentation HTML::LinkExtor(3pm)
NAME
HTML::LinkExtor - Extract links from an HTML document
SYNOPSIS
require HTML::LinkExtor;
$p = HTML::LinkExtor->new(\&cb, "http://www.perl.org/");
sub cb {
my($tag, %links) = @_;
print "$tag @{[%links]}\n";
}
$p->parse_file("index.html");
DESCRIPTION
HTML::LinkExtor is an HTML parser that extracts links from an HTML document. The
HTML::LinkExtor is a subclass of HTML::Parser. This means that the document should be
given to the parser by calling the $p->parse() or $p->parse_file() methods.
$p = HTML::LinkExtor->new
$p = HTML::LinkExtor->new( $callback )
$p = HTML::LinkExtor->new( $callback, $base )
The constructor takes two optional arguments. The first is a reference to a callback
routine. It will be called as links are found. If a callback is not provided, then
links are just accumulated internally and can be retrieved by calling the $p->links()
method.
The $base argument is an optional base URL used to absolutize all URLs found. You
need to have the URI module installed if you provide $base.
The callback is called with the lowercase tag name as first argument, and then all
link attributes as separate key/value pairs. All non-link attributes are removed.
$p->links
Returns a list of all links found in the document. The returned values will be
anonymous arrays with the following elements:
[$tag, $attr => $url1, $attr2 => $url2,...]
The $p->links method will also truncate the internal link list. This means that if
the method is called twice without any parsing between them the second call will
return an empty list.
Also note that $p->links will always be empty if a callback routine was provided when
the HTML::LinkExtor was created.
EXAMPLE
This is an example showing how you can extract links from a document received using LWP:
use LWP::UserAgent;
use HTML::LinkExtor;
use URI::URL;
$url = "http://www.perl.org/"; # for instance
$ua = LWP::UserAgent->new;
# Set up a callback that collect image links
my @imgs = ();
sub callback {
my($tag, %attr) = @_;
return if $tag ne 'img'; # we only look closer at <img ...>
push(@imgs, values %attr);
}
# Make the parser. Unfortunately, we don't know the base yet
# (it might be different from $url)
$p = HTML::LinkExtor->new(\&callback);
# Request document and parse it as it arrives
$res = $ua->request(HTTP::Request->new(GET => $url),
sub {$p->parse($_[0])});
# Expand all image URLs to absolute ones
my $base = $res->base;
@imgs = map { $_ = url($_, $base)->abs; } @imgs;
# Print them out
print join("\n", @imgs), "\n";
SEE ALSO
HTML::Parser, HTML::Tagset, LWP, URI::URL
COPYRIGHT
Copyright 1996-2001 Gisle Aas.
This library is free software; you can redistribute it and/or modify it under the same
terms as Perl itself.
perl v5.20.1 2013-03-25 HTML::LinkExtor(3pm)
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