phpman > perldoc > 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.