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HTML::Link_Miner
return links in a document along with information

HTML::Link_Miner - return links in a document along with information


NAME

HTML::Link_Miner - return links in a document along with information


SYNOPSIS


 require HTML::Link_Miner;

 $p = HTML::Link_Miner->new(\&cb, "http://www.sn.no/";);

 #this is not correct

 sub cb {

     my($tag, %links) = @_;

     print "$tag @{[%links]}\n";

 }

 $p->parse_file("index.html");


DESCRIPTION

This is currently just an idea and is not implemented yet

HTML::Link_Miner is a link extractor. The HTML::Link_Miner 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.

The difference between HTML::LinkExtor and this module is that we try to find all of the useful information we can about each link from the document.

With the HREF from <A> tags we return the text between the start and end tags.

#With the HREF from <IMG> tags we return any ALT text.

With other links, we return the attribute name


INTERFACE

call backs for each link type??

$p = HTML::LinkExtor->new([$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 follwing 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 = "http://www.sn.no/";;  # for instance

  $ua = new LWP::UserAgent;

  # 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 diffent 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

the HTML::Parser manpage, the HTML::Tagset manpage, LWP, URI


COPYRIGHT

Based on LinkExtor and Copyright 1996-2000 Gisle Aas.

Copyright 2001 Michael De La Rue

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

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