HTML::TagParser(3)

NAME
HTML::TagParser - Yet another HTML document parser with DOM-like methods

SYNOPSIS
Parse a HTML file and find its <title> element's value.

    my $html = HTML::TagParser->new( "index-j.html" );
    my $elem = $html->getElementsByTagName( "title" );
    print "<title>", $elem->innerText(), "</title>\n" if ref $elem;

Parse a HTML source and find its first <form action=""> attribute's value and find all input elements belonging to this form.

    my $src  = '<html><form action="hoge.cgi">...</form></html>';
    my $html = HTML::TagParser->new( $src );
    my $elem = $html->getElementsByTagName( "form" );
    print "<form action=\"", $elem->getAttribute("action"), "\">\n" if ref $elem;
    my @first_inputs = $elem->subTree()->getElementsByTagName( "input" );
    my $form = $first_inputs[0]->getParent();

Fetch a HTML file via HTTP, and display its all <a> elements and attributes.

    my $url  = 'http://www.kawa.net/xp/index-e.html';
    my $html = HTML::TagParser->new( $url );
    my @list = $html->getElementsByTagName( "a" );
    foreach my $elem ( @list ) {
        my $tagname = $elem->tagName;
        my $attr = $elem->attributes;
        my $text = $elem->innerText;
        print "<$tagname";
        foreach my $key ( sort keys %$attr ) {
            print " $key=\"$attr->{$key}\"";
        }
        if ( $text eq "" ) {
            print " />\n";
        } else {
            print ">$text</$tagname>\n";
        }
    }

DESCRIPTION
HTML::TagParser is a pure Perl module which parses HTML/XHTML files. This module provides some methods like DOM interface. This module is not strict about XHTML format because many of HTML pages are not strict. You know, many pages use <br> elemtents instead of <br/> and have <p> elements which are not closed.

METHODS

  $html = HTML::TagParser->new();
This method constructs an empty instance of the "HTML::TagParser" class.

  $html = HTML::TagParser->new( $url );
If new() is called with a URL, this method fetches a HTML file from remote web server and parses it and returns its instance. URI::Fetch module is required to fetch a file.

  $html = HTML::TagParser->new( $file );
If new() is called with a filename, this method parses a local HTML file and returns its instance

  $html = HTML::TagParser->new( "<html>...snip...</html>" );
If new() is called with a string of HTML source code, this method parses it and returns its instance.

  $html->fetch( $url, %param );
This method fetches a HTML file from remote web server and parse it. The second argument is optional parameters for URI::Fetch module.

  $html->open( $file );
This method parses a local HTML file.

  $html->parse( $source );
This method parses a string of HTML source code.

  $elem = $html->getElementById( $id );
This method returns the element which id attribute is $id.

  @elem = $html->getElementsByName( $name );
This method returns an array of elements which name attribute is $name. On scalar context, the first element is only retruned.

  @elem = $html->getElementsByTagName( $tagname );
This method returns an array of elements which tagName is $tagName. On scalar context, the first element is only retruned.

  @elem = $html->getElementsByClassName( $class );
This method returns an array of elements which className is $tagName. On scalar context, the first element is only retruned.

  @elem = $html->getElementsByAttribute( $attrname, $value );
This method returns an array of elements which $attrname attribute's value is $value. On scalar context, the first element is only retruned.

HTML::TagParser::Element SUBCLASS

  $tagname = $elem->tagName();
This method returns $elem's tagName.

  $text = $elem->id();
This method returns $elem's id attribute.

  $text = $elem->innerText();
This method returns $elem's innerText without tags.

  $subhtml = $elem->subTree();
This method returns a new object of class HTML::Parser, with all the elements that are in the DOM hierarchy under $elem.

  $elem = $elem->nextSibling();
This method returns the next sibling within the same parent. It returns undef when called on a closing tag or on the lastChild node of a parentNode.

  $elem = $elem->previousSibling();
This method returns the previous sibling within the same parent. It returns undef when called on the firstChild node of a parentNode.

  $child_elem = $elem->firstChild();
This method returns the first child node of $elem. It returns undef when called on a closing tag element or on a non-container or empty container element.

  $child_elems = $elem->childNodes();
This method creates an array of all child nodes of $elem and returns the array by reference. It returns an empty array-ref [] whenever firstChild() would return undef.

  $child_elem = $elem->lastChild();
This method returns the last child node of $elem. It returns undef whenever firstChild() would return undef.

  $parent = $elem->parentNode();
This method returns the parent node of $elem. It returns undef when called on root nodes.

  $attr = $elem->attributes();
This method returns a hash of $elem's all attributes.

  $value = $elem->getAttribute( $key );
This method returns the value of $elem's attributes which name is $key.

BUGS
The HTML-Parser is simple. Methods innerText and subTree may be fooled by nested tags or embedded javascript code.

The methods with 'Sibling', 'child' or 'Child' in their names do not cache their results. The most expensive ones are lastChild() and previousSibling(). parentNode() is also expensive, but only once. It does caching.

The DOM tree is read-only, as this is just a parser.

INTERNATIONALIZATION
This module natively understands the character encoding used in document by parsing its meta element.

    <meta http-equiv="Content-Type" content="text/html; charset=Shift_JIS">

The parsed document's encoding is converted as this class's fixed internal encoding "UTF-8".

AUTHORS AND CONTRIBUTORS
    drry [drry]
    Juergen Weigert [jnw]
    Yusuke Kawasaki [kawasaki] [kawanet]
    Tim Wilde [twilde]

COPYRIGHT AND LICENSE
The following copyright notice applies to all the files provided in this distribution, including binary files, unless explicitly noted otherwise.

Copyright 2006-2012 Yusuke Kawasaki

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