NAME¶
HTML::HeadParser - Parse <HEAD> section of a HTML document
SYNOPSIS¶
require HTML::HeadParser;
$p = HTML::HeadParser->new;
$p->parse($text) and print "not finished";
$p->header('Title') # to access <title>....</title>
$p->header('Content-Base') # to access <base href="http://...">
$p->header('Foo') # to access <meta http-equiv="Foo" content="...">
$p->header('X-Meta-Author') # to access <meta name="author" content="...">
$p->header('X-Meta-Charset') # to access <meta charset="...">
DESCRIPTION¶
The "HTML::HeadParser" is a specialized (and lightweight)
"HTML::Parser" that will only parse the <HEAD>...</HEAD>
section of an HTML document. The
parse() method will return a FALSE
value as soon as some <BODY> element or body text are found, and should
not be called again after this.
Note that the "HTML::HeadParser" might get confused if raw undecoded
UTF-8 is passed to the
parse() method. Make sure the strings are
properly decoded before passing them on.
The "HTML::HeadParser" keeps a reference to a header object, and the
parser will update this header object as the various elements of the
<HEAD> section of the HTML document are recognized. The following header
fields are affected:
- Content-Base:
- The Content-Base header is initialized from the
<base href="..."> element.
- Title:
- The Title header is initialized from the
<title>...</title> element.
- Isindex:
- The Isindex header will be added if there is a
<isindex> element in the <head>. The header value is
initialized from the prompt attribute if it is present. If no
prompt attribute is given it will have '?' as the value.
- X-Meta-Foo:
- All <meta> elements containing a "name"
attribute will result in headers using the prefix "X-Meta-"
appended with the value of the "name" attribute as the name of
the header, and the value of the "content" attribute as the
pushed header value.
<meta> elements containing a "http-equiv" attribute will
result in headers as in above, but without the "X-Meta-" prefix
in the header name.
<meta> elements containing a "charset" attribute will result
in an "X-Meta-Charset" header, using the value of the
"charset" attribute as the pushed header value.
METHODS¶
The following methods (in addition to those provided by the superclass) are
available:
- $hp = HTML::HeadParser->new
- $hp = HTML::HeadParser->new( $header )
- The object constructor. The optional $header argument
should be a reference to an object that implement the header() and
push_header() methods as defined by the "HTTP::Headers"
class. Normally it will be of some class that is a or delegates to the
"HTTP::Headers" class.
If no $header is given "HTML::HeadParser" will create an
"HTTP::Headers" object by itself (initially empty).
- $hp->header;
- Returns a reference to the header object.
- $hp->header( $key )
- Returns a header value. It is just a shorter way to write
"$hp->header->header($key)".
EXAMPLE¶
$h = HTTP::Headers->new;
$p = HTML::HeadParser->new($h);
$p->parse(<<EOT);
<title>Stupid example</title>
<base href="http://www.linpro.no/lwp/">
Normal text starts here.
EOT
undef $p;
print $h->title; # should print "Stupid example"
SEE ALSO¶
HTML::Parser, HTTP::Headers
The "HTTP::Headers" class is distributed as part of the
libwww-perl package. If you don't have that distribution installed you
need to provide the $header argument to the "HTML::HeadParser"
constructor with your own object that implements the documented protocol.
COPYRIGHT¶
Copyright 1996-2001 Gisle Aas. All rights reserved.
This library is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.