HTML::HeadParser(3pm) | User Contributed Perl Documentation | HTML::HeadParser(3pm) |
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.
The ':' character can't be represented in header field names, so if the meta element contains this char it's substituted with '-' before forming the field name.
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.
2023-02-04 | perl v5.36.0 |