NAME¶
HTML::Strip - Perl extension for stripping HTML markup from text.
SYNOPSIS¶
use HTML::Strip;
my $hs = HTML::Strip->new();
my $clean_text = $hs->parse( $raw_html );
$hs->eof;
DESCRIPTION¶
This module simply strips HTML-like markup from text in a very quick and brutal
manner. It could quite easily be used to strip XML or SGML from text as well;
but removing HTML markup is a much more common problem, hence this module
lives in the HTML:: namespace.
It is written in XS, and thus about five times quicker than using regular
expressions for the same task.
It does
not do any syntax checking (if you want that, use HTML::Parser),
instead it merely applies the following rules:
- 1.
- Anything that looks like a tag, or group of tags will be
replaced with a single space character. Tags are considered to be anything
that starts with a "<" and ends with a ">"; with
the caveat that a ">" character may appear in either of the
following without ending the tag:
- Quote
- Quotes are considered to start with either a "'"
or a """ character, and end with a matching character
not preceded by an even number or escaping slashes (i.e.
"\"" does not end the quote but "\\\\""
does).
- Comment
- If the tag starts with an exclamation mark, it is assumed
to be a declaration or a comment. Within such tags, ">"
characters do not end the tag if they appear within pairs of double dashes
(e.g. "<!-- <a href="old.htm">old page</a>
-->" would be stripped completely).
- 2.
- Anything the appears within so-called strip tags is
stripped as well. By default, these tags are "title",
"script", "style" and "applet".
HTML::Strip maintains state between calls, so you can parse a document in chunks
should you wish. If one chunk ends half-way through a tag, quote, comment, or
whatever; it will remember this, and expect the next call to parse to start
with the remains of said tag.
If this is not going to be the case, be sure to call $hs->
eof()
between calls to $hs->
parse().
METHODS¶
- new()
- Constructor. Can optionally take a hash of settings (with
keys corresponsing to the "set_" methods below).
For example, the following is a valid constructor:
my $hs = HTML::Strip->new(
striptags => [ 'script', 'iframe' ],
emit_spaces => 0
);
- parse()
- Takes a string as an argument, returns it stripped of
HTML.
- eof()
- Resets the current state information, ready to parse a new
block of HTML.
- clear_striptags()
- Clears the current set of strip tags.
- add_striptag()
- Adds the string passed as an argument to the current set of
strip tags.
- set_striptags()
- Takes a reference to an array of strings, which replace the
current set of strip tags.
- set_emit_spaces()
- Takes a boolean value. If set to false, HTML::Strip will
not attempt any conversion of tags into spaces. Set to true by
default.
- set_decode_entities()
- Takes a boolean value. If set to false, HTML::Strip will
decode HTML entities. Set to true by default.
LIMITATIONS¶
- Whitespace
- Despite only outputting one space character per group of
tags, and avoiding doing so when tags are bordered by spaces or the start
or end of strings, HTML::Strip can often output more than desired; such as
with the following HTML:
<h1> HTML::Strip </h1> <p> <em> <strong> fast, and brutal </strong> </em> </p>
Which gives the following output:
" HTML::Strip fast, and
brutal "
Thus, you may want to post-filter the output of HTML::Strip to remove excess
whitespace (for example, using "tr/ / /s;"). (This has been
improved since previous releases, but is still an issue)
- HTML Entities
- HTML::Strip will only attempt decoding of HTML entities if
HTML::Entities is installed.
EXPORT¶
None by default.
AUTHOR¶
Alex Bowley <kilinrax@cpan.org>
SEE ALSO¶
perl, HTML::Parser, HTML::Entities