HTML::TagFilter does this admirably. It's a subclass of HTML::Parser and allows you to specify what tags/attributes to allow/deny similarly to what you're doing. You'd probably need to tweak this a little to fit into your code the way you want, but it should do the trick.

use HTML::TagFilter;
my $tf = HTML::TagFilter->new(
                  allow=>{
                  p=>{'any'},
                  i=>{'any'},                  
                  b=>{'any'},
                  code=>{'any'},
                  br=>{'any'},
                  u=>{'any'},
                  pre=>{'any'},
                  img=>{width=>['any'],
                    height=>['any'],
                    border=>['any'],
                    src=>['any'],
                    },
                  a=>{href=>['any'],
                      target=>['any'],
                      name=>['any'],
                  },
                  
                  }, 
                  deny=>{}, 
                  log_rejects => 1, 
                  strip_comments => 1, 
                  );

sub filter_html{
    $tf->filter(shift);
}

[download]

Update: This module will freak out if you try to install/use it on anything earlier than perl 5.6, I believe because it uses Warnings. As another monk pointed out (forgot who, it was a while ago), you can just comment this out (or install it, I suppose) and it'll work fine.

-Any sufficiently advanced technology is
indistinguishable from doubletalk.

In reply to Re: Safe HTML output? by Hero Zzyzzx
in thread Safe HTML output? by gav^

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.