+#!/usr/bin/perl
+package IkiWiki::Plugin::embed;
+
+use warnings;
+use strict;
+use IkiWiki 2.00;
+
+my $attribr=qr/[^<>"]+/;
+
+# regexp matching known-safe html
+my $safehtml=qr{(
+ # google maps
+ <\s*iframe\s+width="\d+"\s+height="\d+"\s+frameborder="$attribr"\s+
+ scrolling="$attribr"\s+marginheight="\d+"\s+marginwidth="\d+"\s+
+ src="http://maps.google.com/\?$attribr"\s*>\s*</iframe>
+
+ |
+
+ # youtube
+ <\s*object\s+width="\d+"\s+height="\d+"\s*>\s*
+ <\s*param\s+name="movie"\s+value="http://www.youtube.com/v/$attribr"\s*>\s*
+ </param>\s*
+ <\s*param\s+name="wmode"\s+value="transparent"\s*>\s*</param>\s*
+ <embed\s+src="http://www.youtube.com/v/$attribr"\s+
+ type="application/x-shockwave-flash"\s+wmode="transparent"\s+
+ width="\d+"\s+height="\d+"\s*>\s*</embed>\s*</object>
+
+ |
+
+ # google video
+ <\s*embed\s+style="\s*width:\d+px;\s+height:\d+px;\s*"\s+id="$attribr"\s+
+ type="application/x-shockwave-flash"\s+
+ src="http://video.google.com/googleplayer.swf\?$attribr"\s+
+ flashvars=""\s*>\s*</embed>
+
+ |
+
+ # google calendar
+ <\s*iframe\s+src="http://www.google.com/calendar/embed\?src=$attribr"\s+
+ style="\s*border-width:\d+\s*"\s+width="\d+"\s+frameborder="\d+"\s*
+ height="\d+"\s*>\s*</iframe>
+)}sx;
+
+my @embedded;
+
+sub import { #{{{
+ hook(type => "filter", id => "embed", call => \&filter);
+} # }}}
+
+sub embed ($) { #{{{
+ hook(type => "format", id => "embed", call => \&format) unless @embedded;
+ push @embedded, shift;
+ return "<div class=\"embed$#embedded\"></div>";
+} #}}}
+
+sub filter (@) { #{{{
+ my %params=@_;
+ $params{content} =~ s/$safehtml/embed($1)/eg;
+ return $params{content};
+} # }}}
+
+sub format (@) { #{{{
+ my %params=@_;
+ $params{content} =~ s/<div class="embed(\d+)"><\/div>/$embedded[$1]/eg;
+ return $params{content};
+} # }}}
+
+1