Files
kensanata.oddmuse/modules/image.pl
Alex Schroeder 5da9ce64c0 Lazy loading of images
Use the new loading="lazy" attribute for images.
2020-08-12 20:53:58 +02:00

136 lines
4.9 KiB
Perl

# Copyright (C) 2004, 2005, 2006, 2007 Alex Schroeder <alex@emacswiki.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
use strict;
use v5.10;
AddModuleDescription('image.pl', 'Image Extension');
our ($q, @MyRules, $FullUrlPattern, $FreeLinkPattern, $FreeInterLinkPattern, %IndexHash, $ScriptName, $UsePathInfo, $Monolithic);
our ($ImageUrlPath);
$ImageUrlPath = '/images'; # URL where the images are to be found
push(@MyRules, \&ImageSupportRule);
# [[image/class:page name|alt text|target]]
sub ImageSupportRule {
my $result = undef;
if (m!\G\[\[image((/[-a-z]+)*)( external)?:\s*([^]|]+?)\s*(\|[^]|]+?)?\s*(\|[^]|]*?)?\s*(\|[^]|]*?)?\s*(\|[^]|]*?)?\s*\]\](\{([^}]+)\})?!cg) {
my $oldpos = pos;
my $class = 'image' . $1;
my $external = $3;
my $name = $4;
# Don't generate an alt text if none was specified, since the rule
# forces you to pick an alt text if you're going to provide a
# link target.
my $alt = UnquoteHtml($5 ? substr($5, 1) : '');
$alt = NormalToFree($name)
if not $alt and not $external and $name !~ /^$FullUrlPattern$/;
my $link = $6 ? substr($6, 1) : '';
my $caption = $7 ? substr($7, 1) : '';
my $reference = $8 ? substr($8, 1) : '';
my $comments = $10;
my $id = FreeToNormal($name);
$class =~ s!/! !g;
my $linkclass = $class;
my $found = 1;
# link to the image if no link was given
$link = $name unless $link;
if ($link =~ /^($FullUrlPattern|$FreeInterLinkPattern)$/
or $link =~ /^$FreeLinkPattern$/ and not $external) {
($link, $linkclass) = ImageGetExternalUrl($link, $linkclass);
} else {
$link = $ImageUrlPath . '/' . ImageUrlEncode($link);
}
my $src = $name;
if ($src =~ /^($FullUrlPattern|$FreeInterLinkPattern)$/) {
($src) = ImageGetExternalUrl($src);
} elsif ($src =~ /^$FreeLinkPattern$/ and not $external) {
$found = $IndexHash{FreeToNormal($src)};
$src = ImageGetInternalUrl($src) if $found;
} else {
$src = $ImageUrlPath . '/' . ImageUrlEncode($name);
}
if ($found) {
$result = $q->img({-src=>$src, -alt=>$alt, -title=>$alt, -class=>'upload', -loading=>'lazy'});
$result = $q->a({-href=>$link, -class=>$linkclass}, $result);
if ($comments) {
for (split '\n', $comments) {
my $valRegex = qr/(([0-9.]+[a-z]*%?)\s+)/;
if ($_ =~ /^\s*(([a-zA-Z ]+)\/)?$valRegex$valRegex$valRegex$valRegex(.*)$/) { # can't use {4} here? :(
my $commentClass = $2 ? "imagecomment $2" : 'imagecomment';
$result .= $q->div({-class=>$commentClass, -style=>"position: absolute; top: $6; left: $4; width: $8; height: $10"}, $11);
}
}
$result = CloseHtmlEnvironments() . $q->div({-class=>"imageholder", -style=>"position: relative"}, $result);
}
} else {
$result = GetDownloadLink($src, 1, undef, $alt);
}
if ($caption) {
if ($reference) {
my $refclass = $class;
($reference, $refclass) = ImageGetExternalUrl($reference, $refclass);
$caption = $q->a({-href=>$reference, -class=>$refclass}, $caption);
}
$result .= $q->br() . $q->span({-class=>'caption'}, $caption);
$result = CloseHtmlEnvironments() . $q->div({-class=>$class}, $result);
}
pos = $oldpos;
}
return $result;
}
sub ImageUrlEncode {
# url encode everything except for slashes
return join('/', map { UrlEncode($_) } split(/\//, shift));
}
sub ImageGetExternalUrl {
my ($link, $class) = @_;
if ($link =~ /^$FullUrlPattern$/) {
$link = UnquoteHtml($link);
$class .= ' outside';
} elsif ($link =~ /^$FreeInterLinkPattern$/) {
my ($site, $page) = split(/:/, $link, 2);
$link = GetInterSiteUrl($site, $page, 1); # quote!
$class .= ' inter ' . $site;
} else {
$link = FreeToNormal($link);
if (substr($link, 0, 1) eq '/') {
# do nothing -- relative URL on the same server
} elsif ($UsePathInfo and !$Monolithic) {
$link = $ScriptName . '/' . $link;
} elsif ($Monolithic) {
# if used together with all.pl
$link = '#' . $link;
} else {
$link = $ScriptName . '?' . $link;
}
}
return ($link, $class);
}
# split off to support overriding from Static Extension
sub ImageGetInternalUrl {
my $id = FreeToNormal(shift);
if ($UsePathInfo) {
return $ScriptName . "/download/" . UrlEncode($id);
}
return $ScriptName . "?action=download;id=" . UrlEncode($id);
}