modules/offline.pl

   1 # Copyright (C) 2011  Alex Schroeder <alex@gnu.org>
   2
   3 # This program is free software: you can redistribute it and/or modify it under
   4 # the terms of the GNU General Public License as published by the Free Software
   5 # Foundation, either version 3 of the License, or (at your option) any later
   6 # version.
   7 #
   8 # This program is distributed in the hope that it will be useful, but WITHOUT
   9 # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  10 # FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
  11 #
  12 # You should have received a copy of the GNU General Public License along with
  13 # this program. If not, see <http://www.gnu.org/licenses/>.
  14
  15 $ModulesDescription .= '<p><a href="http://git.savannah.gnu.org/cgit/oddmuse.git/tree/modules/offline.pl">offline.pl</a>, see <a href="http://www.oddmuse.org/cgi-bin/oddmuse/Plans">Plans</a></p>';
  16
  17 # Based on http://diveintohtml5.org/offline.html
  18
  19 push(@MyAdminCode, \&OfflineMenu);
  20
  21 sub OfflineMenu {
  22   my ($id, $menuref, $restref) = @_;
  23   push(@$menuref,
  24        ScriptLink('action=browse;id=' . UrlEncode($id) . ';offline=1',
  25                   T('Make available offline'),
  26                   'offline'));
  27 }
  28
  29 push(@MyInitVariables, \&InitOffline);
  30
  31 sub InitOffline {
  32   # Make sure we parse path_info and parameters
  33   GetId();
  34   # Switch to HTML5 if the offline parameter is set
  35   if (GetParam('offline', 0)) {
  36     # add link to the manifest listing all the pages
  37     my $manifest = ScriptUrl('action=manifest');
  38     $DocumentHeader = qq{<!DOCTYPE HTML>
  39 <html manifest="$manifest">
  40 };
  41     # HACK ALERT: In order to allow the browser to cache all the pages
  42     # listed in the manifest, we need to disable surge protection for
  43     # the offline pages.
  44     $SurgeProtection = 0;
  45     # every offline page will link to other offline pages
  46     $ScriptName .= '/offline' unless $ScriptName =~ m!/offline$!;
  47     # add some links for Apple devices (boo!)
  48     if ($HtmlHeaders !~ /apple-mobile-web-app-capable/) {
  49       $HtmlHeaders .= qq{
  50 <meta name="apple-mobile-web-app-capable" content="yes" />
  51 <meta name="apple-mobile-web-app-status-bar-style" content="black" />
  52 };
  53     }
  54   }
  55 }
  56
  57 $Action{manifest} = \&DoManifest;
  58
  59 # List all the pages necessary for the offline application.
  60 sub DoManifest {
  61   print GetHttpHeader('text/cache-manifest');
  62   print "CACHE MANIFEST\n";
  63   # make sure to list the URLs for the offline version
  64   local $ScriptName = $ScriptName . '/offline';
  65   # don't forget to URL encode
  66   foreach my $id (AllPagesList()) {
  67     print ScriptUrl(UrlEncode($id)) . "\n";
  68   }
  69   # Missing pages that should show the default text such as
  70   # RecentChanges cannot be added because fetching them results in a
  71   # 404 error.
  72   # foreach my $id (@UserGotoBarPages) {
  73   #   print ScriptUrl($id) . "\n" unless $IndexHash{$id};
  74   # }
  75   # External CSS
  76   print $StyleSheet . "\n" if $StyleSheet;
  77   # FIXME: $StyleSheetPage
  78   # FIXME: external images, stuff in $HtmlHeaders
  79   # Error message all the stuff that's not available offline.
  80   my $offline = ScriptUrl('action=offline');
  81   print qq{
  82 FALLBACK:
  83 / $offline
  84 NETWORK:
  85 *
  86 };
  87 }
  88
  89 $Action{offline} = \&DoOffline;
  90
  91 # Show an excuse for the pages that have not been cached.
  92 sub DoOffline {
  93   ReportError(T('Offline'),
  94               '200 OK',
  95               0, $q->p(T('You are currently offline and what you requested is not part of the offline application. You need to be online to do this.')));
  96 }
  97
  98 # Fix redirection.
  99 *OldOfflineReBrowsePage = *ReBrowsePage;
 100 *ReBrowsePage = *NewOfflineReBrowsePage;
 101
 102 sub NewOfflineReBrowsePage {
 103   my ($id) = @_;
 104   if (GetParam('offline', 0)) {
 105     BrowsePage($id);
 106   } else {
 107     OldOfflineReBrowsePage(@_);
 108   }
 109 }