IkiWiki/Plugin/toc.pm

   1 #!/usr/bin/perl
   2 # Table Of Contents generator
   3 package IkiWiki::Plugin::toc;
   4
   5 use warnings;
   6 use strict;
   7 use IkiWiki;
   8 use HTML::Parser;
   9
  10 sub import { #{{{
  11         hook(type => "preprocess", id => "toc", call => \&preprocess);
  12         hook(type => "format", id => "toc", call => \&format);
  13 } # }}}
  14
  15 my %tocpages;
  16
  17 sub preprocess (@) { #{{{
  18         my %params=@_;
  19
  20         $params{levels}=1 unless exists $params{levels};
  21
  22         # It's too early to generate the toc here, so just record the
  23         # info.
  24         $tocpages{$params{destpage}}=\%params;
  25
  26         return "\n<div class=\"toc\"></div>\n";
  27 } # }}}
  28
  29 sub format (@) { #{{{
  30         my %params=@_;
  31         my $content=$params{content};
  32
  33         return $content unless exists $tocpages{$params{page}};
  34         %params=%{$tocpages{$params{page}}};
  35
  36         my $p=HTML::Parser->new(api_version => 3);
  37         my $page="";
  38         my $index="";
  39         my %anchors;
  40         my $curlevel;
  41         my $startlevel=0;
  42         my $liststarted=0;
  43         my $indent=sub { "\t" x $curlevel };
  44         $p->handler(start => sub {
  45                 my $tagname=shift;
  46                 my $text=shift;
  47                 if ($tagname =~ /^h(\d+)$/i) {
  48                         my $level=$1;
  49                         my $anchor="index".++$anchors{$level}."h$level";
  50                         $page.="$text<a name=\"$anchor\" />";
  51
  52                         # Take the first header level seen as the topmost level,
  53                         # even if there are higher levels seen later on.
  54                         if (! $startlevel) {
  55                                 $startlevel=$level;
  56                                 $curlevel=$startlevel-1;
  57                         }
  58                         elsif ($level < $startlevel) {
  59                                 $level=$startlevel;
  60                         }
  61
  62                         return if $level - $startlevel >= $params{levels};
  63
  64                         if ($level > $curlevel) {
  65                                 while ($level > $curlevel + 1) {
  66                                         $index.=&$indent."<ol>\n";
  67                                         $curlevel++;
  68                                         $index.=&$indent."<li class=\"L$curlevel\">\n";
  69                                 }
  70                                 $index.=&$indent."<ol>\n";
  71                                 $curlevel=$level;
  72                                 $liststarted=1;
  73                         }
  74                         elsif ($level < $curlevel) {
  75                                 while ($level < $curlevel) {
  76                                         $index.=&$indent."</li>\n" if $curlevel;
  77                                         $curlevel--;
  78                                         $index.=&$indent."</ol>\n";
  79                                 }
  80                                 $liststarted=0;
  81                         }
  82
  83                         $p->handler(text => sub {
  84                                 $page.=join("", @_);
  85                                 $index.=&$indent."</li>\n" unless $liststarted;
  86                                 $liststarted=0;
  87                                 $index.=&$indent."<li class=\"L$curlevel\">".
  88                                         "<a href=\"#$anchor\">".
  89                                         join("", @_).
  90                                         "</a>\n";
  91                                 $p->handler(text => undef);
  92                         }, "dtext");
  93                 }
  94                 else {
  95                         $page.=$text;
  96                 }
  97         }, "tagname, text");
  98         $p->handler(default => sub { $page.=join("", @_) }, "text");
  99         $p->parse($content);
 100         $p->eof;
 101
 102         while ($startlevel && $curlevel >= $startlevel) {
 103                 $index.=&$indent."</li>\n" if $curlevel;
 104                 $curlevel--;
 105                 $index.=&$indent."</ol>\n";
 106         }
 107
 108         $page=~s/(<div class=\"toc\">)/$1\n$index/;
 109         return $page;
 110 }
 111
 112 1