IkiWiki/Plugin/graphviz.pm

   1 #!/usr/bin/perl
   2 # graphviz plugin for ikiwiki: render graphviz source as an image.
   3 # Josh Triplett
   4 package IkiWiki::Plugin::graphviz;
   5
   6 use warnings;
   7 use strict;
   8 use IkiWiki;
   9 use IPC::Open2;
  10
  11 sub import { #{{{
  12         hook(type => "preprocess", id => "graph", call => \&graph);
  13 } # }}}
  14
  15 my %graphviz_programs = (
  16         "dot" => 1, "neato" => 1, "fdp" => 1, "twopi" => 1, "circo" => 1
  17 );
  18
  19 sub render_graph (\%) { #{{{
  20         my %params = %{(shift)};
  21
  22         my $src = "$params{type} g {\n";
  23         $src .= "charset=\"utf-8\";\n";
  24         $src .= "ratio=compress;\nsize=\"".($params{width}+0).", ".($params{height}+0)."\";\n"
  25                 if defined $params{width} and defined $params{height};
  26         $src .= $params{src};
  27         $src .= "}\n";
  28
  29         # Use the sha1 of the graphviz code as part of its filename.
  30         eval q{use Digest::SHA1};
  31         error($@) if $@;
  32         my $dest=$params{page}."/graph-".
  33                 IkiWiki::possibly_foolish_untaint(Digest::SHA1::sha1_hex($src)).
  34                 ".png";
  35         will_render($params{page}, $dest);
  36
  37         if (! -e "$config{destdir}/$dest") {
  38                 my $pid;
  39                 my $sigpipe=0;;
  40                 $SIG{PIPE}=sub { $sigpipe=1 };
  41                 $pid=open2(*IN, *OUT, "$params{prog} -Tpng");
  42
  43                 # open2 doesn't respect "use open ':utf8'"
  44                 binmode (IN, ':utf8');
  45                 binmode (OUT, ':utf8');
  46
  47                 print OUT $src;
  48                 close OUT;
  49
  50                 my $png;
  51                 {
  52                         local $/ = undef;
  53                         $png = <IN>;
  54                 }
  55                 close IN;
  56
  57                 waitpid $pid, 0;
  58                 $SIG{PIPE}="DEFAULT";
  59                 return  "[[graph ".gettext("failed to run graphviz")."]]" if ($sigpipe);
  60
  61                 if (! $params{preview}) {
  62                         writefile($dest, $config{destdir}, $png, 1);
  63                 }
  64                 else {
  65                         # can't write the file, so embed it in a data uri
  66                         eval q{use MIME::Base64};
  67                         error($@) if $@;
  68                         return "<img src=\"data:image/png;base64,".
  69                                 encode_base64($png)."\" />";
  70                 }
  71         }
  72
  73         return "<img src=\"".urlto($dest, $params{page})."\" />\n";
  74 } #}}}
  75
  76 sub graph (@) { #{{{
  77         my %params=@_;
  78         $params{src} = "" unless defined $params{src};
  79         $params{type} = "digraph" unless defined $params{type};
  80         $params{prog} = "dot" unless defined $params{prog};
  81         return "[[graph ".gettext("prog not a valid graphviz program")."]]" unless $graphviz_programs{$params{prog}};
  82
  83         return render_graph(%params);
  84 } # }}}
  85
  86 1