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   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 3.00;
   9 use IPC::Open2;
  10
  11 sub import {
  12         hook(type => "getsetup", id => "graphviz", call => \&getsetup);
  13         hook(type => "preprocess", id => "graph", call => \&graph);
  14 }
  15
  16 sub getsetup () {
  17         return
  18                 plugin => {
  19                         safe => 1,
  20                         rebuild => undef,
  21                 },
  22 }
  23
  24 my %graphviz_programs = (
  25         "dot" => 1, "neato" => 1, "fdp" => 1, "twopi" => 1, "circo" => 1
  26 );
  27
  28 sub render_graph (\%) {
  29         my %params = %{(shift)};
  30
  31         my $src = "$params{type} g {\n";
  32         $src .= "charset=\"utf-8\";\n";
  33         $src .= "ratio=compress;\nsize=\"".($params{width}+0).", ".($params{height}+0)."\";\n"
  34                 if defined $params{width} and defined $params{height};
  35         $src .= $params{src};
  36         $src .= "}\n";
  37
  38         # Use the sha1 of the graphviz code as part of its filename.
  39         eval q{use Digest::SHA1};
  40         error($@) if $@;
  41         my $dest=$params{page}."/graph-".
  42                 IkiWiki::possibly_foolish_untaint(Digest::SHA1::sha1_hex($src)).
  43                 ".png";
  44         will_render($params{page}, $dest);
  45
  46         if (! -e "$config{destdir}/$dest") {
  47                 my $pid;
  48                 my $sigpipe=0;;
  49                 $SIG{PIPE}=sub { $sigpipe=1 };
  50                 $pid=open2(*IN, *OUT, "$params{prog} -Tpng");
  51
  52                 # open2 doesn't respect "use open ':utf8'"
  53                 binmode (OUT, ':utf8');
  54
  55                 print OUT $src;
  56                 close OUT;
  57
  58                 my $png;
  59                 {
  60                         local $/ = undef;
  61                         $png = <IN>;
  62                 }
  63                 close IN;
  64
  65                 waitpid $pid, 0;
  66                 $SIG{PIPE}="DEFAULT";
  67                 error gettext("failed to run graphviz") if $sigpipe;
  68
  69                 if (! $params{preview}) {
  70                         writefile($dest, $config{destdir}, $png, 1);
  71                 }
  72                 else {
  73                         # can't write the file, so embed it in a data uri
  74                         eval q{use MIME::Base64};
  75                         error($@) if $@;
  76                         return "<img src=\"data:image/png;base64,".
  77                                 encode_base64($png)."\" />";
  78                 }
  79         }
  80
  81         if ($params{preview}) {
  82                 return "<img src=\"".urlto($dest, "")."\" />\n";
  83         }
  84         else {
  85                 return "<img src=\"".urlto($dest, $params{destpage})."\" />\n";
  86         }
  87 }
  88
  89 sub graph (@) {
  90         my %params=@_;
  91         $params{src} = "" unless defined $params{src};
  92         $params{type} = "digraph" unless defined $params{type};
  93         $params{prog} = "dot" unless defined $params{prog};
  94         error gettext("prog not a valid graphviz program") unless $graphviz_programs{$params{prog}};
  95
  96         return render_graph(%params);
  97 }
  98
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