doc/plugins/contrib/asymptote.mdwn

   1 [[!template id=plugin name=asymptote author="[Peter Simons](http://cryp.to/)"]]
   2 [[!tag type/widget]]
   3
   4 This plugin provides the [[ikiwiki/directive/asymptote]]
   5 [[ikiwiki/directive]] which allows embedding
   6 [asymptote](http://asymptote.sourceforge.net/) diagrams in a page.
   7
   8 Security implications: asymptote has functions for reading files and
   9 other dangerous stuff, so enabling this plugin means that everyone who
  10 can edit your Wiki can also read any file from your hard drive thats
  11 accessible to the user running Ikiwiki.
  12
  13 [[!if test="enabled(asymptote)" then="""
  14 An example diagram:
  15
  16 [[!asymptote src="""
  17 import geometry;
  18 unitsize(1cm);
  19 triangle t = triangle((0,0), (4,0), (0.5,2));
  20 show(La="$D$", Lb="$E$", Lc="", t);
  21 dot(t.A^^t.B^^t.C);
  22 point pD = midpoint(t.BC); dot(pD);
  23 point pE = midpoint(t.AC); dot(pE);
  24 draw(pD--pE);
  25
  26 point A_ = (pD-t.A)*2+t.A; dot("$A'$", A_, NE);
  27 draw(t.B--A_--t.C, dashed);
  28 draw(t.A--A_, dashed);
  29
  30 point E_ = midpoint(line(t.B,A_)); dot(Label("$E'$", E_, E));
  31 draw(E_--pD, dashed);
  32 """]]
  33 """]]
  34
  35 This plugin uses the [[!cpan Digest::SHA]] perl module.
  36
  37 The full source code is:
  38
  39         #! /usr/bin/perl
  40
  41         package IkiWiki::Plugin::asymptote;
  42         use warnings;
  43         use strict;
  44         use Digest::MD5 qw(md5_hex);
  45         use File::Temp qw(tempdir);
  46         use HTML::Entities;
  47         use Encode;
  48         use IkiWiki 3.00;
  49
  50         sub import {
  51                 hook(type => "getsetup", id => "asymptote", call => \&getsetup);
  52                 hook(type => "preprocess", id => "asymptote", call => \&preprocess);
  53         }
  54
  55         sub getsetup () {
  56                 return
  57                         plugin => {
  58                                 safe => 1,
  59                                 rebuild => undef,
  60                                 section => "widget",
  61                         },
  62         }
  63
  64         sub preprocess (@) {
  65                 my %params = @_;
  66
  67                 my $code = $params{src};
  68                 if (! defined $code && ! length $code) {
  69                         error gettext("missing src attribute");
  70                 }
  71                 return create($code, \%params);
  72         }
  73
  74         sub create ($$$) {
  75                 # This function calls the image generating function and returns
  76                 # the <img .. /> for the generated image.
  77                 my $code = shift;
  78                 my $params = shift;
  79
  80                 my $digest = md5_hex(Encode::encode_utf8($code));
  81
  82                 my $imglink= $params->{page} . "/$digest.png";
  83                 my $imglog =  $params->{page} .  "/$digest.log";
  84                 will_render($params->{page}, $imglink);
  85                 will_render($params->{page}, $imglog);
  86
  87                 my $imgurl=urlto($imglink, $params->{destpage});
  88                 my $logurl=urlto($imglog, $params->{destpage});
  89
  90                 if (-e "$config{destdir}/$imglink" ||
  91                     gen_image($code, $digest, $params->{page})) {
  92                         return qq{<img src="$imgurl}
  93                                 .(exists $params->{alt} ? qq{" alt="} . $params->{alt} : qq{})
  94                                 .qq{" class="asymptote" />};
  95                 }
  96                 else {
  97                         error qq{<a href="$logurl">}.gettext("failed to generate image from code")."</a>";
  98                 }
  99         }
 100
 101         sub gen_image ($$$$) {
 102                 # Actually creates the image.
 103                 my $code = shift;
 104                 my $digest = shift;
 105                 my $imagedir = shift;
 106
 107                 my $tmp = eval { create_tmp_dir($digest) };
 108                 if (! $@ &&
 109                     writefile("$digest.asy", $tmp, $code) &&
 110                     writefile("$imagedir/$digest.png", $config{destdir}, "") &&
 111                     system("asy -render=2 -offscreen -f png -o $config{destdir}/$imagedir/$digest.png $tmp/$digest.asy &>$tmp/$digest.log") == 0
 112                    ) {
 113                         return 1;
 114                 }
 115                 else {
 116                         # store failure log
 117                         my $log="";
 118                         {
 119                                 if (open(my $f, '<', "$tmp/$digest.log")) {
 120                                         local $/=undef;
 121                                         $log = <$f>;
 122                                         close($f);
 123                                 }
 124                         }
 125                         writefile("$digest.log", "$config{destdir}/$imagedir", $log);
 126
 127                         return 0;
 128                 }
 129         }
 130
 131         sub create_tmp_dir ($) {
 132                 # Create a temp directory, it will be removed when ikiwiki exits.
 133                 my $base = shift;
 134
 135                 my $template = $base.".XXXXXXXXXX";
 136                 my $tmpdir = tempdir($template, TMPDIR => 1, CLEANUP => 1);
 137                 return $tmpdir;
 138         }
 139
 140         1
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