doc/plugins/asymptote.mdwn

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