Top Level Namespace

Defined Under Namespace

Modules: Jektex, JekyllCustomPermalink

Constant Summary collapse

PATH_TO_JS = 
"./katex.min.js"
CACHE_DIR = 
"./.jektex-cache/"
CACHE_FILE = 
"jektex-cache.marshal"
PATH_TO_CACHE = 
CACHE_DIR + CACHE_FILE
KATEX = 
ExecJS.compile(open(PATH_TO_JS).read)
PARSE_ERROR_PLACEHOLDER = 
"<b style='color: red;'>PARSE ERROR</b>"

Instance Method Summary collapse

Instance Method Details

#convert(doc) ⇒ Object 



16
17
18
19
20
21
22
 
# File 'lib/jektex/jektex.rb', line 16

def convert(doc)
  # convert HTML enetities back to characters
  post = HTMLEntities.new.decode(doc.to_s)
  post = post.gsub(/(\\\()((.|\n)*?)(?<!\\)\\\)/) { |m| escape_method($1, $2, doc.path) }
  post = post.gsub(/(\\\[)((.|\n)*?)(?<!\\)\\\]/) { |m| escape_method($1, $2, doc.path) }
  return post
end

#escape_method(type, string, doc_path) ⇒ Object 



24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
 
# File 'lib/jektex/jektex.rb', line 24

def escape_method( type, string, doc_path )
  @display = false

  # detect if expression is display view
  case type.downcase
    when /\(/
      @display = false
    else /\[/
      @display = true
  end

  # generate a hash from the math expression
  @expression_hash = Digest::SHA2.hexdigest(string) + @display.to_s

  # use it if it exists
  if($cache.has_key?(@expression_hash))
    $count_newly_generated_expressions += 1
    print_stats
    return $cache[@expression_hash]

  # else generate one and store it
  else
    # create the cache directory, if it doesn't exist
    begin
      # render using ExecJS
      @result =  KATEX.call("katex.renderToString", string, 
                          {displayMode: @display,  macros: $global_macros})
    rescue SystemExit, Interrupt
      # save cache to disk
      File.open(PATH_TO_CACHE, "w"){|to_file| Marshal.dump($cache, to_file)}
      # this stops jekyll being immune to interupts and kill command
      raise
    rescue Exception => e
      # catch parse error
      puts "\e[31m " + e.message.gsub("ParseError: ", "") + "\n\t"  + doc_path + "\e[0m"
      return PARSE_ERROR_PLACEHOLDER
    end
    # save to cache
    $cache[@expression_hash] = @result
    # update count of newly generated expressions
    $count_newly_generated_expressions += 1
    print_stats
    return @result
  end
end

#print_stats ⇒ Object 



70
71
72
73
74
75
76
 
# File 'lib/jektex/jektex.rb', line 70

def print_stats
  print "             LaTeX: " + 
        ($count_newly_generated_expressions).to_s + 
        " expressions rendered (" + $cache.size.to_s + 
        " already cached)        \r"
  $stdout.flush
end