blob: 7da565043d114b857a29e31562ca564f60d689a3 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
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
|
require 'rouge/plugins/redcarpet'
module Banzai
module Filter
# HTML Filter to highlight fenced code blocks
#
class SyntaxHighlightFilter < HTML::Pipeline::Filter
def call
doc.search('pre > code').each do |node|
highlight_node(node)
end
doc
end
def highlight_node(node)
language = node.attr('lang')
code = node.text
css_classes = "code highlight"
lexer = lexer_for(language)
lang = lexer.tag
begin
code = Rouge::Formatters::HTMLGitlab.format(lex(lexer, code), tag: lang)
css_classes << " js-syntax-highlight #{lang}"
rescue
lang = nil
# Gracefully handle syntax highlighter bugs/errors to ensure
# users can still access an issue/comment/etc.
end
highlighted = %(<pre class="#{css_classes}" lang="#{lang}" v-pre="true"><code>#{code}</code></pre>)
# Extracted to a method to measure it
replace_parent_pre_element(node, highlighted)
end
private
# Separate method so it can be instrumented.
def lex(lexer, code)
lexer.lex(code)
end
def lexer_for(language)
(Rouge::Lexer.find(language) || Rouge::Lexers::PlainText).new
end
def replace_parent_pre_element(node, highlighted)
# Replace the parent `pre` element with the entire highlighted block
node.parent.replace(highlighted)
end
end
end
end
|