61 lines
2.3 KiB
Plaintext
61 lines
2.3 KiB
Plaintext
---
|
|
layout: default
|
|
title: Captioning Jekyll highlighted code block
|
|
date: 2023-05-27 19:22 +0200
|
|
tags: Ruby Jekyll
|
|
---
|
|
Jekyll encloses code highlighted with @{% raw %}{% highlight_ %}{% endraw %}@
|
|
Liquid tag inside @<figure>@ HTML tag. That in turn allows embeeding
|
|
@<figcaption>@ tag and captioning code, e.g. with file path. Jekyll (v4.3.2)
|
|
does not provide captioning, but can be extended with simple plugin.
|
|
|
|
Plugin code presented here and used by this blog is
|
|
"here.":https://gitea.michalczyk.pro/michalczyk.pro/blog/src/branch/master/_plugins/highlight-caption-option.rb
|
|
|
|
The plugin overrides @Jekyll::Tags::HighlightBlock.render()@ method. HTML
|
|
code returned by this method can be manipulated using parser library like
|
|
_Nokogiri_, but inserting a single tag is simple enough to be succesfully
|
|
performed without additional libraries:
|
|
|
|
{% highlight ruby caption=_plugins/highlight-caption-option.rb %}
|
|
module HighlightCaption
|
|
...
|
|
|
|
def render(*args)
|
|
caption = "<figcaption>#{@highlight_options[:caption]}</figcaption>"
|
|
|
|
match = super.match('<figure[^>]*>')
|
|
match.pre_match + match.to_s + caption + match.post_match
|
|
end
|
|
end
|
|
{% endhighlight %}
|
|
|
|
Caption generating code can be freely modified. It can even
|
|
process additional options passed to @{% raw %}{% highlight %}{% endraw %}@ tag.
|
|
Options are only allowed to consist of alphanumeric characters and underscore.
|
|
Passing file path as option requires loosening this restriction. We allow any
|
|
"non-blank character":https://ruby-doc.org/current/Regexp.html, except those
|
|
used to control option format (options are allowed to be expressed as: _name_,
|
|
_name=value_ and _name="quoted list"_)
|
|
|
|
{% highlight ruby caption=_plugins/highlight-caption-option.rb %}
|
|
module HighlightCaption
|
|
def self.prepended(mod)
|
|
syntax = mod.send(:remove_const, :SYNTAX).source.gsub('\\w', '[^[:^graph:]"=]')
|
|
mod.const_set(:SYNTAX, Regexp.new(syntax))
|
|
options = mod.send(:remove_const, :OPTIONS_REGEX).source.gsub('\\w', '[^[:^graph:]"=]')
|
|
mod.const_set(:OPTIONS_REGEX, Regexp.new(options))
|
|
end
|
|
|
|
...
|
|
end
|
|
{% endhighlight %}
|
|
|
|
Finally the modifications have to be @prepend@-ed to original class:
|
|
|
|
{% highlight ruby caption=_plugins/highlight-caption-option.rb %}
|
|
Jekyll::Hooks.register :site, :pre_render do |site|
|
|
Jekyll::Tags::HighlightBlock.prepend JekyllTagsExtensions::HighlightCaption
|
|
end
|
|
{% endhighlight %}
|