A few things have changed in Jekyll 4.
Before we dive in, you need to have at least Ruby 2.4.0 installed.
Run the following in your terminal to check
ruby -v ruby 2.6.2p47 (2019-03-13 revision 67232) [x86_64-darwin18]
If you’re using a supported Ruby version > 2.4.0, go ahead and fetch the latest version of Jekyll:
gem update jekyll
post_urlTag and Baseurl
post_url tag now incorporates the
relative_url filter within itself
and therefore automatically prepends your site's
baseurl to the post's
Please ensure that you change all instances of the
post_url usage as following:
We’ve slightly altered the way Jekyll parses and renders your various templates to improve the overall build times. Jekyll now parses a template once, caches it internally and then renders the parsed template multiple times as required by your pages and documents.
The downside to this is that some of the community-authored plugins may not work as they previously used to.
If your plugin depends on the following code:
note that the return value (
template, an instance of
Liquid::Template), from that line will
always be the same object for a given
template instance is then rendered as previously, with respect to the
payload passed to it.
You’ll therefore have to ensure that
payload is not memoized or cached in your plugin instance.
If its a requirement that
template you get from the above step be different at all times,
you can invoke
- template = site.liquid_renderer.file(path).parse(content) + template = Liquid::Template.parse(content)
We’ve enhanced our default exclusion array. It now looks like the following:
# default excludes exclude: - .sass-cache/ - .jekyll-cache/ - gemfiles/ - Gemfile - Gemfile.lock - node_modules/ - vendor/bundle/ - vendor/cache/ - vendor/gems/ - vendor/ruby/
What’s new is that this array does not get overridden by the
in the user’s config file anymore. The user’s exclude entries simply get
added to the above default array (if the entry isn’t already excluded).
To forcibly “process” directories or files that have been excluded, list them
include array instead:
# overrides your excluded items configuration and the default include array ([".htaccess"]) include: - .htaccess - node_modules/uglifier/index.js
The above configuration directs Jekyll to handle only
node_modules/uglifier/index.js while ignoring every other file in the
node_modules directory since that directory is “excluded” by default.
Note that the default
include array still gets overridden by the
array in your config file. So, be sure to add
.htaccess to the list if you
need that file to be present in the generated site.
Jekyll has dropped support for
kramdown requires specific extensions to be additionally installed to use
certain features are desired outside of kramdown’s core functionality.
Out of all the extensions listed in the report linked above, gem
kramdown-parser-gfm is automatically installed along with Jekyll 4.0. The
remaining extensions will have to be manually installed by the user depending on
desired funtionality, by listing the extension’s gem-name in their
kramdown-converter-pdf will be ignored by Jekyll Core. To have Jekyll convert Markdown to PDF
you’ll have to depend on a plugin that subclasses
Jekyll::Converter with the
module Jekyll External.require_with_graceful_fail "kramdown-converter-pdf" class Markdown2PDF < Converter safe true priority :low def matches(ext) # match only files that have an extension exactly ".markdown" ext =~ /^\.markdown$/ end def convert(content) Kramdown::Document.new(content).to_pdf end def output_ext ".pdf" end end end
Vendors that provide a versioned Jekyll Environment Image (e.g. Docker Image, GitHub Pages, etc) will have to manually whitelist kramdown’s extension gems in their distributions for Jekyll 4.0.