Upgrading from 2.x to 3.x
Upgrading from an older version of Jekyll? A few things have changed in 3.0 that you’ll want to know about.
Before we dive in, go ahead and fetch the latest version of Jekyll:
Diving in
Want to get a new Jekyll site up and running quickly? Simply
run jekyll new SITENAME
to create a new folder with a bare bones
Jekyll site.
site.collections has changed
In 2.x, your iterations over site.collections
yielded an array with the collection
label and the collection object as the first and second items, respectively. In 3.x,
this complication has been removed and iterations now yield simply the collection object.
A simple conversion must be made in your templates:
collection[0]
becomescollection.label
collection[1]
becomescollection
When iterating over site.collections
, ensure the above conversions are made.
Dropped dependencies
We dropped a number of dependencies the Core Team felt were optional. As such, in 3.0, they must be explicitly installed and included if you use any of the features. They are:
- jekyll-paginate – Jekyll’s pagination solution from days past
- jekyll-coffeescript – processing of CoffeeScript
- jekyll-gist – the
gist
Liquid tag - pygments.rb – the Pygments highlighter
- redcarpet – the Markdown processor
- toml – an alternative to YAML for configuration files
- classifier-reborn – for
site.related_posts
Future posts
A seeming feature regression in 2.x, the --future
flag was automatically enabled.
The future flag allows post authors to give the post a date in the future and to have
it excluded from the build until the system time is equal or after the post time.
In Jekyll 3, this has been corrected. Now, --future
is disabled by default.
This means you will need to include --future
if you want your future-dated posts to
generate when running jekyll build
or jekyll serve
.
Layout metadata
Introducing: layout
. In Jekyll 2 and below, any metadata in the layout was munged onto
the page
variable in Liquid. This caused a lot of confusion in the way the data was
merged and some unexpected behaviour. In Jekyll 3, all layout data is accessible via layout
in Liquid. For example, if your layout has class: my-layout
in its YAML front matter,
then the layout can access that via {{ layout.class }}
.
Syntax highlighter changed
For the first time, the default syntax highlighter has changed for the
highlight
tag and for backtick code blocks. Instead of Pygments.rb,
it’s now Rouge. If you were using the highlight
tag with certain
options, such as hl_lines
, they may not be available when using Rouge. To
go back to using Pygments, set highlighter: pygments
in your
_config.yml
file and run gem install pygments.rb
or add
gem 'pygments.rb'
to your project’s Gemfile
.
Relative Permalink support removed
In Jekyll 3 and above, relative permalinks have been deprecated. If you created your site using Jekyll 2 and below, you may receive the following error when trying to serve or build:
This can be fixed by removing the following line from your _config.yml
file:
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