Templates

Jekyll uses the Liquid templating language to process templates. All of the standard Liquid tags and filters are supported. Jekyll even adds a few handy filters and tags of its own to make common tasks easier.

Filters

Description Filter and Output

Date to XML Schema

Convert a Date into XML Schema (ISO 8601) format.

{{ site.time | date_to_xmlschema }}

2008-11-07T13:07:54-08:00

Date to RFC-822 Format

Convert a Date into the RFC-822 format used for RSS feeds.

{{ site.time | date_to_rfc822 }}

Mon, 07 Nov 2008 13:07:54 -0800

Date to String

Convert a date to short format.

{{ site.time | date_to_string }}

07 Nov 2008

Date to Long String

Format a date to long format.

{{ site.time | date_to_long_string }}

07 November 2008

Where

Select all the objects in an array where the key has the given value.

{{ site.members | where:"graduation_year","2014" }}

Group By

Group an array's items by a given property.

{{ site.members | group_by:"graduation_year" }}

[{"name"=>"2013", "items"=>[...]}, {"name"=>"2014", "items"=>[...]}]

XML Escape

Escape some text for use in XML.

{{ page.content | xml_escape }}

CGI Escape

CGI escape a string for use in a URL. Replaces any special characters with appropriate %XX replacements.

{{ "foo,bar;baz?" | cgi_escape }}

foo%2Cbar%3Bbaz%3F

URI Escape

URI escape a string.

{{ "foo, bar \baz?" | uri_escape }}

foo,%20bar%20%5Cbaz?

Number of Words

Count the number of words in some text.

{{ page.content | number_of_words }}

1337

Array to Sentence

Convert an array into a sentence. Useful for listing tags.

{{ page.tags | array_to_sentence_string }}

foo, bar, and baz

Textilize

Convert a Textile-formatted string into HTML, formatted via RedCloth

{{ page.excerpt | textilize }}

Markdownify

Convert a Markdown-formatted string into HTML.

{{ page.excerpt | markdownify }}

Converting Sass/SCSS

Convert a Sass- or SCSS-formatted string into CSS.

{{ some_scss | scssify }} {{ some_sass | sassify }}

Slugify

Convert a string into a lowercase URL "slug" by replacing every sequence of spaces and non-alphanumeric characters with a hyphen.

{{ page.title | slugify }}

Data To JSON

Convert Hash or Array to JSON.

{{ site.data.projects | jsonify }}

Sort

Sort an array. Optional arguments for hashes: 1. property name 2. nils order (first or last).

{{ page.tags | sort }}

{{ site.posts | sort: 'author' }}

{{ site.pages | sort: 'title', 'last' }}

Tags

Includes

If you have small page fragments that you wish to include in multiple places on your site, you can use the include tag.

{% include footer.html %}

Jekyll expects all include files to be placed in an _includes directory at the root of your source directory. This will embed the contents of <source>/_includes/footer.html into the calling file.

ProTip™: Use variables as file name

The name of the file you wish to embed can be literal (as in the example above), or you can use a variable, using liquid-like variable syntax as in {% include {{my_variable}} %}.

You can also pass parameters to an include:

{% include footer.html param="value" %}

These parameters are available via Liquid in the include:

{{ include.param }}

Including files relative to another file

You can also choose to include file fragments relative to the current file:

{% include_relative somedir/footer.html %}

You won’t need to place your included content within the _includes directory. Instead, the inclusion is specifically relative to the file where the tag is being used. For example, if _posts/2014-09-03-my-file.markdown uses the include_relative tag, the included file must be within the _posts directory, or one of it’s subdirectories. You cannot include files in other locations.

All the other capaibilities of the include tag are available to the include_relative tag, such as using variables.

Code snippet highlighting

Jekyll has built in support for syntax highlighting of over 100 languages thanks to Pygments. To use Pygments, you must have Python installed on your system and set highlighter to pygments in your site’s configuration file.

Alternatively, you can use Rouge to highlight your code snippets. It doesn’t support as many languages as Pygments does but it should fit in most cases and it’s written in pure Ruby ; you don’t need Python on your system!

To render a code block with syntax highlighting, surround your code as follows:

{% highlight ruby %}
def foo
  puts 'foo'
end
{% endhighlight %}

The argument to the highlight tag (ruby in the example above) is the language identifier. To find the appropriate identifier to use for the language you want to highlight, look for the “short name” on the Pygments’ Lexers page or the Rouge wiki.

Line numbers

There is a second argument to highlight called linenos that is optional. Including the linenos argument will force the highlighted code to include line numbers. For instance, the following code block would include line numbers next to each line:

{% highlight ruby linenos %}
def foo
  puts 'foo'
end
{% endhighlight %}

Stylesheets for syntax highlighting

In order for the highlighting to show up, you’ll need to include a highlighting stylesheet. For an example stylesheet you can look at syntax.css. These are the same styles as used by GitHub and you are free to use them for your own site. If you use linenos, you might want to include an additional CSS class definition for the .lineno class in syntax.css to distinguish the line numbers from the highlighted code.

Post URL

If you would like to include a link to a post on your site, the post_url tag will generate the correct permalink URL for the post you specify.

{% post_url 2010-07-21-name-of-post %}

If you organize your posts in subdirectories, you need to include subdirectory path to the post:

{% post_url /subdir/2010-07-21-name-of-post %}

There is no need to include the file extension when using the post_url tag.

You can also use this tag to create a link to a post in Markdown as follows:

[Name of Link]({% post_url 2010-07-21-name-of-post %})

Gist

Use the gist tag to easily embed a GitHub Gist onto your site. This works with public or secret gists:

{% gist parkr/931c1c8d465a04042403 %}

You may also optionally specify the filename in the gist to display:

{% gist parkr/931c1c8d465a04042403 jekyll-private-gist.markdown %}