Get Jekyll Configuration Inside Plugin

Overview

You can access Jekyll config options in plugins with:

Jekyll.configuration({})['KEY_NAME']

If the config key contains nested levels, the format is:

Jekyll.configuration({})['KEY_LEVEL_1']['KEY_LEVEL_2']

Example

If a _config.yml contains:

testvar: new valuecustom_root:    second_level: sub level data

A basic example that simply outputs those values would look like:

require 'nokogiri'module Jekyll  module AssetFilter    def only_first_p(post)      @c_value = Jekyll.configuration({})['testvar']      @c_value_nested = Jekyll.configuration({})['custom_root']['second_level']      output = "<p>"      ### Confirm you got the config values      output << "<br />"      output << "c_value: " + @c_value + "<br />"      output << "c_value_nested: " + @c_value_nested + "<br />"      output << "<br />"      ###      output << Nokogiri::HTML(post["content"]).at_css("p").inner_html      output << %{</p><a class="readmore" href="#{post["url"]}">Read more</a>}      output    end  endendLiquid::Template.register_filter(Jekyll::AssetFilter)

Of course, you would want to put checks in that verify that the config key/values are defined before trying to use them. That's left as an exercise for the reader.

Another Possible Option

The "Liquid filters" section of the Jekyll Plugins Wiki Page contains the following:

In Jekyll you can access the site object through registers. As an example, you can access the global configuration (_config.yml) like this: @context.registers[:site].config['cdn'].

I haven't spent the time to get that to work, but it might be worth checking out as well.

Jekyll.configuration({})['KEY_NAME'] will break the --config command line option because it will always load the configurations from the _config.yml file. Another bad side effect is that it will read the _config.yml file again.

context.registers[:site].config['KEY_NAME'] is the correct answer because it will get the key from the configurations already loaded by Jekyll.

If you are working with Generators (which are also plugins), it is possible to get the configuration like this:

class MyPlugin < Jekyll::Generator  def generate(site)    puts site.config["max_posts"] # max_posts as defined in _config.yml

You'll get the site as an argument, and the .config is accessible as an hash.