How to create a Jekyll custom tag that injects Google Ads into posts

AdsInlineTag.rb

# http://www.createdbypete.com/articles/create-a-custom-liquid-tag-as-a-jekyll-plugin/
class AdsInlineTag < Liquid::Tag
  def initialize(tag_name, input, tokens)
    super
    @input = input
  end

  def lookup(context, name)
    lookup = context
    name.split(".").each { |value| lookup = lookup[value] }
    lookup
  end

  def render(context)
    <<-MARKUP.strip
    <div style="width: 728px; margin: 0 auto; padding: .8em 0;">
      <script async src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script>
        <ins class="adsbygoogle" style="display:block" data-ad-client="ca-pub-2754843202551236" data-ad-slot="2662611504" data-ad-format="auto"></ins><script>(adsbygoogle = window.adsbygoogle || []).push({});</script></div>
    MARKUP
  end
  
  def split_params(params)
    params.split("|")
  end
end

Liquid::Template.register_tag('ads', AdsInlineTag)

Replace everything between <<-MARKUP.strip and MARKUP with your own Ad-code.

Then just use {% ads %} to inject the ads code into the right locations in your post.

Hi - you might want to modify the render method as follows:

  def render(context)
    source = <<-MARKUP.strip
    <div style="width: 728px; margin: 0 auto; padding: .8em 0;">
      <script async src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script>
        <ins class="adsbygoogle" style="display:block" data-ad-client="ca-pub-2754843202551236" data-ad-slot="2662611504" data-ad-format="auto"></ins><script>(adsbygoogle = window.adsbygoogle || []).push({});</script></div>
    MARKUP
    source = TemplateWrapper::safe_wrap(source)
  end

I was having an issue with the add showing up as a text being formatted by RDiscount - TemplateWrapper::safe_wrap prevents this.