Adding Open Graph Tags to Jekyll

adding-open-graph-tags-to-jekyll.html

<meta content="{{ site.title }}" property="og:site_name">
{% if page.title %}
  <meta content="{{ page.title }}" property="og:title">
{% else %}
  <meta content="{{ site.title }}" property="og:title">
{% endif %}
{% if page.title %}
  <meta content="article" property="og:type">
{% else %}
  <meta content="website" property="og:type">
{% endif %}
{% if page.description %}
  <meta content="{{ page.description }}" property="og:description">
{% else %}
  <meta content="{{ site.description }}" property="og:description">
{% endif %}
{% if page.url %}
  <meta content="{{ site.url }}{{ page.url }}" property="og:url">
{% endif %}
{% if page.date %}
  <meta content="{{ page.date | date_to_xmlschema }}" property="article:published_time">
  <meta content="{{ site.url }}/about/" property="article:author">
{% endif %}
{% if page.image %}
  <meta content="{{ site.url }}/assets/img/posts/{{ page.image }}" property="og:image">
{% else %}
  <meta content="{{ site.url }}/assets/img/logo-high-resolution.png" property="og:image">
{% endif %}
{% if page.categories %}
  {% for category in page.categories limit:1 %}
  <meta content="{{ category }}" property="article:section">
  {% endfor %}
{% endif %}
{% if page.tags %}
  {% for tag in page.tags %}
  <meta content="{{ tag }}" property="article:tag">
  {% endfor %}
{% endif %}

Line 18:

   <meta content="{{ site.url }}{{ page.url }}" property="og:url">

Jekyll sites can be hosted at a path deeper than the domain root (e.g. GitHub Project Pages are at <username>.github.io/<projectname>), which is usually indicated with site.baseurl. For maximum generality, I would recommend, for Jekyll 3.3 and later, that this line be changed to:

   <meta content="{{ page.url | absolute_url }}" property="og:url">

and for earlier versions of Jekyll that don't support the absolute_url filter,

   <meta content="{{ site.url | append: site.baseurl | append: page.url }}" property="og:url">