seo.html

<!-- begin _includes/seo.html -->
{%- if site.url -%}
  {%- assign seo_url = site.url | append: site.baseurl -%}
{%- endif -%}
{%- assign seo_url = seo_url | default: site.github.url -%}

{% assign title_separator = site.title_separator | default: '-' | replace: '|', '&#124;' %}

{%- if page.title -%}
  {%- assign seo_title = page.title | append: " " | append: title_separator | append: " " | append: site.title -%}
{%- endif -%}

{%- if seo_title -%}
  {%- assign seo_title = seo_title | markdownify | strip_html | strip_newlines | escape_once -%}
{%- endif -%}

{% if page.canonical_url %}
  {%- assign canonical_url = page.canonical_url %}
{% else %}
  {%- assign canonical_url = page.url | replace: "index.html", "" | absolute_url %}
{% endif %}

{%- assign seo_description = page.description | default: page.excerpt | default: site.description -%}
{%- if seo_description -%}
  {%- assign seo_description = seo_description | markdownify | strip_html | strip_newlines | escape_once -%}
{%- endif -%}

<!-- don't use page.author even if it is set, find author based on url -->
{% assign author = page.url | split: "/" %}
{% assign author = author[1] %}
{% assign author = site.data.authors.authors | where: "prefix", author | first %}

{%- if author.twitter -%}
  {%- assign author_twitter = author.twitter | replace: "@", "" -%}
{%- endif -%}

{%- assign page_large_image = page.og_image | default: author.og_image | default: author.avatar | default: page.overlay_image | default: page.header.image -%}
{%- unless page_large_image contains '://' -%}
  {%- assign page_large_image = page_large_image | absolute_url -%}
{%- endunless -%}
{%- assign page_large_image = page_large_image | escape -%}

{%- assign page_teaser_image = page.header.teaser | default: site.og_image -%}
{%- unless page_teaser_image contains '://' -%}
  {%- assign page_teaser_image = page_teaser_image | absolute_url -%}
{%- endunless -%}
{%- assign page_teaser_image = page_teaser_image | escape -%}

{%- assign site_og_image = site.og_image -%}
{%- unless site_og_image contains '://' -%}
  {%- assign site_og_image = site_og_image | absolute_url -%}
{%- endunless -%}
{%- assign site_og_image = site_og_image | escape -%}

{%- if page.date -%}
  {%- assign og_type = "article" -%}
{%- else -%}
  {%- assign og_type = "website" -%}
{%- endif -%}

<title>{{ seo_title | default: site.title }}{% if paginator %}{% unless paginator.page == 1 %} {{ title_separator }} {{ site.data.ui-text[site.locale].page | default: "Page" }} {{ paginator.page }}{% endunless %}{% endif %}</title>
<meta name="description" content="{{ seo_description }}">

{% if author.name %}
  <meta name="author" content="{{ author.name | default: author }}">
{% endif %}

<meta property="og:type" content="{{ og_type }}">
<meta property="og:locale" content="{{ site.locale | replace: "-", "_" | default: "en_US" }}">
<meta property="og:site_name" content="{{ site.title }}">