Jekyll head logic for meta tags

head.html

<!-- Schema.org markup for Google+ -->
  {% if page.title %}
    <meta itemprop="name" content="{{ page.title }}">
  {% else %}
    <meta itemprop="name" content="{{ site.title }}">
  {% endif %}

  {% if page.description %}
    <meta itemprop="description" content="{{ page.description }}">
  {% else %}
    <meta itemprop="description" content="{{ site.description }}">
  {% endif %}
  {% if page.image %}
    <meta itemprop="image" content="{{ site.url }}/assets/images/social/og/{{ page.image }}.jpg">
  {% else %}
    <meta itemprop="image" content="{{ site.url }}/assets/og.jpg">
  {% endif %}

  <!-- Twitter Card data -->
  <meta name="twitter:card" content="summary_large_image">
  <meta name="twitter:site" content="@CullanLuther">
  {% if page.title %}
    <meta name="twitter:title" content="{{ page.title }}">
  {% else %}
    <meta name="twitter:title" content="{{ site.title }}">
  {% endif %}
  {% if page.description %}
    <meta name="twitter:description" content="{{ page.description }}">
  {% else %}
    <meta name="twitter:description" content="{{ site.description }}">
  {% endif %}
  <meta name="twitter:creator" content="@CullanLuther">
  <!-- Twitter summary card with large image must be at least 280 x 150 -->
  {% if page.image %}
    <meta name="twitter:image:src" content="{{ site.url }}/assets/images/social/twitter/{{ page.image }}.jpg">
  {% else %}
    <meta name="twitter:image:src" content="{{ site.url }}/assets/images/og.jpg">
  {% endif %}

  <!-- Open Graph -->
   <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 %}
    <!-- Facebook summary card with large image must be at least 1200 x 630 -->
    {% if page.image %}
      <meta content="{{ site.url }}/assets/images/social/og/{{ page.image }}.jpg" property="og:image">
    {% else %}
      <meta content="{{ site.url }}/assets/images/og.jpg" 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 %}