{% if page.author != null %}
{% assign author = site.authors | find: "name", page.author | first %}
{% comment %} page author is not null {% endcomment %}
{% else %}
{% assign author = site.authors | find: "name", site.author | first %}
{% comment %} page author is null revert to {{ site.author }} {% endcomment %}
{% endif %}
{% unless author.social.linkedin == null %}
{% endunless %}
{% unless author.social.twitter == null %}
{% endunless %}
{% unless author.social.medium == null %}
{% endunless %}