youtube.html

{% if include.content contains  "<code>" %}
    {% assign base_url = include.content | remove: "<code>" | remove: "</code>" |  split: "/" | last %}
{% else %}
    {% assign url = include.content | remove: "</a>" | split: ">" | last %}
    {% assign base_url = url |  split: "/" | last %}
{% endif %}
<center>
    <iframe width="560" height="315" src="https://www.youtube.com/embed/{{base_url}}" frameborder="0" allowfullscreen></iframe>
</center>