{% load gravatar static %}

{% if gravatar_url %}
<img src="{% if user.email %}{% gravatar_url user.email image_size %}{% else %}{% gravatar_url 'tethys@example.com' image_size %}{% endif %}" alt="" width="{{ image_size }}" height="{{ image_size }}" class="d-inline-block align-text-top">
{% else %}
{% if user.email %}{% gravatar user.email image_size %}{% else %}{% gravatar "tethys@example.com" image_size %}{% endif %}
{% endif %}