Allows use of template logic in a with-style template tag, for lazily saving the results of template logic that can be costly performance-wise. Due to django template parsing {% %} must be replaced with {[ ]} inside variable logic.
Example usage:
{% load variable %}
{% variable example="{[ if something ]}{{ somethingelse }}{[ else ]}{{ anotherthing }}{[ endif ]}" %}
{% for item in items %}
{{ example }}
{% endfor %}
{% endvariable %}