compare_modified_date Twig function

The compare_modified_date function allows you compare the modified on date for the page with the "If-Modified-Since" header in the request to see if a "304 Not Modified" http status code should be returned. If the "If-Modified-Since" date sent from the browser in the request is the same as the "last modified" date of the page then a 304 http status code is automatically set, no content is returned and the response is sent.

This function is unique to Aptuitiv. It is not part of the core Twig functionality.

{% do compare_modified_date() %}

This is often used with the header function in a template to set the page to be cached in the browser.

{# Tell the browser to cache something for 30 days #}
{% set expiry = now|date_modify('+30 days') %}
{% do header('Cache-Control: max-age=' ~ (expiry.timestamp - now.timestamp)) %}
{% do header('Pragma: cache') %}
{% do header('Expires: ' ~ expiry|date('D, d M Y H:i:s', 'GMT') ~ ' GMT') %}

{# NORMAL HTML TO GET/DISPLAY CONTENT #}

{# At the end of the template compare the modified date. Need to wait until the end so that the modified date is retrieved from the content for the page #}
{% do compare_modified_date() %}

Arguments

The compare_modified_date function has the following signature.

compare_modified_date()