up.protocol
X-Up-Reload-From-Time
HTTP header
This feature has been deprecated. Read the standard If-Modified-Since request header instead.
Unpoly sends it when the fragment has a Last-Modified time. See conditional requests.
Load unpoly-migrate.js
to polyfill deprecated features.
This request header contains a timestamp of an existing fragment that is being reloaded.
The timestamp must be explicitly set by the user as an [up-time] attribute on the fragment.
It should indicate the time when the fragment's underlying data was last changed.
See [up-time] for a detailed example.
Format
The time is encoded as the number of seconds elapsed since the Unix epoch.
For instance, a modification date of December 23rd 2020, 1:40:18 PM UTC would produce the following header:
X-Up-Target: .unread-count
X-Up-Reload-From-Time: 1608730818
If no timestamp is known, Unpoly will send a value of zero (X-Up-Reload-From-Time: 0).