get_cache_expiration
- EquationPlugin.get_cache_expiration(request, instance, placeholder)
Provides hints to the placeholder, and in turn to the page for determining the appropriate Cache-Control headers to add to the HTTPResponse object.
- Must return one of:
None: This means the placeholder and the page will not even consider this plugin when calculating the page expiration;
A TZ-aware datetime of a specific date and time in the future when this plugin’s content expires;
A datetime.timedelta instance indicating how long, relative to the response timestamp that the content can be cached;
An integer number of seconds that this plugin’s content can be cached.
- There are constants are defined in cms.constants that may be helpful:
EXPIRE_NOW
MAX_EXPIRATION_TTL
An integer value of 0 (zero) or EXPIRE_NOW effectively means “do not cache”. Negative values will be treated as EXPIRE_NOW. Values exceeding the value MAX_EXPIRATION_TTL will be set to that value.
Negative timedelta values or those greater than MAX_EXPIRATION_TTL will also be ranged in the same manner.
Similarly, datetime values earlier than now will be treated as EXPIRE_NOW. Values greater than MAX_EXPIRATION_TTL seconds in the future will be treated as MAX_EXPIRATION_TTL seconds in the future.