I'm using the RSS feed of the "latest activity" to publish an activity log of my Ning site onto an external website. I got the URL of my feed by clicking the RSS button at the bottom of the Latest Activity section on my network's main page, and it looks like this:
http://[network].ning.com/activity/log/list?fmt=rss
By performing an action on my network, like replying to a discussion, and then refreshing that URL, I can see that there is some caching going on within Ning. The new activity does not show up in the feed, although it does show up on my site's main page. I'm not sure how long it takes to show up in the feed, but it is more than just a few minutes anyway.
I noticed that if I add another parameter into the URL, just something meaningless, then I can get the updated feed. I certainly don't want to have a random number in there in order to bust the cache for each request, but depending on how long the page is cached, I might have to do something.
Is there anywhere I can find out how long the page is cached for, other than by observation?
If the caching period is longer than I can live with, Is there an "accepted" way of handling this issue? My current plan is to put some logic in my PHP page that requests and parses the activity feed, to create a URL parameter based on the current time, and that way I can have it rotate to a new parameter every x minutes.