How to make an if-modified-since request?

Question

I'm coding a RSS feed reader that shows push notification each time the feed updates.

How can I do an If-modified-since request to the news site?

You can't do that. But what you definitely can do is to store the last modify date of your last fetch, and you can use a HTTP HEAD request to check that your feed is modified or not since your last download. — m4gic, Sep 01 '18 at 10:18

score 0 · Answer 1 · edited Oct 07 '21 at 11:21

You can add an "If-modified-since" header to the HTTP GET request. For more information:

But note there are some caveats:

The server may simply not implement this feature.
The server may not record a "last modified" time for the resource you are attempting to GET.
The server's clock may be skewed ....

1 Answers1