As I understand, this is how browser caching works. Assuming, a far future header has been set to let's say a year and foo.js is set to be cached. Here are some scenarios:
First visit to the page, server returns 200 and foo.js is cached for a year.
Next visit, browser checks the cache but has to check the server if foo.js has been modified. If not, server returns a 304 - Not Modified.
User is already on the page (and foo.js is in cache) clicks a link to go to another page, browser looks at the cached version of foo.js and serves it without doing a roundtrip to the server and returns a 200 (Cached).
User is already on the page (and foo.js is in cache) and for some reason hits F5/Reload, browser checks the cache but has to do a round trip to the server and check if foo.js has been modified. If not, server returns a 304.
As you can see, whenever a page is refreshed, it will always have to do a trip to the server to check if the file has been modified or not. I know this is not a lot and server will only return the header info but a round trip time in some cases are extremely important.
The question is, is there a way I can avoid this since I'm already setting the expiration for the files. I just want it to always fetch it from the cache until the expiration has expired or replace the file with something else (by versioning it).
