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Google Chrome does not honor cache-policy in page header if the page is displayed in a FRAME

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+1 A:

Did you try those meta tags in both the framed document as well as the parent/hosting document?

Chris 2010-05-09 16:24:09

Yes, expiration policy is in framset doc and in the content docs too. The document with the frameset declaration <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Frameset//EN" "http://www.w3.org/TR/html4/frameset.dtd"> does get reloaded. Chrome audit remarks that the frameset page is "explicitly non-cacheable. Consider making [it] cacheable if possible". The content docs never get reloaded. The first time I loaded them in Chrome they did not have meta tags controlling their expiration. Even though I have since added these tags and re-uploaded, Chrome seems to have cached them in perpetuity.

Tim 2010-05-09 16:39:54

I see. The only way I can think to address this is perhaps an unappealing one: to specify an argument on your frame SRC to break the cache: iframe src="document.html?x=new". Or, if you have the luxury of using server-side script such as asp.net ?t=<%=DateTime.Now.Ticks%> The document would ignore the argument, but chrome would see it as a different URL. But I realize for a number of reasons this is unappealing.

Chris 2010-05-09 16:49:55

Thanks. I went back and hard-coded an argument to force a reload. Even though the argument won't change because it's hard-coded, Chrome is now honoring the policy in the meta tags. So apparently the undesirable behavior is this: if the page had no cache/expiration policy the first time it was loaded, Chrome will continue to cache it even if such a policy is later added to the page. Either Chrome doesn't look for a policy if the page had none to begin with, or the NULL or UNDEFINED original expiration date is messing up the comparison with the new expiration date in some way.

Tim 2010-05-09 18:22:55

It would have to fetch the file from the server to see your new meta tags, which would defeat the concept of caching, right? Seems like there is no other way than the way it is working now?

Chris 2010-05-09 19:11:08

Moreover, this problem may only affect documents first loaded into Chrome quite a while ago; perhaps the lack of an expiration date is now being stored differently than it used to be. Tests with documents created today show that Chrome is honoring the meta tags.

Tim 2010-05-09 19:35:02

But Audit warns that a page lacking an explicit cache policy may NOT be cached, rather than perpetually cached.

Tim 2010-05-09 19:36:10

Ah, I see. If my answer helped you and you don't anticipate getting more responses I would appreciate it if you would mark this as an answer. :)

Chris 2010-05-09 22:08:34

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Google Chrome does not honor cache-policy in page header if the page is displayed in a FRAME

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