disable php cache control

[butonic]

Had to prevent PHP from sending cache control headers. Otherwise the dav previews from #29319 always had to reload the previews because Chrome respects the Pragma:nocache header that is sent by default.

Related: #26922 (comment)

[DeepDiver1975]

http://php.net/manual/fa/session.configuration.php#ini.session.cache-limiter shouldn't that be a string?

[butonic]

yes but php_value session.cache_limiter '' leads to a 500 status and .htaccess: php_value takes two arguments, PHP Value Modifier in the apache error log. 0 seems to work

[DeepDiver1975]

what about environments where htaccess is not in place?
should we add this to base.php?

[butonic]

maybe base.php is a better place ... all app framework routes already handle cache control headers

[mmattel]

@butonic any update on this ?

[PVince81]

=> base.php or Webdav plugin layer ? @DeepDiver1975 @butonic

decide and then we can take over and reassign

[butonic]

To clarify, the php docs on session_cache_limiter say

Setting the cache limiter to '' will turn off automatic sending of cache headers entirely.

In general, we are managing the cache control headers ourself in the app framework Response https://github.com/owncloud/core/blob/v10.1.0/lib/public/AppFramework/Http/Response.php#L49 or any derived class. So disabling cache management in php is the right thing to do, because it might otherwise cause unwanted caching.

However, setting it to '' in the .htaccess produces a 500 error, so I tried 0 and it worked. It seems Drupal is using none to do the same thing. Maybe ^$ works as expected but might be even more cryptic.

I vote to disable php cache control in the base.php. It least we can then properly set it to ''.

[PVince81]

raised as #34441

if there is no particular criticality to this, the ticket will remain in backlog for later