really really refresh again
I started the stupid refresh question last month. Now I'm trying to use the Poll product as a starter/learner. I cannot get the images to refresh properly. I know about <!--# call "RESPONSE.setHeader( 'Expires', '0')"--> <!--# call "RESPONSE.setHeader( 'Pragma', 'no-cache')"--> and have tried putting these in the document containing the image. This has no obvious effect. This gif refresh problem must happen to others. Any ideas? -- Robin Becker
Robin Becker wrote I started the stupid refresh question last month. Now I'm trying to use the Poll product as a starter/learner. I cannot get the images to refresh properly. [..] This gif refresh problem must happen to others. Any ideas?
a) Find a baseball bat. Drive a couple of nails through the end. b) Now visit Netscape and Microsoft's browser development team, and ask them (using results from a), above) politely to actually look at the expires header for images. Alternately, hit shift-reload, or make sure you refer to the image as something like image.gif?timestamp=<curtime> in your page. Both the major browsers are incredibly stupid, and will cache images in a way that could best be described as "naughty". (On a related note - setting 'Pragma: no-cache' in a server _should_ have no effect. It's a client-set thing, to stop caches serving a cached copy). Anthony, in a hostile mood towards browser authors (see next post from me). -- Anthony Baxter <anthony@interlink.com.au> It's never too late to have a happy childhood.
In article <199907151233.WAA07348@mbuna.arbhome.com.au>, Anthony Baxter <anthony@interlink.com.au> writes
Robin Becker wrote I started the stupid refresh question last month. Now I'm trying to use the Poll product as a starter/learner. I cannot get the images to refresh properly. [..] This gif refresh problem must happen to others. Any ideas?
a) Find a baseball bat. Drive a couple of nails through the end. b) Now visit Netscape and Microsoft's browser development team, and ask them (using results from a), above) politely to actually look at the expires header for images.
Alternately, hit shift-reload, or make sure you refer to the image as something like image.gif?timestamp=<curtime> in your page.
yes I've come to this conclusion as well grrrhhhh!
Both the major browsers are incredibly stupid, and will cache images in a way that could best be described as "naughty".
(On a related note - setting 'Pragma: no-cache' in a server _should_ have no effect. It's a client-set thing, to stop caches serving a cached copy).
Anthony, in a hostile mood towards browser authors (see next post from me).
-- Robin Becker
Forget the Pragma. The server-side version of Pragma in Cache-Control. In other words: <!--#call "RESPONSE.setHeader('Cache-Control', 'no-cache')"--> Cache-Control has other options which allow you to fine-tune cache management, such as the max number of days for which the document should be considered valid (max-age and max-stale, iirc). -- Alexander Staubo http://www.mop.no/~alex/
-----Original Message----- From: zope-admin@zope.org [mailto:zope-admin@zope.org]On Behalf Of Robin Becker Sent: 15. juli 1999 13:44 To: zope@zope.org Subject: [Zope] really really refresh again
I started the stupid refresh question last month. Now I'm trying to use the Poll product as a starter/learner. I cannot get the images to refresh properly.
I know about
<!--# call "RESPONSE.setHeader( 'Expires', '0')"--> <!--# call "RESPONSE.setHeader( 'Pragma', 'no-cache')"-->
and have tried putting these in the document containing the image. This has no obvious effect.
This gif refresh problem must happen to others. Any ideas? -- Robin Becker
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On 15 Jul 1999 07:40:01 -0500, Robin Becker wrote:
I started the stupid refresh question last month. Now I'm trying to use the Poll product as a starter/learner. I cannot get the images to refresh properly.
I know about
<!--# call "RESPONSE.setHeader( 'Expires', '0')"--> <!--# call "RESPONSE.setHeader( 'Pragma', 'no-cache')"-->
and have tried putting these in the document containing the image. This has no obvious effect.
This gif refresh problem must happen to others. Any ideas?
The primary clients don't necessarily obey either the cache pragmas or the HTTP1.1 cache-control headers. The only solution I ever found was to change the image URL each time it was to be refreshed. Now at first, this seems like a major problem, however, especially in Zope, it isn't as much of a problem as might first appear if the URL references a method which simply returns the correct information. You could tag a parameter such as a timestamp (clipped within an allowable time frame) onto the method URL 'picb/56159' and possibly even ignore the timestamp information when the method retrieves the current image data. The image URL does need to be changed in the main document each time, but most clients can be coerced to reload the main document without much travail. Kent Polk
participants (4)
-
Alexander Staubo -
Anthony Baxter -
kent＠tiamat.goathill.org -
Robin Becker