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