On Fri, Jan 21, 2011 at 4:32 PM, IT Intern <[email protected]> wrote: > "GWC *can* be set up to cache multiple versions > of a layer based on the values in the STYLES= (or any other) wms > parameter, but that won't work if you are using truly dynamic styles; > for example if you let the user choose arbitrarily style parameters on > the client side and build an SLD from that." > > How come? What I mean to ask is that even if the user does pick the SLD and > it is built on the fly, wouldn't that SLD still have to be set-up in the > same format as that read from the file?
It's because GWC only knows how to do this caching by the actual WMS parameters. In this case the parameter is 'SLD' and its value is the URL to an SLD file. GWC won't actually retrieve and interpret the contents of that file though. If you can make your dynamic SLD always have a unique filename based on the file contents (perhaps using a SHA or MD5 hash of the contents as the filename) you could possibly make it work like you want. You would think this through carefully though because if you have a lot of varying styles being used you could start to fill your cache with stuff that is never used again, and if you have cache expiration set up it's possible that you might start pushing out things you WANT to save. I've generally found that caching is best for things like base maps that never change. Also, due to complications making labels work well with tiles it's usually best to not cache layers that have labels in them, unless you carefully place your labels. When I wrote LL-MAP we ended up caching the actual base maps, but the overlays with country borders & labels are done as a regular WMS layer. We also don't cache or tile user-generated maps for similar reasons (plus, those maps usually are usually very simple, and not worth the effort of making them work with the cache.) ------------------------------------------------------------------------------ Special Offer-- Download ArcSight Logger for FREE (a $49 USD value)! Finally, a world-class log management solution at an even better price-free! Download using promo code Free_Logger_4_Dev2Dev. Offer expires February 28th, so secure your free ArcSight Logger TODAY! http://p.sf.net/sfu/arcsight-sfd2d _______________________________________________ Geoserver-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geoserver-users
