[OpenLayers-Dev] read-only TileCache
Tim Schaub
noreply at geocartic.com
Tue Apr 3 18:43:25 EDT 2007
Ehud Shabtai wrote:
> Is it possible to use the error handler to request the tile again but
> this time from the tilecache server? This would allow fast access to
> existing tiles, without requiring the whole cache to be available.
>
> If I remember correctly that's how Ka-Map works if you have a web
> accessible cache.
>
Well, both TileCache (meaning tilecache.cgi) and ka-Map (meaning
tile.php) check to see if a tile exists in the cache first. If the tile
exists, it is returned - if not, one is created.
If you are interested in having users create your cache for you, then it
is best to use TileCache directly (through tilecache.cgi). The
OpenLayers.Layer.TileCache option is really only for cases where a
disk-based cache is already created and you want to give users fast
access to the tiles.
That said, if you wanted to create a client-side image error handler
that redirected users to tilecache.cgi, it is certainly possible.
Tim
Also - you can configure ka-Map with the "tile_source" "cache" option.
This makes the client side function like the OpenLayers.Layer.TileCache
layer - requesting the images directly. Last time I checked, there
wasn't anything built in to switch to tile.php if this request failed.
Could be though.
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