[OpenLayers-Users] what does this error mean?

[Gregor Mosheh]

Ah, excellent. Again, Mr. Schmidt, you have saved my day.
    http://69.59.158.10/openlayers/

I did take an extra step, though, and change the MapServerLayer layers 
into WMSServer layers and pointed them at http://localhost/mapserv in 
the usual fashion. I presume that a wms driver will be slower than a 
mapfile driver, but I do enjoy the debugging ability and the 
pluggability for when we move the imagery hosting elsewhere. Besides, I 
plan to seed the cache anyway...

So thank you again!

Although my map now *works* I would like to go the extra step and 
*understand* what's going on here. I even volunteer to write up the Wiki 
page on what I had to go through, if this stuff isn't so obvious that 
it's not necessary. OL's FAQ entry about getting it to work with TC just 
says to read the README, so... :)

   [cities]
   debug=false
   extension=gif
   type=WMSLayer
   url=http://localhost/cgi-bin/mapserv?map=/maps/wms/wms.map
   layers=cities
   bbox=-124.15456,40.41142,-123.7844,40.61528
   maxResolution=1.40625

These last 2 are what fixed it, and are what I don't get.

Why would tilecache need to know the max extent? The WMS server will 
gladly serve up -180,-90,180,90 without an error (though of course 
Humboldt County isn't in fact visible). Is this a matter of OL making a 
request that TC refuses to serve, or what?

And what is the maxResolution used for on TC's part?



> Also, for your overlays, add a 'reproject: false' option if they're tc
> overlays:

Interesting; that does fix it and seems to be necessary. What does the 
reproject:false option accomplish? It wasn't necessary when I first set 
this stuff up and had it working, but evidently is necessary now...


-- 
Gregor Mosheh / Greg Allensworth
System Administrator, HostGIS cartographic development & hosting services
http://www.HostGIS.com/

"Remember that no one cares if you can back up,
  only if you can restore." - AMANDA