[mapserver-dev] testing CLUSTER object

[Jeff McKenna]

Hello all,

Just doing some tests for the docs, and I have the following 
comments/feedback/questions regarding the new CLUSTER object in 
MapServer 6.0:

- why isn't the LAYER TYPE ANNOTATION supported for the cluster object? 
  A common trick for labelling symbols is to use an annotation layer, I 
really think the cluster logic should be applied to that type as well.

- I think there is a problem with query results from a cluster.  If I 
query a non-cluster-object group of features with mode=nquery (and a 
template set at the LAYER level) I get the correct number of features 
returned; If I query the same cluster-object group of features with 
mode=nquery (and a template set at the LAYER level) I only ever get one 
feature result (testing with MapServer trunk).  Thoughts?

- If you look at my example layer 
(http://www.mapserver.org/trunk/mapfile/cluster.html#example-clustering-railway-stations), 
you can see that I had to do some tricks with an expression to not show 
a cluster object for when the featurecount = 1; should this be the case? 
  Would anyone using MapServer ever need a cluster for one feature?

- I've had "challenges" trying to stop the cluster circle symbols from 
being split at tile edges with mod-geocache 
(http://labs.gatewaygeomatics.com/cluster/demo.html) Yes it could be a 
missing setting either in my mapfile or in my geocache.xml, but I still 
want to report this.  Maybe this is a good sign that we (MapServer or 
mod-geocache) need to make it easier for new users to prevent this from 
occurring?

Thanks for listening :)

-jeff



-- 
Jeff McKenna
MapServer Consulting and Training Services
http://www.gatewaygeomatics.com/