[Mapserver-users] WMS: cascading GetFeatureInfo

[Bart van den Eijnden]

Hi list,

Mapserver does not cascade GetFeatureInfo requests and the reason for this 
is that the GetFeatureInfo response is not well-defined by the OGC.

This option is now limiting my application.

We have built a wrapper around ArcIMS which returns exactly the same 
msGMLOutput as Mapserver does. But with ArcIMS, every WMS server has a 
vendor-specific parameter called serviceName (e.g. cadastral, rivers, 
landuse etc.). Most of the time you have e.g. 10 services in ArcIMS, and 
all these are referenced by adding the serviceName vendor-specific 
parameter to the request.

For building a WMS which serves all the possible layers from my ArcIMS, I 
need to cascade them with Mapserver. But this way I can't get the 
GetFeatureInfo to work because Mapserver does not cascade GetFeatureInfo.

So basically I'm left with 2 options:
1) have all layers (from all services) in one WMS, but don't have 
GetFeatureInfo working
2) have GetFeatureInfo working but have 10 WMS servers.

I know cascading GetFeatureInfo would cause problems when using the 
layers=A,B,C syntax, but when just requesting one layer each time it would 
work by just sending the request to the remote WMS and sending back the 
response that this remote WMS sends. Ofcourse, you get into trouble when 
an application/user asks for layers=A,B and A and B are both of the WMS 
CONNECTIONTYPE and from a different brand of WMS.

Is there a way to just have Mapserver cascade GetFeatureInfo for the 
layers=A syntax and not for the layers=A,B,C syntax? Or even for the 
layers=A,B,C syntax when all layers are from the same WMS?

Any thoughts?

Best regards,
Bart