associating WFS or WCS to WMS services - how-to?

[Bart van den Eijnden]

Hi Jeroen,

isn't the WMS DescribeLayer request purposed just for this? It isn't directly accessed through WMS Capabilities but a separate request to the WMS service.

Mapserver WMS can return the WFS (vector) or WCS (raster) associated with the WMS layer as a DescribeLayer response.

Best regards,
Bart

Bart van den Eijnden
Syncera IT Solutions
Postbus 270
2600 AG  DELFT

tel.nr.: 015-7512436
email: BEN at Syncera-ITSolutions.nl
>>> Jeroen Ticheler <JEROEN.TICHELER at FAO.ORG> 11/09/05 1:19 PM >>>
Hi!
We are trying to find the (most suitable) way of associating a WFS or  
a WCS to an existing WMS service. The purpose of this is that we can  
use WMS to display the interactive maps while we use the WFS/WCS to  
extract data from the server and make it available to the user as  
GML, shapefile, GeoTIFF etc... to be downloaded from an FTP or  
directly for local use.

The problems we have are two-fold:
1- What is the best location in a Capabilities document to do this?  
We want our client application to know of the existence of the WFS or  
WCS service.
	What we think as best candidates are:

	- the DataURL element

(definition: A server may use DataURL to offer a link to the  
underlying data represented by a particular layer. The
enclosed Format element indicates the file format MIME type of the  
data file.)

	- or the FeatureListURL element

(definition: A server may use a <FeatureListURL> element to point to  
a list of the features represented in a Layer.
FeatureListURL is not inherited by child layers. The enclosed Format  
element indicates the file format MIME
type of the feature list.)

2- If we use one of these, we think of putting in the link to the  
service and a suitable MIME type. We have seen the following MIME  
types used for WMS and WFS getCapabilities requests, but are not sure  
they are standard and also we didn't find any reference to a similar  
WCS MIME type. What to do???
	
We found:

	application/vnd.ogc.wms_xml

and

	application/vnd.ogc.wfs_xml

	- Should we use these MIME types to indicate the URL points to a WMS  
or WFS getCapabilities?
	- Should we assume we can use 	application/vnd.ogc.wcs_xml	for a WCS  
getCapabilities MIME type!?

We have not found any of the application/vnd.ogc MIME type registered  
at http://www.iana.org/assignments/media-types/  What should be our  
conclusion on that?

Thanks in advance!
Ciao,
Jeroen & Stefano