Hi Etienne, there is no specific reason I guess, but WMS is intended for visualisation, so it mostly ends there. That's why they invented a DescribeLayer request in the SLD WMS spec to get more detailed info of the data underneath the WMS (linkage to another OGC interface).
Your basic route should be: -WMS DescribeLayer -WFS DescribeFeatureType But this means the data should be available on both a WMS and a WFS. Best regards, Bart Bart van den Eijnden Syncera IT Solutions Postbus 270 2600 AG DELFT tel.nr.: 015-7512436 email: [EMAIL PROTECTED] >>> Etienne Labuschagne <[EMAIL PROTECTED]> 25-10-2005 12:10 >>> Bart, Thanks for the prompt reply, even though this is exactly what I didn't want to hear ;) Am I missing something or is this just plain silly? I come from an ESRI ArcIMS environment and I expected that getting the layer's geometry type should be one of the basic easy things to do. I understand that some implementations does give this info, but surely this should be part of the basic OGC standard? Maybe there is a good reason that this is not included and would love to hear it! Anyway, thanks for the trouble. Etienne On Tue, 2005-10-25 at 11:22 +0200, Bart van den Eijnden wrote: > Hi, > > it depends with the implementation, but it is a difficult theory anyway > already :-) > > WMS can be coupled to a WFS (on the same data) using a DescribeLayer WMS > request. This is part of the SLD WMS spec. > The response of a WMS DescribeLayer is: > > a) the onlineresource of a WFS (or WCS for raster layers) > b) the name of the typename > > With this info, you could request more info from the associated WFS, mostly > WFS DescribeFeatureType will be useful for that. It will give you all the > attributes and most likely (depending on the implementation) also an idea of > the geometry type. Note that something was changed in Mapserver 4.6 which > makes it ouput a gml abstract featuretype by default, which won't give you an > idea of the geometry type. > > Note also that WMS GetFeatureInfo could give you a rough guess of the > geometry type, and the list of attributes in the GML returned. But it is > specific to a point clicked in the map. Mapserver also gives back a geometry > on the WMS GetFeatureInfo (which you could check for point, polygon or line > in the string), but most WMS's don't give back the geometry on WMS > GetFeatureInfo. > > Anyway, you can see it's not straightforward. > > Best regards, > Bart > > Bart van den Eijnden > Syncera IT Solutions > Postbus 270 > 2600 AG DELFT > > tel.nr.: 015-7512436 > email: [EMAIL PROTECTED] > > >>> Etienne Labuschagne <[EMAIL PROTECTED]> 25-10-2005 10:13 >>> > Hi all, > > I'm a newbie to MapServer and OGC in general. > > I can discover the layer names with a WMS getCapabilities call. The other > thing I need to discover is what type each layer is (Point, line, polygon) > and also what attribute fields there are available on each layer. > > Is there an OGC way to get this information from any OGC compliant map > server? The reason I say "OGC" is that my client program that I am writing > need to adhere to that standard and not nescessarily only MapServer. > > Although I use MapServer predominantly, I may have to use other map servers > later and do not want to be bound by MapServer proprietary code. > > Thanks > Etienne >
