scale dependent getfeatureinfo

[Bart van den Eijnden (OSGIS)]

Hi Steven,

the GetCapabilities response will show you if a layer is queryable or not.
So as a WMS client you should not request GetFeatureInfo for layers which
are not queryable.

GROUP layers are not supported for GetFeatureInfo, GetLegendGraphic in
Mapserver because of the possiblity that they group heterogeneous/different
featuretypes.

Best regards,
Bart

--
Bart van den Eijnden
OSGIS, Open Source GIS
http://www.osgis.nl


--------- Oorspronkelijk bericht --------
Van: Steven M. Ottens <steven.ottens at GEODAN.NL>
Naar: MAPSERVER-USERS at LISTS.UMN.EDU <MAPSERVER-USERS at LISTS.UMN.EDU>
Onderwerp: Re: [UMN_MAPSERVER-USERS] scale dependent getfeatureinfo
Datum: 14/02/07 05:42

> On Feb 13, 2007, at 8:06 PM, Daniel Morissette wrote:
> 
> > Steven M. Ottens wrote:
> >> On Feb 13, 2007, at 3:25 PM, Stephen Woodbridge wrote:
> >>>
> >>> If you always get all 4 results, then only put the Query  
> >>> information in the most detailed layer and you will then
always  
> >>> get just that one. IE: remove it from the other layers.
> >>>
> >> Steve,
> >> I'm slightly at a loss here. What is the query information  
> >> exactly? I cannot remove the CLASSITEM from the other layers
since  
> >> they are raw grids which need to be classified. If I remove  
> >> TEMPLATE and the gml_* items from a  layer mapserver complains  
> >> that layers are not queryable.
> >
> > The GetFeatureInfo request contains a QUERY_LAYERS parameter with  
> > the list of layers to query. If you list all 4 layers in  
> > QUERY_LAYERS then MapServer returns results from each of them. If  
> > you want results from only the most detailed layer then list only  
> > that layer in QUERY_LAYERS.
> >
> Ok, but that means that the client needs to know which layer is the  
> preferred layer for getFeatureInfo. As far as I know, there's no  
> obvious way to automatically use the most detailed layer. The layer  
> can be added dynamically through a getCapabilities request, but there  
> are a few dozen others as well.
> Right now I have the group layer in the query_layers parameter, just  
> like I have it in the getMap parameter. In the getMap I get 1 image  
> back, the one which is suitable for that particular scale level. In  
> my opinion it would make sense if a similar behavior would be  
> possible for the getFeatureInfo.
> 
> Anyway since I do control the client I can hack it to check if the  
> particular layer for getFeatureInfo is indeed the elevation layer and  
> replace the group-name for the most detailed layer name.
> 
> Thanks for the help,
> 
> Steven
> 
>