[Context.RWG] Using OWS Context to describe GML/WFS layers whichdecimate

[Kralidis,Tom [Burlington]]

> -----Original Message-----
> From: Cameron Shorter [mailto:cameron.shorter at gmail.com] 
> Sent: 31 October, 2006 7:17 PM
> To: Kralidis,Tom [Burlington]
> Cc: Martin Daly; context.rwg at opengeospatial.org; 
> webmap-discuss at mail.osgeo.org; Raj Singh
> Subject: Re: [Context.RWG] Using OWS Context to describe 
> GML/WFS layers whichdecimate
> 
> Kralidis,Tom [Burlington] wrote:
> > Cameron,
> > 
> > So you want one OWSContext FeatureType to hold many GML documents?
> > 
> > If yes, can you not define each GML doc as an OWSContext 
> FeatureType, 
> > each with respective scale rules?
> 
> Tom,
> Using Style scale rules to make a layer visible or not would 
> be one solution - but with a number of limitations:
> 1. If I were to build a LayerList (or Legend) from the 
> Context, would I end up with a layer for each scale?
> 

Yes, however you could build your client Legend handler to show layers
only if they're within the scale range of where the application scale is
at.

> 2. If my legend was smart, and layers were only visible at 
> certain resolutions, how do I associate a HighResolutionLayer 
> with a LowResolutionLayer so that the Layer attributes (like 
> visibility) can be associated between layers.
> 

If OWSContext identified the notion of a @group attribute as part of the
AbstractResourceType, this might be an option.  There has been some mild
discussion on this front.


> 
> >  
> > 
> > 
> >>-----Original Message-----
> >>From: Cameron Shorter [mailto:cameron.shorter at gmail.com]
> >>Sent: 30 October, 2006 7:29 PM
> >>To: Martin Daly
> >>Cc: context.rwg at opengeospatial.org; Kralidis,Tom [Burlington]; 
> >>webmap-discuss at mail.osgeo.org; Raj Singh
> >>Subject: Re: [Context.RWG] Using OWS Context to describe GML/WFS 
> >>layers whichdecimate
> >>
> >>Martin,
> >>Point taken regarding G/Y/M maps. Replace zoomLevel with 
> >>sld:Min/MaxScaleDenominator in my previous comment.
> >>
> >>I still need to reference different GML sources for each layer 
> >>depending on scale, which doesn't seem to be covered by OWS Context 
> >>yet.
> >>
> >>
> >>Martin Daly wrote:
> >>
> >>>>zoomLevel is a term used by Google/Yahoo/MSN Maps.
> >>>>It is a measure of resolution. As you zoom out, the zoomLevel 
> >>>>increases.
> >>>
> >>>
> >>>That is not a definition that will wash in a standard that 
> aims for 
> >>>interoperability.
> >>>
> >>>In fact, OWS Context already uses 
> sld:Min/MaxScaleDenominator in the 
> >>>AbstractResourceType, so the capability already exists.
> >>>
> >>>As with the previous long e-mail trail re. GYM data, this
> >>
> >>spec. should
> >>
> >>>leverage de jure OGC standards, not de facto ones that
> >>
> >>large parts of
> >>
> >>>the target audience cannot use.
> >>>
> >>>M
> >>>
> >>>
> >>
> >>
> >>--
> >>Cameron Shorter
> >>http://cameron.shorter.net
> >>
> > 
> > 
> 
> 
> --
> Cameron Shorter
> http://cameron.shorter.net
>