[Mapserver-dev] OWS metadata and LegendURL clarification

[Kralidis,Tom [Burlington]]

> -----Original Message-----
> From: Paul Spencer [mailto:pagameba at magma.ca] 
> Sent: Friday, 29 October, 2004 10:12
> To: Kralidis,Tom [Burlington]
> Cc: mapserver-dev at lists.gis.umn.edu
> Subject: Re: [Mapserver-dev] OWS metadata and LegendURL clarification
> 
> 
> Tom ... comment below ...
> 
> Kralidis,Tom [Burlington] wrote:
> > Hi,
> > 
> > First off, I'd like to thank Julien and Assefa for their work in 
> > implementing msOWSPrintURLType() (bug 944)into CVS and 
> LegendURL (bug 
> > 1001).  This will enable richer output for OGC metadata in 
> > Capabilities, as well as streamlining the way URLs are formatted.  
> > This will be a big benefit for the catalogs and registries 
> out there 
> > who harvest OGC Web Services for discovery.
> > 
> > As a result, mapfiles can now define:
> > 
> > "wms_dataurl_format"
> > "wms_dataurl_type"
> > "wms_dataurl_href"
> > 
> > "wms_metadataurl_format"
> > "wms_metadataurl_type"
> > "wms_metadataurl_href"
> > 
> > "wfs_metadataurl_format"
> > "wfs_metadataurl_type"
> > "wfs_metadataurl_href"
> > 
> > Question:
> > 
> > will the generic ows_* directives be implemented for WMS 
> and WFS, as 
> > they were for WCS, in time for 4.4.0?
> > 
> > For Legends (bug 262, which was solved by bug 944):
> > 
> > wms_style    =>  name of the style
> > wms_style_<style's_name>_legendurl_href
> > wms_style_<style's_name>_legendurl_format
> > wms_style_<style's_name>_legendurl_width
> > wms_style_<style's_name>_legendurl_height
> > 
> > Question:
> > 
> > The issue I have with this is that someone has to explicitly define 
> > this in the mapfile.  AFAIK, MapServer doesn't support 
> multiple styles 
> > in WMS for layers, so we always default to one style.
> 
> this is implemented to support *other* wms servers that do support 
> multiple styles.  When parsing contexts or capabilities, we 
> need a place 
> to store the styles supported by the remote server and this was the 
> mechanism chosen to do this.  This allows mapscript applications to 
> present a choice of styles to the user and to allow them to change 
> between styles.  MapServer (as a WMS client) will append the 
> appropriate 
> STYLE= to GetMap requests ... the other information is there to allow 
> mapscript applications to generate some sort of reasonable legend 
> graphic if possible since legends are not supported through the WMS 
> server yet (at least not directly).
> 
> > 
> > IMHO, the only directives a user should be able to configure are:
> > 
> > "wms_legendurl_href"
> > "wms_legendurl_width"
> > "wms_legendurl_height"
> > 
> > (note the change to "wms_legendurl_*" from
> > "wms_style_<style's_name>_legendurl_*)
> > 
> > If and only if they define a static image for the href.  
> Else, if they 
> > don't define anything a LegendURL should be returned in 
> Capabilities.
> > 
> > This is partly addressed in bug 1001.
> > 
> > Comments?  I hope this made sense.
> 
> I think your suggestion would break all my code :>
>

I see your point from the client side of things.  However, from the WMS
Server side, I see this could be a potential burden i.e. creating
'wms_style*' info when all this could be generated on the fly by the
server (i.e. with GetLegendGraphic and default styles).



 
> > 
> > ..Tom
> > 
> > _______________________________________________
> > Mapserver-dev mailing list
> > Mapserver-dev at lists.gis.umn.edu 
> > http://lists.gis.umn.edu/mailman/listinfo/mapserver-dev
> > 
> 
> -- 
>   -----------------------------------------------------------------
> |Paul Spencer                           pspencer at dmsolutions.ca   |
> |-----------------------------------------------------------------|
> |Applications & Software Development                              |
> |DM Solutions Group Inc                 http://www.dmsolutions.ca/|
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