[Mapserver-dev] OWS metadata and LegendURL clarification

Fri Oct 29 10:41:44 EDT 2004

> -----Original Message-----
> From: Yewondwossen Assefa [mailto:assefa at dmsolutions.ca] 
> Sent: Friday, 29 October, 2004 10:34
> To: Kralidis,Tom [Burlington]
> Cc: pspencer at dmsolutions.ca; mapserver-dev at lists.gis.umn.edu
> Subject: Re: [Mapserver-dev] OWS metadata and LegendURL clarification
> 
> 
> We could also decide that if the wms_style_* is not defined 
> in the map 
> file, we could still generate a LegendURL (pointing to a 
> GetLegendgGraphic with defeault width and heigh taken from the legend 
> element if available ). This syle returned would be "default" as 
> suggested in bug 1001.
> The only think that I do not like is that we are telling the 
> user that a 
> style named default is available which is not really true. If 
> we do that 
> we should also support request with STYLE=default to be compatible.
> 
> One last thing, I think we shoudl either continue this in bug 1001 or 
> open a new one.
> 

The comment #4 of bug 1001 discussed the LegendURL issue.

http://mapserver.gis.umn.edu/bugs/show_bug.cgi?id=1001#c4

> 
> 
> Kralidis,Tom [Burlington] wrote:
> 
> >>-----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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> > Mapserver-dev at lists.gis.umn.edu 
> > http://lists.gis.umn.edu/mailman/listinfo/mapserver-dev
> > 
> 
> 
> -- 
> ----------------------------------------------------------------
> Assefa Yewondwossen
> Software Analyst
> 
> Email: assefa at dmsolutions.ca
> http://www.dmsolutions.ca/
> 
> Phone: (613) 565-5056 (ext 14)
> Fax:   (613) 565-0925
> ----------------------------------------------------------------
> 
> 
> 