[Mapserver-dev] OWS metadata and LegendURL clarification

[Yewondwossen Assefa]

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.



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/|
>>  -----------------------------------------------------------------
>>
>>
> 
> 
> _______________________________________________
> Mapserver-dev mailing list
> Mapserver-dev at lists.gis.umn.edu
> http://lists.gis.umn.edu/mailman/listinfo/mapserver-dev
> 


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Assefa Yewondwossen
Software Analyst

Email: assefa at dmsolutions.ca
http://www.dmsolutions.ca/

Phone: (613) 565-5056 (ext 14)
Fax:   (613) 565-0925
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