[Mapserver-dev] OWS metadata and LegendURL clarification

[Julien-Samuel Lacroix]

Comment in-line.

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.

:) Thank to you for the feedback!

> 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?

I don't know if it was plan for the rest of the WMS/WFS code, but all 
those metadata are already available in the ows_*_* form. Also, the 
switch to support wms/wfs_* and ows_* in WMS/WFS code should be fairly 
easy I think. I will let Daniel comment.

> 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.
> 
> 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.

This was made like that for consistency with MapContext. In MapContext, 
we set wms_style_<style's_name>_legendurl_* because we can have more 
than one style. Do the WMS spec allow to have more than one style? If so 
we may want to support multiple styles and then this approach will make 
sense in WMS. But I also agree that it's a pretty big name for a 
metadata and that it reduce it's useability. Maybe we can support both 
format. use wms_style_blabla_... when we will have the wms_style 
metadata and use wms_legendurl_* when we won't have a style defined. 
However this may lead to confusion. What others think?

> ..Tom
> 

Thanks
Julien

-- 
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Julien-Samuel Lacroix            jlacroix at dmsolutions.ca
DM Solutions Group               http://www.dmsolutions.ca/
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