[Mapserver-dev] MapServer and OGC services

[Paul Spencer]

Daniel,

regarding whether or not to use ows_* in the metadata, I think it really 
depends on whether a title, abstract, etc needs to be different 
depending on how the mapfile is accessed.  I personally think that this 
metadata should have the same meaning to all services acessing it.  I 
agree that it may be desirable to override the behaviour with a 
service-specific prefix.  In general, however, using "title" will be a 
lot more meaningful that "wms_title" and "wfs_title" or even 
"ows_title".  WRT SRS, can the SRS be published at the map file level also?

A final suggestion for even more configurability/control/complexity, 
although I am not keen on it.  Allow the user of the mapfile to 
determine which metadata is published as what by providing a mechanism 
through the web metadata object:
MAP
   WEB
     METADATA
       "wms_layer_title" "title"
       "wfs_layer_title" "title2"
     END
   END
   LAYER
     METADATA
       "title" "this is the wms title"
       "title2" "this is the wfs title"
     END
   END
END

this would have to have a default behaviour of always using a particular 
metadata item for wms_title and wfs_title (say, "title" ;)) if not 
specified.

Daniel Morissette wrote:

> Tom,
> 
> I would tend to agree with you on the fact that there is an issue there,
> but unfortunately I don't think the solution is simple.  When I
> implemented the WFS it really bugged me to have to create duplicate
> metadata names for things like wms_title and wfs_title, and I thought
> about coming up with something more generic such as ows_title (OGC Web
> Service Title), etc.  Perhaps I should have done it, but I wasn't
> convinced that this was good enough to justify breaking with the past so
> I just ended up going the easy route and went with wfs_* metadata names.
> 
> Note that in some cases someone might want to use different values for
> some parameters depending on server types.  This may not be very common
> for layer names and titles, but for instance the SRS don't work the same
> way in WMS and WFS, so someone might want to set different values for
> wms_srs and wfs_srs.
> 
> Perhaps the best would be to allow a combination of both, i.e. if you
> set "ows_title" then that applies to any OGC web service, but you have
> the option to set server-specific values using the service name as
> prefix, e.g. "wms_title" or "wfs_title" in this case.
> 
> So to reuse your example, you could have:
> 
>  LAYER
>   NAME roads
>   METADATA
>    "ows_title" "road network"
>    "wms_abstract" "Abstract that applies to WMS only"
>    "wfs_abstract" "Abstract that applies to WFS only"
>   END
>  ...
>  END
> 
> 
> What do you (and others) think?
> 
> Another question: do we need the "ows_" prefix or not for the generic
> metadata value?  It may be nice to have to indicate that this metadata
> applies to OGC web services, but OTOH we may end up with the same
> problem later on when we decide to support other uses for this
> metadata.  I'm really not sure what's best.
> 
> Daniel
> 
> 
> 
> Tom.Kralidis at ccrs.nrcan.gc.ca wrote:
> 
>>Hi,
>>
>>I'd like to provide a few comments w.r.t. MapServer current and forthcoming
>>support of OGC services, and development of them.  This comes after I set up
>>a WMS with MapServer, and was looking to set up WFS as well.
>>
>>Currently, MapServer provides WMS publishing by means of directives through
>>the mapfile, whose structure is basically "wms_<parameter>" "value".
>>Populating these fields produces the appropriate information to respond to
>>an OGC WMS GetCapabilities request.
>>
>>According to the following wiki:
>>
>>http://mapserver.gis.umn.edu/cgi-bin/wiki.pl?WFSMapServer
>>
>>..one can have WFS functionality also by using a similar nomenclature, i.e.
>>"wfs_<parameter>" "value", in various areas of a mapfile.
>>
>>Having said this, I find myself adding directives with the same information
>>in order to publish as WMS and WFS, i.e.
>>
>>LAYER
>> NAME roads
>> METADATA
>>  "wms_title" "road network"
>>  "wfs_title" "road network"
>> END
>>...
>>END
>>
>>While this may not be a huge deal, given the limited OGC services supported
>>by MapServer, what happens when MapServer supports other OGC services,
>>current and / or forthcoming?
>>
>>Perhaps an abstracted model and approach should be put forth in the mapfile?
>>i.e.
>>
>>LAYER
>> NAME roads
>> METADATA
>>  TITLE "road network"
>>  ABSTRACT "This is a road network"
>>  ...
>> END
>>...
>>END
>>
>>This would streamline the approach for those populating mapfiles; also the
>>software can fork out the information, depending on the type of request it
>>gets (i.e. services=wms|wfs|...).  I guess what I'm saying is that thought
>>should be given to MapServer working with this information independently,
>>and not having to add parameters according to specs, yet publish information
>>as per the spec using the internal model of the mapfiles.
>>
>>Comments?
>>
>>..Tom
>>
>>=================================
>>Tom Kralidis
>>Systems Scientist
>>Canada Centre for Remote Sensing
>>Tel: (613) 947-1828
>>http://www.cgdi.ca/
>>=================================
> 
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-- 
Paul Spencer
Applications and Software Development
DM Solutions Group Inc.
http://www.dmsolutions.ca