[Qgis-developer] Re: [Qgis-user] QGIS mapserver project
Marco Hugentobler
marco.hugentobler at karto.baug.ethz.ch
Mon May 14 02:52:47 EDT 2007
Hi Martin,
> Btw. is it necessary to link also to gui library?
You're right, it works only with core. I had the link to gui in the makefile
from the 0.8 time on and didn't realize it is not needed anymore.
> > QGIS mapserver doesn't (yet) have the same number of features as the
> > maperservers which are around for many years. But it is already usable as
> > a basic WMS server with SLD styling capabilities. It already supports
> > GetCapabilities and GetMap over HTTP GET and allows client defined
> > styling with SLD.
>
> How would you compare SLD with QGIS display capabilities? Is SLD a
> subset or superset of what can be displayed with QGIS libs? I'm
> wondering whether SLD could be useful also for saving layer's
> symbology...
The SLD specifications contain more than QGIS provides. But for me it seems
that the idea was to cover everything and so most existing software only
supports a subset of SLD (e.g. for UMN mapserver, see
http://mapserver.gis.umn.edu/docs/howto/sldhowto/#server-side-support).
Some examples what SLD containes and QGIS does not provide:
Complex filters possible for categories, combinations of spatial filters,
and/or, equals, greater, lesser, greater or equal, lesser or equal, between,
like
lines: graphic fill, custom fill/gap
polygons: graphic fill (repeated texture)
point: the URL of any graphic file can be given as symbol
And there are also raster and label contained in SLD spec...
For qgis internal purposes, I think it would be easier to use the qgis xml
format. But for exchange of symbologies with other applications, SLD would be
better.
Some time ago, I started to write a plugin which generates an SLD
configuration file for the server from loaded QGIS layers. But maybe
import/export from/to SLD would also be interesting for QGIS gui?
> At some point in future I should deploy a web application with mapping
> support, so I'll take a look if this mapserver is usable enough. It's
> a pity that QGIS doesn't support advanced symbology and the labeling
> is still very inmature - these features are quite important for a good
> mapserver.
Yes, lots of work to be done :-)
What do you think are the most important missing symbology capabilities?
cheers,
Marco
--
Dr. Marco Hugentobler
Institute of Cartography
ETH Zurich
marco.hugentobler at karto.baug.ethz.ch
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