[mapserver-users] LABEL-formatting options

[pcreso at pcreso.com]

Yep, always frustrating to suffer such constraints.

Can you not define the layer in mapserver as an ogr layer rather than a native shapefile, and use ogr's pseudo-sql to cast/retrieve the value as a numeric more suitable for labeling with?

http://www.gdal.org/ogr/ogr_sql.html

Then in your mapfile use connectiontype ogr, as in:
http://mapserver.org/input/vector/ogr.html 

(see example 4 with shapefiles joined in an ogr query)

I agree it would be nice to have mapserver able to do this, but until then there should be some workaround (like this) that will suffice.

Cheers,

 Brent


--- On Wed, 3/10/10, Stephan Holl <stephan.holl at intevation.de> wrote:

> From: Stephan Holl <stephan.holl at intevation.de>
> Subject: Re: [mapserver-users] LABEL-formatting options
> To: pcreso at pcreso.com
> Cc: mapserver-users at lists.osgeo.org
> Date: Wednesday, March 10, 2010, 9:09 PM
> Hello Brent,
> 
> pcreso at pcreso.com,
> [20100309 - 23:49:56]
> 
> > Hi Stephan,
> > 
> > Can you not add an appropriate column automatically as
> the shapefile
> > is generated?
> > 
> > Tools such as dbfscript (http://www.whitetown.com/dbf-script/) or
> > perhaps script something with the shapelib libraries
> or tools or the
> > ogr tools?
> 
> Yes, it is possible. 
> 
> But: I think it is a feature which mapserver should deal
> with.
> 
> > 
> > I have found that using Postgis rather than shapefiles
> gives you the
> > ability to easily manage such issues as the data
> retrieved by
> > mapserver is derived from an SQL query which allows
> the creation of
> > virtual "columns" for labels on the fly.
> 
> In our case we do not have a chance to use any DB at all,
> since the
> infrastructure permits it. The data are retrieved from
> caclculations,
> which are itself done on a (remote) server.
> 
> > 
> > Treating this sort of problem as a data management
> problem, in terms
> > of supplying the desired data derived on the fly from
> the stored
> > data, allows a tool such a Postgis to do what a
> database is designed
> > for. A script using shp2pgsql or ogr2ogr to
> automatically turn your
> > shapefile into a Postgis table, and render this using
> mapserver
> > instead of the shapefile should fix your problem.
> 
> As said, the specific infrastructure (sadly) does not allow
> to use
> PostGIS and the like (yet).... 
> I am after a more general approach (in
> order to make MapServer a little better), for my usecase it
> is easy to
> add a 'display'-column with the right decimal values
> trimmed.
> 
> Cheers
>     
>     Stephan
> 
> > > On Behalf Of Stephan Holl [stephan.holl at intevation.de]
> > > Sent: Tuesday, March 09, 2010 7:54 AM
> > > To: mapserver-users at lists.osgeo.org
> > > Subject: [mapserver-users] LABEL-formatting
> options
> > > 
> > > Hello mapservers,
> > > 
> > > we are using MapServer for visualizing shapefiles
> with
> > > double entries
> > > inside.
> > > 
> > > Mainly this are contour-lines from waterdepth.
> The double
> > > values have
> > > 32 decimal places and mapserver tries to render
> them _all_
> > > along a
> > > contourline.
> > > This does not look nice...
> > > 
> > > Is there an option to trim the values with a
> dedicated
> > > mapfile-parameter, e.g. where a prinft-syntax can
> be used
> > > to format the
> > > values?
> > > 
> > > The shapefiles are generated automatically so
> adding
> > > another column with
> > > trunc()ed or round()ed values is no option.
> > > 
> > > Are there any options to format
> label-values/strings? I
> > > have not found
> > > anything in the docs.
> > > 
> > > TIA
> > > 
> > >         Stephan
> > > 
> > > --
> > > Stephan Holl <stephan.holl at intevation.de>
> > > | Tel.: +49 (0)541-33 508 3663
> > > Intevation GmbH, Neuer Graben 17, 49074 OS  | 
> AG
> > > Osnabrück - HR B 18998
> > > Geschäftsführer:  Frank Koormann, Bernhard
> Reiter,
> > > Dr. Jan-Oliver Wagner
> > > _______________________________________________
> > > mapserver-users mailing list
> > > mapserver-users at lists.osgeo.org
> > > http://lists.osgeo.org/mailman/listinfo/mapserver-users
> > > 
> 
> 
> -- 
> Stephan Holl <stephan.holl at intevation.de>
> | Tel.: +49 (0)541-33 508 3663
> Intevation GmbH, Neuer Graben 17, 49074 OS  |  AG
> Osnabrück - HR B 18998
> Geschäftsführer:  Frank Koormann, Bernhard Reiter,
> Dr. Jan-Oliver Wagner
>