[Chameleon] Extract from WFS

Bart van den Eijnden BEN at Syncera-ITSolutions.NL
Thu Jun 30 11:54:41 EDT 2005


this is difficult stuff to grasp actually.

The ExtractWFS widget uses the WFS GetFeature interface to get its data. It can then output in the form of GML (or shapefile if you have the php_ogr extension).

So if you have a CONNECTIONTYPE WMS layer in your Chameleon MAP file, Chameleon will see if the WMS layer is associated with a WFS interface using a WMS DescribeLayer request. If you have a CONNECTIONTYPE WFS layer in your Chameleon app MAP file, it will directly request a GetFeature for the appropriate bounding box.

This does not work with LOCAL layers, only for CONNECTIONTYPE WMS and CONNECTIONTYPE WFS layers.

The world_wms.map file which comes with the Chameleon samples uses the DM Solutions server, so the DM Solutions MAP file is setup to have a WFS interface and contains all the wfs_ metadata stuff.

Hope this helps.

Best regards,

Bart van den Eijnden
Syncera IT Solutions
Postbus 270
2600 AG  DELFT

tel.nr.: 015-7512436
email: BEN at Syncera-ITSolutions.nl

>>> "Gail" <Gail.Millin at manchester.ac.uk> 06/30/05 05:45pm >>>
Hi List,


I would like to use the 'Extract from WFS' widget but I am rather confused
on how it actually works. Is there any reading material you could point me
to specific for Chameleon? Do I need to create a WFS mapfile? From the
material I have read on the MapServer website (WFS Client HOWTO and WFS
Server HOWTO) it would appear that I need to, as it says to define the
metadata parameters with wfs_ prefix. However I was looking at the OGC
viewer on the Chameleon Samples list which contains the Extract from WFS
widget and was trying to figure out how that viewer works. When I did a
search in the chameleon directory I could only find 2 .map files and these
are for WMS there is no indication of any wcs.map file in the directory. 


I am abit confused on how the WFS integrates into the Chameleon viewer, any
suggestions or guidance I would appreciate.


Kind Regards




Gail Rebecca Millin
Geodata Interoperability Support Officer
Manchester Computing
The University of Manchester
Oxford Road
M13 9PL


Telephone: +44 (0) 161 275 0581

E-mail: Gail.Millin at manchester.ac.uk 
Website: http://www.mimas.ac.uk/spatial 


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