[mapserver-users] WFS support

[Daniel Morissette]

woodbri at swoodbridge.com wrote:
> 
> I noticed in the limitations for WFS Server that there are no plans
> for transaction support. I have not familiarized myself with the spec
> and I realize the that MapServer is not a GIS system that would be
> more suited to dealing with transactions, but I was wondering if a
> limited capability to add objects to a special layer or repository
> would not be a useful feature to Mapserver users. If this is well
> defined within the spec, I can imagine a site that would allow remote
> users the ability to add points, lines, etc to a write and view only
> repository on the server. These added objects could be added to a
> defined shapefile (yes, there are some locking issues that would need
> to be dealt with) or a PostGIS or MySQL database and the same could
> be defined as viewable layer(s).
> 

Hi Steve,

We should not forget that MapServer is a toolkit to serve maps and
navigation interfaces.  This is what it was designed and built for and
that's why it outperforms most (all?) other systems for fast webmapping
interfaces.  It is currently built and optimized for read-only access to
the data, so I'm not convinced that it would be a smart idea to start
bloating MapServer itself to support database updates.  My opinion may
change eventually, but for now I would be hesitant to go in that
direction.

However, this doesn't mean that you should be prevented from using WFS
transactions in a complete webmapping application.  Since MapServer is
just a toolkit, you could use it with another toolkit which would be
built and optimized for database and/or WFS transactions and then build
a complete webmapping site that combines fast navigation interfaces with
MapServer and WFS transactions with another tool.

This other tool could be a WFS built on top of OGR, or on top of
PostGIS, or any other data engine that MapServer supports already.  
So any update made to the data source using the WFS interface would be
reflected immediately on your MapServer map and the user would never
notice that you are actually using two tools to build your application.


BTW, I think we'll have a transactional WFS at some point in the not too
distant future.  If you can live with Java Servlets then there is
already Geoserver (http://geoserver.sourceforge.net/html/index.php)
which supports WFS.  I haven't tested it so I cannot tell you how well
it goes or if it supports transactions.  Other options also include
building a WFS interface on top of OGR directly (in C/C++), or on top of
PostGIS.

Daniel
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 Daniel Morissette               morissette at dmsolutions.ca
 DM Solutions Group              http://www.dmsolutions.ca/
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