[OpenLayers-Users] OpenLayers.Format.WFS question/issue

[Stephen Woodbridge]

Bart and Christopher,

Thank you for your replies. I think it is probably working as expected. 
I need to find and read the spec and hopefully it will make some sense 
or at least some more sense.

I am currently trying to write a server in PHP that will work beside 
mapserver. So mapserver serves the features and the PHP handles the OL 
WFS-T responses.

Other than the fact that I am probably taking a naive approach to the 
parsing that will probably break if namespace prefixes change, it is 
working pretty well, except PHP4 has horrid XML parsing tools and I 
decided to rewrite the PHP code to be more compatible between PHP4 and 
PHP5 and deal with the bugfix that in the delete transaction namespace I 
reported.

Thank you both, your responses are educational and helpful.

Regards,
   -Steve W

Christopher Schmidt wrote:
> On Mon, Mar 10, 2008 at 11:38:46AM -0500, Stephen Woodbridge wrote:
>> Hi all,
>>
>> I admit up front that this inquiry might partly be my ignorance on the 
>> subject, but when OpenLayers.Format.WFS serializes a polygon insert 
>> request it looks like:
>>
>>   <wfs:Insert>
>>    <feature:Geofence xmlns:feature="http://mapserver.gis.umn.edu/mapserver">
>>     <feature:the_geom>
>>      <gml:MultiPolygon xmlns:gml="http://www.opengis.net/gml">
>>       <gml:polygonMember>
>>        <gml:Polygon>
>>         <gml:outerBoundaryIs>
>>          <gml:LinearRing>
>>           <gml:coordinates decimal="." cs="," ts=" 
>> ">-105.662109375,40.1591796875 -107.068359375,38.2255859375 
>> -103.640625,37.7861328125 -105.662109375,40.1591796875</gml:coordinates>
>>          </gml:LinearRing>
>>         </gml:outerBoundaryIs>
>>        </gml:Polygon>
>>       </gml:polygonMember>
>>      </gml:MultiPolygon>
>>     </feature:the_geom>
>>    </feature:Geofence>
>>   </wfs:Insert>
>>
>> This appears to be getting done by 
>> OpenLayers.Format.WFS.createFeatureXML(feature) and the namespace is 
>> hardcoded to "feature:..."
>>
>> My question is why this namespace and not the wfs namespace and XML 
>> something more like:
> 
> Can you provide some evidence that this is how it's supposed to be done?
> Inserts and Modifys are different in WFS-T: that's just a case of
> OpenLayerse following the spec, as far as I know?
> 
> Note that this isn't a case of the difference being the namespace: the
> difference here is that in Insert, you pass a full, GML-serialized
> feature. In Modify, you pass a specific property that you are
> modifying. 
> 
> Essentially, the WFS-T support is largely cobbled together from examples
> on the web. If you can provide examples of a server which I can post the
> following data to, and see a successful transaction, I'm interested. 
> 
>>   <wfs:Insert typeName="Geofence">
>>    <wfs:Property>
>>     <wfs:Name>the_geom</wfs:Name>
>>     <wfs:Value>
>>      <gml:MultiPolygon xmlns:gml="http://www.opengis.net/gml">
>>       <gml:polygonMember>
>>        <gml:Polygon>
>>         <gml:outerBoundaryIs>
>>          <gml:LinearRing>
>>           <gml:coordinates decimal="." cs="," ts=" 
>> ">-105.662109375,40.1591796875 -107.068359375,38.2255859375 
>> -103.640625,37.7861328125 -105.662109375,40.1591796875</gml:coordinates>
>>          </gml:LinearRing>
>>         </gml:outerBoundaryIs>
>>        </gml:Polygon>
>>       </gml:polygonMember>
>>      </gml:MultiPolygon>
>>      </wfs:Value>
>>    </wfs:Property>
>>    <wfs:Property>
>>     <wfs:Name>name</wfs:Name>
>>     <wfs:Value>noname</wfs:Value>
>>    </wfs:Property>
>>   </wfs:Insert>
>>
>> This would more closely follow the <wfs:Modify> format and namespace.
> 
> WFS-T support was built on examples, primarily from GeoServer, with
> support from Cameron Shorter and others who wrote the original vector
> code. The XSDs shipped with the spec are totally useless to me, even
> when they're actually accurate, so I don't have a good backup of why it
> was done this way, other than "I thought it should be done this way.
> 
>> So why should anyone care? mostly the later is much easier to parse as 
>> the tags are predetermined by the wfs namespace and not consturcted from 
>> the arbitrary attributes used in the layer definition.
> 
> 'arbitrary attributes'? The Layer Definition ('Schema') For a WFS layer
> is key to all work with WFS, no?
> 
>> I am interested in the "why of this" so I better understand how all this 
>> works. Reading the code, it looks like this change can be done by 
>> overloading createFeatureXML with code that generates the later XML 
>> above, so I could make the change myself outside of the OL code base for 
>> testing and review.
>>
>> If I did that would it be an appropriate change to svn?
>> A change to svn, would probably break any existing services that depend 
>> on the existing format for <wfs:Insert>.
> 
> What does the spec say? This matters more than 'existing services', as
> far as I'm concerned, but the existing insert statements work with
> GeoServer, Manifold, and at least some others, and GeoServer is what I was
> working with when I wrote it.
> 
> Regards,