[OpenLayers-Users] Openlayers and Mapserver

Mon Oct 24 18:30:53 EDT 2011

Hi List,

I'm trying to use OpenLayers and Mapserver as a WFS. I'm having some
difficulty understanding how to deal with projections within the browser and
on the server-side. Within OpenLayers I have the following html:

<html>
<head>
    <title>OpenLayers Example</title>
    <script src="http://openlayers.org/api/OpenLayers.js"></script>
    <script type="text/javascript" src="
http://maps.googleapis.com/maps/api/js?sensor=false"></script>
 </head>
 <body>
      <div style="width:100%; height:100%" id="map"></div>
      <script type="text/javascript">

        mapOptions = {
            projection: new OpenLayers.Projection("EPSG:3857"),
            units: "m",
           maxExtent: new OpenLayers.Bounds(-715222.69, 6422313.80,
196915.72, 7521021.46)
    };

    map = new OpenLayers.Map('map', mapOptions);

    var googleLayer = new OpenLayers.Layer.Google('Google', {type:
google.maps.MapTypeId.SATELLITE}, {"sphericalMercator": true});
    map.addLayer(googleLayer);

    // Add WFS data
    var wfsLayer= new OpenLayers.Layer.Vector("WFS", {
         strategies: [new OpenLayers.Strategy.BBOX()],
         protocol: new OpenLayers.Protocol.WFS({
           url: "http://mysite.com/mapserv.cgi/wfs?&map=wfs_mlsoa.map&",
           featureType: "mlsoa",
           featureNS: "http://mapserver.gis.umn.edu/mapserver",
           srsName: "EPSG:3857",
           version: "1.1.0",
           geometryName: "NAME"
       })
   });

   //add layers
   map.addLayers([googleLayer,wfsLayer]);

</script>
</body>
</html>

And on my mapserver side I state that my map/data has the following
projection:

  PROJECTION
    "init=epsg:3857"
  END

and extents

EXTENT  -715222.69 6422313.80 196915.72 7521021.46

I am assuming that it is ok to use the epsg:3857 code (the equivalent of
epsg:900913) with data projected using ESRI's 'Mercator_Auxilary_Sphere'.
However, I cannot get my bbox to retrieve the data. The shapefile is an
outline of England. When I view the post/get using Firebug I see that the
response is:

<gml:boundedBy>
<gml:null>unknown</gml:null>
</gml:boundedBy>

I saw that this question about changing projections
http://osgeo-org.1803224.n2.nabble.com/wfs-openlayers-non-native-projection-td6146097.htmlwhich
is why I tried to overwrite the default options. I'm not sure what
else to try and would appreciate any suggestions.

Thank you,
David
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