[OpenLayers-Users] WFS reprojection on Google Maps

Thu May 5 12:13:01 EDT 2011

2011/5/5 Luís de Sousa <luis.a.de.sousa at gmail.com>:
> Thank you Andreas, it worked like a charm.
>
> There is one issue though, everytime I pan or zoom into the map I get
> this annoying "Map Data" dialogue about Google's copyright. Anyway to
> deal away with that?

If you're using OpenLayers 2.10, you have to replace

http://maps.google.com/maps/api/js?v=3.3&amp;sensor=false

with

http://maps.google.com/maps/api/js?v=3.2&amp;sensor=false

in the script resources.

Andreas.

>
> Thank you,
>
> Luís
>
> 2011/5/5 Andreas Hocevar <ahocevar at opengeo.org>:
>> Hey,
>>
>> OpenLayers.Layer.WFS is depracated. See
>> http://openlayers.org/dev/examples/wfs-protocol-transactions.html for
>> an example of how to overlay WFS layers properly on a Web Mercator
>> map.
>>
>> Note, however, that the main issue in your code is not the fact that
>> you are using OpenLayers.Layer.WFS (it seems like it is configured
>> properly), but missing map configuration parameters (units,
>> maxResolution, maxExtent). You either have to set them manually, or
>> use GMaps v3 instead of v2, because OpenLayers.Layer.Google v3 base
>> layers have these settings configured already. See
>> http://openlayers.org/dev/examples/google-v3.html for an example on
>> how to use v3.
>>
>> Also note that as soon as you work with Web Mercator maps, you cannot
>> specify coordinates in longitude/latitude. If you do so, you need to
>> transform them, which is also shown in the google-v3 example I linked
>> above.
>>
>> Regards,
>> Andreas.
>>
>> 2011/5/4 Luís de Sousa <luis.a.de.sousa at gmail.com>:
>>> Dear all,
>>>
>>> I've been trying to reproject WFS layers on Google Maps without
>>> success. After reading several threads here and elsewhere it became
>>> apparent that WFS 1.1.0 takes care of reprojections by itself, without any
>>> processing needed client side. Hence I tried simply to reproject the
>>> Tazmania shapes from Geoserver on a Google Maps base layer; while the
>>> WFS layers are indeed there, they do not seem to have been reprojected:
>>>
>>> http://www.flickr.com/photos/46630302@N04/5686739802/in/set-72157626519940667/
>>>
>>> Below goes the code, note that I'm using a local version of Geoserver
>>> on port 8090. I'd thank if anyone could hint at what I'm missing.
>>>
>>> Thanks,
>>>
>>> Luís
>>>
>>> -----
>>>
>>> <html xmlns="http://www.w3.org/1999/xhtml">
>>>   <head>
>>>       <style type="text/css">
>>>           #map {
>>>               width: 560px;
>>>               height: 460px;
>>>               border: 1px solid black;
>>>           }
>>>       </style>
>>>
>>>       <script src="http://localhost:8090/geoserver/www/OpenLayers-2.9/OpenLayers.js"
>>> type="text/javascript"></script>
>>>
>>>       <!-- Google API-->
>>>       <script src='http://maps.google.com/maps?file=api&amp;v=2&amp;key=ABQIAAAAjpkAC9ePGem0lIq5XcMiuhR_wWLPFku8Ix9i2SXYRVK3e45q1BQUd_beF8dtzKET_EteAjPdGDwqpQ'></script>
>>>
>>>       <script defer="defer" type="text/javascript">
>>>
>>>       function init(){
>>>
>>>           var map = new OpenLayers.Map("map", {
>>>               projection: new OpenLayers.Projection("EPSG:900913")
>>>           });
>>>
>>>           var gphy = new OpenLayers.Layer.Google(
>>>               "Google Physical",
>>>               {type: G_PHYSICAL_MAP}
>>>           );
>>>
>>>           var roads = new OpenLayers.Layer.WFS(
>>>               "Roads",
>>>               "http://localhost:8090/geoserver/wfs",
>>>               {typename: 'topp:tasmania_roads'},
>>>               {
>>>                   typename: 'tasmania_roads',
>>>                   featureNS: 'http://www.openplans.org/topp',
>>>                   extractAttributes: false,
>>>                   version: "1.1.0",
>>>                   srsName: "EPSG:900913"
>>>               }
>>>           );
>>>           roads.style = OpenLayers.Util.applyDefaults(
>>>               {strokeWidth: 2, strokeColor: "#ff0000"},
>>>               OpenLayers.Feature.Vector.style["default"]);
>>>
>>>           var states = new OpenLayers.Layer.WFS(
>>>               "States",
>>>               "http://localhost:8090/geoserver/wfs",
>>>               {typename: 'topp:tasmania_state_boundaries'},
>>>               {
>>>                   typename: 'tasmania_state_boundaries',
>>>                   featureNS: 'http://www.openplans.org/topp',
>>>                   extractAttributes: false,
>>>                   version: "1.1.0",
>>>                   srsName: "EPSG:900913"
>>>               }
>>>           );
>>>           states.style = OpenLayers.Util.applyDefaults(
>>>               {strokeWidth: 3, strokeColor: "#333333"},
>>>               OpenLayers.Feature.Vector.style["default"]);
>>>
>>>           map.addLayers([gphy, roads, states]);
>>>
>>>           map.addControl(new OpenLayers.Control.Navigation());
>>>           map.addControl(new OpenLayers.Control.LayerSwitcher());
>>>
>>>           map.setCenter(new OpenLayers.LonLat(147, -42), 7);
>>>
>>>       }
>>>       </script>
>>>
>>>   </head>
>>>   <body onload="init()">
>>>       <h5>This is a reprojection test on Google Maps.</h5>
>>>       <div id="map"> </div>
>>>   </body>
>>> </html>
>>> _______________________________________________
>>> Users mailing list
>>> Users at lists.osgeo.org
>>> http://lists.osgeo.org/mailman/listinfo/openlayers-users
>>>
>>
>>
>>
>> --
>> Andreas Hocevar
>> OpenGeo - http://opengeo.org/
>> Expert service straight from the developers.
>>
>

-- 
Andreas Hocevar
OpenGeo - http://opengeo.org/
Expert service straight from the developers.