[OpenLayers-Dev] WMS: How can I have many layers on my map?

Kevin Emamirad keyone at gmail.com
Thu May 24 14:35:31 EDT 2007


Hi,

I've got two WMS layers on my world map: "countries" and "cities"

My openlayers application find by himself available layers by parsing
the XML result of the WMS's GetCapabilities request.
Available at http://localhost:8081/monde/wms?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetCapabilities

Here is how I add my layers:

/*************************/

var options = {maxResolution: 'auto', numZoomLevels: 20, format:
"image/png", VERSION: "1.3"};

var projet = "monde";

var url_app_wms = "../"+projet+"/wms";

var xml_getcapabilities =
"../"+projet+"/wms?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetCapabilities";

var map = new OpenLayers.Map('map');

for (j=2;j<x.length;j++)
{
    map.addLayers([new
OpenLayers.Layer.WMS(x[j].firstChild.nodeValue,url_app_wms,{layers:x[j].firstChild.nodeValue},options)]);
}

map.addControl(new OpenLayers.Control.LayerSwitcher());
map.zoomToMaxExtent();

/*************************/

This works well on OpenLayers. But when I choose "cities". I don't see
"countries" layout. So I have a map with cities points on a white
background.
I've also tried to use Overlays, with transparent = true argument. But
the only difference is that I have a black background.

But, when I'm doing the GetMap request by hand on my browser, this works.

http://localhost:8081/monde/wms?VERSION=1.3.0&REQUEST=GetMap&LAYERS=countries,cities&STYLES=&CRS=&BBOX=-75,43,-70,48&WIDTH=640&HEIGHT=480&FORMAT=image/png

with &LAYERS=countries,cities i've got both layers on my map.
with &LAYERS=countries , i've got only countries and i can also have
only cities with &LAYERS=cities


So what do you suggest me .

Thanks a lot,


Kevin Emamirad



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