[OpenLayers-Users] Display WMS over OSM with OL

Wed Oct 17 12:19:23 PDT 2012

Good morning,

I´m writing this mail because i need some help with OL, and i couldn´t find any solution on the web.
I work in a map overlaping a wms point layer over OSM and this only displays the overlay when map is in max_extent but when i use zoom in twice the overlay dissapears, this overlay have get_feature option active and it loads the info when a click over any wms point but i cant see any point indeed.
I guess it isn' t a projection problem because the wms attributes are loaded when click in any point even if i can´t see any of them. The wms have EPSG: 4326 and 900913 support. Besides i tried to use a wms base layer (with EPSG:4326) and it works without any problem.

Thanks for the help and sorry for my english.

Juan David Rondón Díaz
Bogotá, Colombia

Here is the code:

<!DOCTYPE html> 
<html lang='es'> 
<head> 
    <meta charset='utf-8' /> 
	<title>Cuenca Río Bogotá</title>	
    <script type='text/javascript' src='OpenLayers.js'></script>
    <script type='text/javascript'>

    var map, info;

	function init() {

            var options = {
                projection: new OpenLayers.Projection("EPSG:4326"),
                displayProjection: new OpenLayers.Projection("EPSG:4326")
            };	

        map = new OpenLayers.Map('map_element', options);

		var base = new OpenLayers.Layer.OSM("OpenStreetMap (Mapnik)");

		var base2 = new OpenLayers.Layer.WMS(
			'Base layer',
			'http://vmap0.tiles.osgeo.org/wms/vmap0',
			{layers: 'basic'},
			{isBaseLayer: true}
		);

        var rio = new OpenLayers.Layer.WMS(
           'Rio Bogota',
            'http://host.com/cgi-bin/mapserv.exe?map=C:/OSGeo4W/apache/maps/r_bogota2.map',
           {layers: 'Cuenca Rio Bogota',
          visibility: true,  transparent: true}            
        );

        map.addLayers([base2,base,rio]);

        info = new OpenLayers.Control.WMSGetFeatureInfo({
            url: 'http://host.com/cgi-bin/mapserv.exe?map=C:/OSGeo4W/apache/maps/r_bogota2.map', 
            title: 'Click para consultar',
            queryVisible: true,
            eventListeners: {
                getfeatureinfo: function(event) {
                    map.addPopup(new OpenLayers.Popup.FramedCloud(
                        "chicken", 
                        map.getLonLatFromPixel(event.xy),
                        null,
                        event.text,
                        null,
                        true
                    ));
                }
            }
        });
        map.addControl(info);
        info.activate();

        map.addControl(new OpenLayers.Control.LayerSwitcher({}));

		if(!map.getCenter()){
			map.zoomToMaxExtent();
		}
    }

    </script>
</head>

<body onload='init();'>
    <div id='map_element' style='width: 800px; height: 600px;'>
	</div>
</body>
</html>