[Users] Base Layer Does Not Display on Initial Load
Andreas Hocevar
ahocevar at opengeo.org
Mon Sep 27 16:51:35 CEST 2010
On Sep 27, 2010, at 16:15 , IT Intern wrote:
> Andreas,
>
> What if I am using an Ext.Panel like this?
>
> var map = new OpenLayers.Map(options);
Make sure that there is no div in your options.
>
> var mapPanel = new GeoExt.MapPanel({
> title: "Map",
> map: map,
You can do this, but then you also have to destroy the map manually.
> center: map.setCenter(new OpenLayers.LonLat(93.9, 29.53).transform(new OpenLayers.Projection("EPSG:4326"), map.getProjectionObject())),
This is wrong. Just provide the center here. Don't call map.setCenter.
> zoom: 9,
> region: "center",
> bbar: [{
> xtype: "label",
> text: "Scale = 1 : "
> }],
> items: [{
> xtype: "gx_zoomslider",
> vertical: true,
> height: 300,
> x: 10,
> y: 20,
> plugins: new GeoExt.ZoomSliderTip()
> }]
> });
>
> new Ext.Panel({
> width: 1800,
> height: 600,
> layout: "border",
> renderTo: document.body,
> items: [mapPanel, layerTree]
> //items: [mapPanel, groupLayerNode]
> });
>
> Because I tried with just using map: options, for the mapPanel and then to refer back to my map was a pain. I tried using mapPanel.map everywhere the original variable map was used and my code broke.
var mapPanel = new GeoExt.MapPanel({});
var map = mapPanel.map;
// now map is an instance of OpenLayers.Map;
> I also added renderTo: document.body, but since I have the Ext.Panel, it placed the mapPanel in a separate div, even after specifying width and height. My only other guess is maybe I need to get rid of the Ext.Panel, but then do I add the items: [layerTree] to the mapPanel instead? I really like having the Ext.Panel instead and adding things to it...
See above. The only reason why it could fail now is a "div" property in your map options.
Regards,
Andreas.
>
> Thank you,
>
> elshae
>
> On Sat, Sep 25, 2010 at 6:58 AM, Andreas Hocevar <ahocevar at opengeo.org> wrote:
> Hi,
>
> you have to render the MapPanel to somewhere. Either add "renderTo: document.body" to the mapPanel's configuration, or add it to a container. If you do the former, you also have to configure a width and height on the mapPanel.
>
> Regards,
> Andreas.
>
> On Sep 24, 2010, at 19:19 , IT Intern wrote:
>
> > Jason,
> >
> > I am using Google Streets actually :). It just isn't working out for me atm...
> >
> >
> > Andreas,
> >
> > I tried both suggestions. I got rid of the 'map' parameter in the map instantiation and had the same result, the layer was blank. Then I tried again with using my options variable in my mapPanel and nothing loaded up at all when I did this :(
> > My entire page was blank...
> >
> > Thanks,
> >
> > elshae
> >
> > On Fri, Sep 24, 2010 at 10:39 AM, Andreas Hocevar <ahocevar at opengeo.org> wrote:
> > Hi,
> >
> > the problem here is that you configure the OpenLayers map in the wrong mode. See below:
> >
> > On Sep 23, 2010, at 21:43 , IT Intern wrote:
> >
> > > Hello GeoExt users,
> > >
> > > This one's gotten me totally stumped. I have some base layers and a few wms overlays. When my page loads it shows the base layer for a quick second and then goes blank as it loads my overlays. It stays blank until I click the map, etc. Then it displays properly. I've Googled all sorts of things concerning this sort of issue and have come up with nothing that gives me a hint as to why this could be. This never happened to me before until I started using GeoExt to display my map. Is it something in code I must write for GeoExt or OpenLayers so that this doesnt happen? It's driving me crazy!!!
> > >
> > > Code:
> > >
> > > //Base Layers
> > >
> > > var ghyb = new OpenLayers.Layer.Google(
> > > "Google Hybrid",
> > > {type: google.maps.MapTypeId.HYBRID, numZoomLevels: 20}
> > > );
> > >
> > > var gmap = new OpenLayers.Layer.Google(
> > > "Google Streets", // the default
> > > {numZoomLevels: 20},{visibility: true}
> > > );
> > >
> > > var osm = new OpenLayers.Layer.OSM();
> > >
> > > //.....
> > > ....
> > > ....
> > >
> > > var options = {
> > > controls: [new OpenLayers.Control.Navigation()],
> > > maxExtent: new OpenLayers.Bounds(-20037508.34, -20037508.34, 20037508.34, 20037508.34),
> > > maxResolution: "auto",
> > > projection: new OpenLayers.Projection("EPSG:900913"),
> > > units: 'm',
> > > allOverlays: false
> > > }
> > >
> > >
> > > var map = new OpenLayers.Map('map', options);
> >
> > Wrong! If at all, use the following instead:
> >
> > var map = new OpenLayers.Map(options);
> >
> > You don't want to render the map at this point, so you have to configure it without a map div.
> >
> >
> > > map.addLayers([gmap, ghyb, osm, all_chn, all_tib, chn_bridges, tib_bridges, chn_countys, tib_countys, chn_farms, tib_farms, chn_glaciers, tib_glaciers, chn_grazing, tib_grazing, chn_hwyCrew, tib_hwyCrew, chn_hospitals, tib_hospitals, chn_lakes, tib_lakes, chn_monastaries, tib_monastaries, chn_pass, tib_pass, chn_rivers, tib_rivers, chn_townships, tib_townships, chn_villages, tib_villages]);
> > >
> > > var mapPanel = new GeoExt.MapPanel({
> > > title: "Map",
> > > map: map,
> >
> > Now the preferred way to configure a MapPanel would be to remove the "var map = ..." above entirely, and configure the map here:
> >
> > map: options,
> > layers: [gmap, ghyb, osm, all_chn, all_tib, chn_bridges, tib_bridges, chn_countys, tib_countys, chn_farms, tib_farms, chn_glaciers, tib_glaciers, chn_grazing, tib_grazing, chn_hwyCrew, tib_hwyCrew, chn_hospitals, tib_hospitals, chn_lakes, tib_lakes, chn_monastaries, tib_monastaries, chn_pass, tib_pass, chn_rivers, tib_rivers, chn_townships, tib_townships, chn_villages, tib_villages]
> >
> > Regards,
> > Andreas.
> >
> > > center: map.setCenter(new OpenLayers.LonLat(93.9, 29.53).transform(new OpenLayers.Projection("EPSG:4326"), map.getProjectionObject())),
> > > zoom: 9,
> > > region: "center",
> > > bbar: [{
> > > xtype: "label",
> > > text: "Scale = 1 : "
> > > }],
> > > items: [{
> > > xtype: "gx_zoomslider",
> > > vertical: true,
> > > height: 300,
> > > x: 10,
> > > y: 20,
> > > plugins: new GeoExt.ZoomSliderTip()
> > > }]
> > > });
> > >
> > > var layerRoot = new Ext.tree.TreeNode({
> > > text: "All Layers",
> > > expanded: true,
> > > autoLoad: true
> > > });
> > >
> > > //Is there something to set here???
> > > layerRoot.appendChild(new GeoExt.tree.BaseLayerContainer({
> > > text: "Base Layers",
> > > map: map,
> > > layerStore: mapPanel.layers,
> > > expanded: true,
> > > autoLoad: true
> > > }));
> > >
> > > //.....
> > >
> > > Thank you very much, I appreciate any suggestions :),
> > >
> > > elshae
> > >
> > >
> > >
> > > _______________________________________________
> > > Users mailing list
> > > Users at geoext.org
> > > http://www.geoext.org/cgi-bin/mailman/listinfo/users
> >
> >
> >
> > --
> > Andreas Hocevar
> > OpenGeo - http://opengeo.org/
> > Expert service straight from the developers.
> >
> >
> > _______________________________________________
> > Users mailing list
> > Users at geoext.org
> > http://www.geoext.org/cgi-bin/mailman/listinfo/users
>
>
>
> --
> Andreas Hocevar
> OpenGeo - http://opengeo.org/
> Expert service straight from the developers.
>
>
> _______________________________________________
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> http://www.geoext.org/cgi-bin/mailman/listinfo/users
--
Andreas Hocevar
OpenGeo - http://opengeo.org/
Expert service straight from the developers.
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