[Users] Keeping Selected Layers When Replacing Child Nodes

[IT Intern]

Ok so far I have been able to find a way to access the properties of
nodes...now I am struggling to find out if there is anyway to access the
properties of the node's leafs?  If anyone know please help me, I think if I
have that I will be able to carry out the desired task :)

Some code of my approach:

var i;
                            var j = 0;
                            var selectedLayers = new Array();
                            while(layerRoot.lastChild.hasChildNodes()){

alert(layerRoot.lastChild.firstChild.childNodes.length); //This returns 0,
but the childNodes here are leafs :(
                                for(i = 0; i <
layerRoot.lastChild.firstChild.childNodes.length; i++){

if(layerRoot.lastChild.firstChild.childNodes[i].isSelected()){
                                        selectedLayers[j] =
layerRoot.lastChild.firstChild.childNodes[i].attributes.text;
                                        alert(selectedLayers[j]);
                                        j++;
                                    }
                                }


layerRoot.lastChild.removeChild(layerRoot.lastChild.firstChild);
                            }
                            layerRoot.removeChild(layerRoot.lastChild);
                        }

Thanks for taking the time to consider my questions,

elshae

On Tue, Oct 19, 2010 at 4:17 PM, IT Intern <itintern12 at gmail.com> wrote:

> Hello GeoExt Friends,
>
> So I have been using the GeoExt and Ext libraries to develop my map browser
> and now there's a feature I'd like to have, but don't know how to go about
> it :)
>
> So far everything is working.  What I have is a tree panel that when a menu
> is clicked a parent node with layer containers is added to the tree.  The
> layers in these containers are in different languages, so as the user
> toggles between the languages in the menu, it be nice if the layers in the
> previous language correspond to the language that is currently selected.  I
> hope you will understand what I am asking to do.  I guess a good starting
> point would be, is there a way to "get" which layers are selected in a layer
> container?  Thanks for your time, below is some relevant code:
>
> //So there are many layers, one each per language...
>
> var chn_townships = new OpenLayers.Layer.WMS(
>                             "Townships (Chinese trans)", "
> http://localhost:8080/geoserver/wms", {layers: 'cite:chn_townships',
> transparent: true}, {isBaseLayer: false, displayInLayerSwitcher: true,
> visibility: false}
>                        );
>
>             var tib_townships = new OpenLayers.Layer.WMS(
>                             "Townships (Tibetan trans)", "
> http://localhost:8080/geoserver/wms", {layers: 'cite:tib_townships',
> transparent: true}, {isBaseLayer: false, displayInLayerSwitcher: true,
> visibility: true}
>                        );
>
> //The layers are stored in layer stores...
> var tibLands = new GeoExt.data.LayerStore({
>                 map: map,
>                 initDir: 0,
>                 layers: [tib_villages, tib_townships, tib_farms,
> tib_countys]
>             });
>
>             var chnLands = new GeoExt.data.LayerStore({
>                 map: map,
>                 initDir: 0,
>                 layers: [chn_villages, chn_townships, chn_farms,
> chn_countys]
>             });
>
> //Menu for users to select language
> var languageMenu = new Ext.menu.Menu({
>                 id: 'mainMenu',
>                 style: {
>                     overflow: 'visible'     // For the Combo popup
>                 },
>                 items: [
>                     // A Field in a Menu
>                     {
>                         text: 'Chinese',
>                         checked: false,
>                         group: 'theme',
>                         icon: './gif/cn.gif',
>                            handler: checkHandler
>                     },{
>                         text: 'English',
>                         checked: true,
>                         group: 'theme',
>                         handler: checkHandler
>                     },{
>                         text: 'Tibetan',
>                         checked: false,
>                         group: 'theme',
>                         handler: checkHandler
>                         }
>                 ]
>             });
>
> //The handler function that listens to the users selection on the menu
> (This is where I want the magic to happen ;)
> function checkHandler(item, checked) {
>                     var tibetContainer, chineseContainer;
>
>                     if(item.text == 'Tibetan'){
>                         if(layerRoot.lastChild.id == 'chinese'){
>                             layerRoot.removeChild(layerRoot.lastChild);
>                         }
>
>                         tibetContainer = new Ext.tree.TreeNode({
>                             text: "Tibetan Labels",
>                             expanded: true,
>                             id: 'tibet'
>                         });
>
>                         tibetContainer.appendChild(new
> GeoExt.tree.OverlayLayerContainer({
>                             text: "Lands (Tibetan trans)",
>                             layerStore: tibLands,
>                             expanded: false,
>                             loader: {param: "LAYERS"}
>                         }));
>
>                         tibetContainer.appendChild(new
> GeoExt.tree.OverlayLayerContainer({
>                             text: "Natural Selection (Tibetan trans)",
>                             layerStore: tibNaturalLayers,
>                             expanded: false,
>                             loader: {param: "LAYERS"}
>                         }));
>
>                         tibetContainer.appendChild(new
> GeoExt.tree.OverlayLayerContainer({
>                             text: "Points of Interest (Tibetan trans)",
>                             layerStore: tibPointOfInterest,
>                             expanded: false,
>                             loader: {param: "LAYERS"}
>                         }));
>
>                         layerRoot.appendChild(tibetContainer);
>
>                     }
>                     else if(item.text == 'Chinese'){
>
>                         chineseContainer = new Ext.tree.TreeNode({
>                             text: "Chinese Labels",
>                             expanded: true,
>                             id: 'chinese'
>                         });
>
>                         chineseContainer.appendChild(new
> GeoExt.tree.OverlayLayerContainer({
>                             text: "Lands (Chinese trans)",
>                             layerStore: chnLands,
>                             expanded: false,
>                             loader: {param: "LAYERS"}
>                         }));
>
>                         chineseContainer.appendChild(new
> GeoExt.tree.OverlayLayerContainer({
>                             text: "Natural Selection (Chinese trans)",
>                             layerStore: chnNaturalLayers,
>                             expanded: false,
>                             loader: {param: "LAYERS"}
>                         }));
>
>                         chineseContainer.appendChild(new
> GeoExt.tree.OverlayLayerContainer({
>                             text: "Points of Interest (Chinese trans)",
>                             layerStore: chnPointOfInterest,
>                             expanded: false,
>                             loader: {param: "LAYERS"}
>                         }));
>
>                         if(layerRoot.lastChild.id == 'tibet'){
>
> //layerRoot.removeChild(layerRoot.lastChild);
>                             layerRoot.replaceChild(chineseContainer,
> layerRoot.lastChild)  //thought this might have done it, this just replaces
> the nodes but not the layers selected to the new ones :(
>                         }else
>                         {layerRoot.appendChild(chineseContainer);}
>
>                     }
>
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