[GIS] Displaying KML Extended Data in OpenLayers

Question

I have just got a problem displaying extended data from a KML file in OpenLayers 2. I hope you can help me with this issue. I have already searched for a solution, but I do not find a real solution for it. I have to mention that I am not a programmer and just modify free available scripts and codes.

I have a standard KML file like:

<?xml version="1.0" encoding="utf-8" ?>
<kml xmlns="http://www.opengis.net/kml/2.2">
<Document id="root_doc">
<Style id="style1">
    <IconStyle>
      <Icon>
        <href>pr.png</href>
      </Icon>
    </IconStyle>
  </Style>
<Schema name="pr14" id="pr14">
    <SimpleField name="Description" type="string"></SimpleField>
    <SimpleField name="Nr." type="int"></SimpleField>
    <SimpleField name="Landkreis" type="string"></SimpleField>
    <SimpleField name="Lage (Koordinate X)" type="float"></SimpleField>
    <SimpleField name="Lage (Koordinate Y)" type="float"></SimpleField>
    <SimpleField name="Kapazität" type="string"></SimpleField>
</Schema>
<Folder><name>P+R pr14</name>
  <Placemark>
    <name>P+R Altenbach</name>
    <description>8011018</description>
    <ExtendedData><SchemaData schemaUrl="#pr14">
        <SimpleData name="Nr.">1</SimpleData>
        <SimpleData name="Landkreis">LL</SimpleData>
        <SimpleData name="Lage (Koordinate X)">51.356068</SimpleData>
        <SimpleData name="Lage (Koordinate Y)">12.681333</SimpleData>
        <SimpleData name="Kapazität">0</SimpleData>
    </SchemaData></ExtendedData>
   <styleUrl>#style1</styleUrl> 
      <Point><coordinates>12.681333,51.356068</coordinates></Point>
  </Placemark>

</Folder>
</Document></kml>

Now, I would like to display beside of the "name" and "description" field which work fine also the attributes from Extended Data fields.

 var kmllayer2 = new OpenLayers.Layer.Vector("P+R Plätze", {
                maxResolution: map.getResolutionForZoom(9),
            strategies: [new OpenLayers.Strategy.Fixed()],
            protocol: new OpenLayers.Protocol.HTTP({
                url: "pr14_1.kml",
                format: new OpenLayers.Format.KML({
                    extractStyles: true,
                    extractAttributes: true,
                    maxDepth: 2

To display the name in my popup I use '+feature.attributes.name+', but I cannot sort out how to modify this to get also the extended data values like 'Kapazität" for example.

var controls2 = {
          selector2: new OpenLayers.Control.SelectFeature(kmllayer2, { onSelect: createPopup2, onUnselect: destroyPopup2 })
        };

        function createPopup2(feature) {
          feature.popup = new OpenLayers.Popup.FramedCloud("pop",
              feature.geometry.getBounds().getCenterLonLat(),
              null,
              '<div class="markerContent"><h3><font color="004A84">'+feature.attributes.name+'</font></h3></div>',
              null,
              true,
              function() { controls2['selector2'].unselectAll(); }
          );

          //feature.popup.closeOnMove = true;
          map.addPopup(feature.popup);
        }

        function destroyPopup2(feature) {
          feature.popup.destroy();
          feature.popup = null;
        }

         map.addControl(new OpenLayers.Control.LayerSwitcher({'ascending':false}));


        map.addControl(controls2['selector2']);
        controls2['selector2'].activate();

Could you give me a hint?

Answer 1

The solution for it is:

+feature.attributes."SimpleData name".value+

Example:

+feature.attributes.Kapazität.value+