How to zoom to a KMLLayer?

[davidoloughlin]

I've created a new KMLLayer, added it to my map, and I can see it once I manually pan and zoom to it. I can't seem to figure out how to programmatically zoom to the new layer. I try to change the map extent to the new layer's extent (e.g., kmlLayer.fullExtent) but KMLLayer appears to only implement initialExtent, which is huge.

[FC_Basson]

It seems possible for a vector KML.  The API reference page for KML layers (KMLLayer | API Reference | ArcGIS API for JavaScript 3.17 ) shows how to do it (near the top).

From the API reference page:

The following code snippet shows how to get a KML layer's layers, checks that a layer has graphics, unions the layer extents and then zooms to the new extent:

  var kmlExtent, layers = kml.getLayers();
  dojo.forEach(layers, function(lyr) {
    if ( lyr.graphics && lyr.graphics.length > 0 ) {
      var lyrExtent = esri.geometry.geographicToWebMercator(
        esri.graphicsExtent(lyr.graphics)
      );
      if ( globals.kmlExtent ) {
        kmlExtent = kmlExtent.union(lyrExtent);
      } else {
        kmlExtent = lyrExtent;
      }
  });
  map.setExtent(kmlExtent);

Is your KML layer a ground overlay?

[davidoloughlin]

Thanks very much for the code snippet. I've tried using ground overlays but also just a simple polygon, Wyoming.kml used here. In both cases, kml.getLayers() returns [],  no layers to iterate through. 

[FC_Basson]

Have you tried your KML source in the sandbox example?  That kml returns an array with a single layer object.

[davidoloughlin]

Thanks very much for your patience. I'm obviously missing something but how can you tell? I modify this sandbox example, adding the line 'console.log(kml.getLayers())' below the line 'map.addLayer(kml);', then run it. Looking at the console (in chrome anyway), I just see '[]'.

[FC_Basson · Accepted solution]

In the sandbox example, change the kml variable scope to a global variable (just remove the var declaration).

Then in the Chrome console, change the console output to log the sandbox's.

Then you can run kml.getLayers() to view the kml layers.

[davidoloughlin]

Thanks. That explains it. Needed to move my kml.getLayers() loop into the "load" event handler function.