KML

This sample shows how to load KML data with Network Links and Ground Overlay features, and how to create a KML content tree user interface showing the hierarchical structure of KML data.

When you use KMLModel with KMLLayer then the underlying KMLCodec decodes KML data and returns a Cursor of KMLPlacemarkFeature's only, that are automatically visualized on a map.
KMLNetworkLinkFeature's and KMLGroundOverlay's have to be visualized differently. KMLCodec emits the KMLNetworkLink event and the KMLGroundOverlay event when these features are encountered in KML data. A custom event handler can consume these events by creating a new KML layer for KMLNetworkLink and a new raster layer for KMLGroundOverlayFeature. For more information please consult the KML API documentation and the how-to article on visualization of KML data.

At the end of the decoding process, the codec emits a single KMLTree event that reports the whole structure of KML data starting with the topmost KMLDocumentFeature, which is a container feature that includes all KML feature types.

The sample builds the KML content tree user interface based on the emitted KMLTree and automates creation of new layers for network links and ground overlays.
Instructions:

• Use the fold icon to expand or collapse a KML container item. The initial fold state of KML containers depends on KML open element.
• Click on the visibility icon to control the visibility of features. The initial visibility of KML features depends on KML visibility element. When the container's visibility is changed then the new visibility is propagated to all children.
• Double-click on an item to performs an animated pan to the feature or a collection of features the item represents.
• When a KML Network Link feature is defined with the refreshMode equal to onInterval then the created KML layer refreshes its data every n seconds as specified initially in KML refreshInterval element. In such cases yuu can change the refresh interval using teh Refresh button.
• When data is loaded a busy icon show up for a KML layer item, that represents the root layer or a layer created for a network link.

You can drag and drop a KML or a KMZ file on the map. KMZ-files, which are zipped KML-files. Only the top level KML file in the KMZ and its image resources will be processed.

The sample code is written in TypeScript with JSX. The user interface is built using the React library.