Show extent

This sample demonstrates how to watch for changes on the map view.

How to use the sample

Clone the sample repo and copy this widget's folder (within samples/widgets) to the client/your-extensions/widgets folder of your Experience Builder installation.

How it works

A class property onActiveViewChange for the widget is assigned to the function JimuMapView. This function uses the jimuMapView.view.watch() method, which takes two imput parameters, the extent property and a callback function to execute each time the extent property changes. The setState method is called to re-render the widget with the updated state.

         
onActiveViewChange = (jimuMapView: JimuMapView) => {
  if(!this.extentWatch){
    this.extentWatch = jimuMapView.view.watch('extent', extent => { 
      this.setState({
        extent
      })
    });
  }
}