feat: add example for dependent attribute values

examples/08.attribute-dependencies.ts

@@ -0,0 +1,20 @@
+// title: dynamic attributes depending on each other
+
+import {Marker} from './lib/marker';
+
+// dynamic attributes can be written to reliably depend on the current value
+// of another attribute, for example to make colors depend on the icon shown
+// or make colors depend on each other. Note that this also works when
+// depending on other dynamic attributes.
+//
+// Returning undefined for the borderColor causes the borderColor to be set
+// automatically via the color attribute.
+
+export default (map: google.maps.Map) => {
+  const marker = new Marker({
+    position: {lat: 53.55, lng: 10.05},
+    color: ({marker}) => (marker.hovered ? 'red' : 'green'),
+    borderColor: ({attr}) => (attr.color === 'red' ? 'black' : undefined),
+    map
+  });
+};