Resium brings React’s component lifecycle to Cesium. The relationship between Cesium elements and React’s lifecycle is as follows.
constructor: The Cesium element is initialized (the Cesium element of some components are initialized at mount time).
render: Nothing is rendered, because the object passed to children via React’s context API does not exist in this time.
componentDidMount: The Cesium element is mounted. After this,
forceUpdateis called and re-render children.
render: Children of the component are rendered. DOM never be rendered except root components (Viewer and CesiumWidget).
componentDidUpdate: Changed properties of the Cesium element are updated. If “Cesium read only properties” are changed, the Cesium element will be reinitialized.
componentWillUnmount: The Cesium element is unmounted and destroyed.