multiselecttree API/lazy loading

Hi, Mahesh,

I prepared an example that simulated an API call for the MultiSelectTree component by loading a `loadingPanel` component to the MultiSelectTree element when an item is expanded.

In the below demo, I added the loadingPanel to the MultiSelectTree element using ReactDOM.createPortal in the LoadingPanel component. In addition, I am setting the `loading` state variable to true in the `onExpandChange` event handler and in that case the panel will appear since it is rendered conditionally with the `loading` variable.

Moreover, in the onExpandChange method, I am setting a 1000ms timeout in order to simulate an API call. Inside the `setTimeout` method, I am setting the new expanded state and `loading` to false:

• https://stackblitz.com/edit/react-vrr2jz?file=app%2Fmain.jsx

Please check the above example and let me know if it matches what you need.

Regards,
Wissam
Progress Telerik