Logic of dialog closed in office javascript API. (Outlook add-in)

How to check if dialog box is closed in outlook add-in?

I want to clear localstorage of browser once I close the dialog box.

I am using Office.context.ui.displayDialogAsync for dialogs.

When you create the dialog, you need to get the dialog handle, and add a dialog closed event listener:

export async function displayDialogAsync (dialogUrl: string): Promise<void> {
    return new Promise<void>(resolve => {
        
        const dialogClosed = async (_: any): Promise<void> => {
            // do whatever you need when the dialog is closed  
            resolve();
        };
    
        Office.context.ui.displayDialogAsync(url, dialogOptions, (result: Office.AsyncResult) => {
            dialog = result.value;
            dialog.addEventHandler(Office.EventType.DialogEventReceived, dialogClosed);
        });
    });
}