Indicates if there is a next page of data.
Returns true if the current page is not the last
page in the dataset.
Returns false if the current page is the last
page in the dataset.
Calling hasNextPage() on a write-only dataset causes an error.
Note:
A dataset needs to load its data before you call its hasNextPage() function.
Usually a dataset finishes loading a short time after the page it is on finishes
loading. So if you call hasNextPage() inside the page’s onReady()
event handler, the dataset might not be ready yet.
To call hasNextPage() as soon as possible after a page loads, use the dataset's
onReady() function inside the page’s onReady()
event handler to ensure that both the page and the dataset have finished loading.