How to paginate to previous page using AngularFire, Firestore and Firebase

Question

Sorry I have seen this question has been asked many times in different ways here such as:

• Howto paginate back to previous pages in a Angular(6) and firebase Fires

Answer 1

As of firebase@7.3.0 you can use the Query.limitToLast(n: number) method - makes it much easier to move backward with paginated data.

Your implementation details might look something like this:

function nextPage(last) {
   return ref.orderBy('age').startAfter(last.age).limit(3);
}

function prevPage(first) {
   return ref.orderBy('age').endBefore(first.age).limitToLast(3);
}