Lazy list loading

In this section, you’ll implement a different kind of list: one that scrolls infinitely. Sometimes, users don’t actually know what they’re looking for, so filtering or sorting isn’t going to help. Think about the Facebook news feed you see when you log in to your account; it’s the main feature of the application, and rarely are you looking for something specific. You need to see what’s going on by scrolling through the list.

To do this using a FlatList component, you need to be able to fetch more API data when the user scrolls to the end of the list. To get an idea of how this works, you need a lot of API data to work with, and generators are great at this. So, let’s modify the mock that you created in the Fetching list data section’s example so that it just keeps responding with new data:

function* genItems() {
  let cnt = 0;
  while (true) {
    yield `Item ${cnt++}`;
  }
}
let items = genItems();...