What to do with the warning: "VirtualizedList: You have a large list that is slow to update"?

Question

React Native

There is a heavy json file that is loaded into FlatList.
And periodically this message appears:

VirtualizedList: You have a large list that is slow to update - make sure your renderItem function renders components that follow React performance best practices like PureComponent, shouldComponentUpdate, etc. Object {
  "contentLength": 5758.33349609375,
  "dt": 826,
  "prevDt": 729,
}

I tried googling but couldn't find what exactly to do.

Answer 1

this is just a warning that your list is rendering for a long time and it is suggested to look for an opportunity to optimize it, for example, rewrite renderItem with PureComponent or write shouldComponentUpdate