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Michael Lustig - halfjew22@gmail.com
Michael Lustig - halfjew22@gmail.com

Posted on • Updated on

How can I use refs to set callbacks on a FlatList?

StackOverflow Post

I'm trying to use refs to set the onEndReached prop of my FlatList imperatively. Is there a way to do that?

I've modified an example from the PR that adds setNativeProps that toggles the color from black to white on an interval, but can't get onEndReached or onScroll to be called.

Can anyone help me understand what I'm doing wrong?

export default class Testing extends React.Component {
  componentDidMount() {
    let tick = 0
    this.list.setNativeProps({
      onEndReached: info => {
        // NEVER CALLED ๐Ÿ˜ข
        console.log('L231 on Scroll info ===', info)
      },

      onScroll: info => {
        // NEVER CALLED ๐Ÿ˜ข
        console.log('L250 info ===', info)
      },

      // Background DOES flash red on load... ๐Ÿค” 
      style: { backgroundColor: 'red' }
    })
    setInterval(() => {
      this.list.setNativeProps({
        onEndReached: info => {
          console.log('L231 on Scroll info ===', info)
        },

        // Background DOES toggle black and white... ๐Ÿค” 
        style: { backgroundColor: tick++ & 2 ? 'white' : 'black' }
      })
    }, 1000)
  }

  render() {
    return (
      <View style={styles.container}>
        <FlatList
          ref={component => (this.list = component)}
          style={{ backgroundColor: 'black' }}
          data={[{ key: 'a' }, { key: 'b' }]}
          renderItem={({ item }) => <Text>{item.key}</Text>}
        />
      </View>
    )
  }
}
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