React native pull down refresh to fetch data

Question

I am using React native to show the data from fetch API. But when the data update, it still shows the old data. I'm confusing how to do the pull down refresh inside my code.

class YourActivitiesScreen extends Component{
    constructor(props) {
        super(props);
        this.state = {
            activitiesList: [],   
        }
    };
    componentDidMount(){
        AsyncStorage.getItem('id_token').then(this.getData)
    }
    getData=(token)=>{
        console.log(token)
       fetch('http://192.168.0.1:8887/api/auth/activities/your',{
            method: 'POST',
            headers:{
                'Accept': 'application/json',
                'Content-Type': 'application/json',
                'Authorization': 'Bearer ' +token,
            },
        })
        .then((response) => response.json())

        .then((res) => {
            if(res.yourActivity)
            {
                let yourActivity = res.yourActivity
                this.setState({activitiesList: yourActivity})
            }
        })
        .catch((e) => console.log('Error: ', e))
        }
        renderItem = (item) => {
            return (
              <TouchableOpacity
                onPress={() => 
                  this.props.navigation.navigate('Details',{activity: item})
                }
              >
                <View style={styles.item}>
                  <Text style={styles.itemtext}>{item.name} </Text>
                </View>
              </TouchableOpacity>
            );
          }
    render(){
        const listActivities = this.state.activitiesList

        return (
                <View stlye={styles.container}>
                    <SafeAreaView>
                        <FlatList
                            data = {listActivities}
                            renderItem={({ item }) => this.renderItem(item)}
                            keyExtractor={item => item.id}
                            style={styles.list}
                        />
                    </SafeAreaView>
                </View>
        )
        }
}

Is that i need to do something to let the componentDidMount run again while I make a pull down action? If yes can someone explain to me how to do so?

Answer 1

You must use the extraData FlatList prop each time you update the data.

extraData

A marker property for telling the list to re-render (since it implements PureComponent ). If any of your renderItem , Header, Footer, etc. functions depend on anything outside of the data prop, stick it here and treat it immutably.

Set extraData prop with the activitiesList object:

render(){
  const listActivities = this.state.activitiesList

  return (
    <View stlye={styles.container}>
      <SafeAreaView>
        <FlatList
          data={listActivities}
          extraData={listActivities}
          renderItem={({ item }) => this.renderItem(item)}
          keyExtractor={item => item.id}
          style={styles.list}
        />
      </SafeAreaView>
    </View>
  )
}

Answer 2

Please try to use onRefresh prop in FlatList. Ref: https://reactnative.dev/docs/flatlist#onrefresh Note: Please make sure to set the refreshing prop correctly when use onRefresh in FlatList.

Implement pull to refresh FlatList