I've been dealing with the problem mentioned below for a few days ... My problem is with ReactNative FlatList. I use Expo and instead of using simulation I use real devices (Iphone 11 and Xiaomi Redmi Note7).
With the code below, FlatList renders smoothly on Iphone 11, while it enters an endless loop on mobile phones with Android operating systems such as Xiaomi and Samsung. View under RenderItem function comes but its content is not available.
Also, although there are three objects under state.data(checked with console.log), FlatView is rendered infinitely.
Has anyone encountered this situation before? How can I resolve this situation?
Thanks in advance.
Here is my code;
/*
Lights
Ahmet BOZ
21.11.2020
*/
import React, {Component} from 'react';
import { StyleSheet, Text, View, ScrollView, Button, TouchableOpacity, FlatList } from 'react-native';
import Warning from "../components/Warning";
import Logo from "../components/Logo";
import Light from '../components/Light';
import axios from 'axios';
import Loading from '../components/Loading';
export default class Lights extends Component {
state = {
loading: true,
data:[]
}
setAllLights = async () => {
const {data : data} = await axios.get('http://API_URL')
this.setState({
data,
loading: false
})
}
componentDidMount(){
this.setAllLights();
}
renderLights = ({item, index}) => {
return(
<TouchableOpacity
onPress={() => this.props.navigation.navigate('LightDetail', { lightid: item.light_id,})}
style={styles.svLight}>
<Text style={{color:'#ffca3a'}}>{item.light_name}</Text>
</TouchableOpacity>
)
}
render() {
const {lightName, lightId} = this.state;
return (
<View style={styles.LightsWrapper}>
{this.state.loading && <Loading />}
<View style={styles.main}>
<View style={styles.svInformation}><Text style={{color:'#efefef'}}>All lights sorted by alphabetical</Text></View>
<FlatList style={styles.sv}
renderItem={this.renderLights}
numColumns={3}
keyExtractor={item => item.light_id}
data = {this.state.data}
/>
</View>
</View>
);
}
}
const styles = StyleSheet.create({
LightsWrapper: {
flex:1,
},
main: {
flex:1,
backgroundColor:'#1b263b',
},
svInformation: {
justifyContent:'center',
alignItems:'center',
backgroundColor:'brown',
paddingVertical:5,
marginBottom:5,
},
svRow: {
paddingVertical:3,
flexDirection:'row',
justifyContent:'space-between',
},
svLight:{
flex:1,
borderColor:'#fff',
justifyContent:'center',
alignItems:'center',
paddingVertical:20,
borderWidth:1,
borderColor:'#ffca3a',
flexDirection:'row',
borderRadius:3,
marginBottom:2,
}
});
Related
I'm trying to apply layout animation to a FlatList upon adding and deleting a goal (list item) using the Reanimated API. I'm mainly following this tutorial from the Reanimated docs but I don't know why the animation is not applied when list items are added or removed. I should also inform that I'm only testing this on an Android device. Here is the code:
App.js (contains FlatList)
import { useState } from "react";
import { Button, FlatList, StyleSheet, View } from "react-native";
import GoalInput from "./components/GoalInput";
import GoalItem from "./components/GoalItem";
export default function App() {
const [goalList, setGoalList] = useState([]);
const [isModalOpen, setIsModalOpen] = useState(false);
const styles = StyleSheet.create({
appContainer: {
paddingTop: 50,
},
});
function startAddGoalHandler() {
setIsModalOpen(true);
}
// spread existing goals and add new goal
function addGoalHandler(enteredGoalText) {
setGoalList((currentGoals) => [
...currentGoals,
{ text: enteredGoalText, id: Math.random().toString() },
]);
}
function deleteGoalHandler(id) {
setGoalList((currentGoals) =>
currentGoals.filter((existingGoals) => existingGoals.id !== id)
);
}
return (
<View style={styles.appContainer}>
<Button
title='Add New Goal'
color='indigo'
onPress={startAddGoalHandler}
/>
{isModalOpen && (
<GoalInput
isModalOpen={isModalOpen}
setIsModalOpen={setIsModalOpen}
onAddGoal={addGoalHandler}
></GoalInput>
)}
<FlatList
keyExtractor={(item, index) => {
return item.id;
}}
data={goalList}
renderItem={(itemData) => {
return (
<GoalItem
onGoalDelete={deleteGoalHandler}
itemData={itemData}
/>
);
}}
/>
</View>
);
}
GoalItem.js (list item)
import React from "react";
import { Pressable, StyleSheet, Text } from "react-native";
import Animated, { Layout, LightSpeedInLeft, LightSpeedOutRight } from "react-native-reanimated";
const GoalItem = ({ itemData, onGoalDelete }) => {
const styles = StyleSheet.create({
goalCards: {
elevation: 20,
backgroundColor: "white",
shadowColor: "black",
height: 60,
marginHorizontal: 20,
marginVertical: 10,
borderRadius: 10,
},
});
return (
<Animated.View
style={styles.goalCards}
entering={LightSpeedInLeft}
exiting={LightSpeedOutRight}
layout={Layout.springify()}
>
<Pressable
style={{ padding: 20 }}
android_ripple={{ color: "#dddddd" }}
onPress={() => onGoalDelete(itemData.item.id)}
>
<Text style={{ textAlign: "center" }}>
{itemData.item.text}
</Text>
</Pressable>
</Animated.View>
);
};
export default GoalItem;
I've even tried replacing the FlatList with View but to no avail. I suspect that Reanimated isn't properly configured for my project, if I wrap some components with <Animated.View>...</Animated.View> (Animated from Reanimated and not the core react-native module) for example the child components will not show. Reanimated is installed through npm
Any help is appreciated, thanks!
I want to display a custom message after successful record update when boolean value of recordUpdateSuccess become true and after 3seconds it should disappear.
{recordUpdateSuccess ? this.renderRecordUpdatedSucess() : null}
I have function to display message:
renderRecordUpdatedSucess = () => (
<View style={styles.sucessAlert}>
<Text style={styles.sucessAlert}>Record updated successfully.</Text>
</View>
)
I tried to use setTimeout() to display message but not working.
Any idea to acheive this one.
I don't want to use Toast, any third party library for this one.
Custom flash message (No external Library)
Working Example: https://snack.expo.io/#msbot01/1dcddc
import * as React from 'react';
import { Text, View, StyleSheet, TouchableOpacity } from 'react-native';
import Constants from 'expo-constants';
// You can import from local files
import AssetExample from './components/AssetExample';
// or any pure javascript modules available in npm
import { Card } from 'react-native-paper';
export default class App extends React.Component {
constructor(props) {
super(props);
this.state = {
flashMessage: false
}
}
onPress(){
this.setState({
flashMessage: true
},()=>{setTimeout(() => this.closeFlashMessage(), 3000)})
}
closeFlashMessage(){
this.setState({
flashMessage: false
})
}
render() {
return (
<View style={styles.container}>
<TouchableOpacity onPress={()=>{this.onPress()}}>
<Text>Click Me</Text>
</TouchableOpacity >
{this.state.flashMessage==true?
<View style={styles.flashMessage}>
<Text style={{color:'white'}}>This is custom Flash message</Text>
</View>
:
null
}
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
paddingTop: Constants.statusBarHeight,
backgroundColor: '#ecf0f1',
padding: 8,
},
flashMessage:{
position:'absolute',
backgroundColor:'green',
width:'100%',
justifyContent:'center',
alignItems:'center',
height:40,
top:0
}
});
I am developing React Native app.
I was able to solve all problems by myself but this is exception.
I am going to load another screen with bottom tab navigator.
For example, after user login to the app, it should show main home screen which has many pictures and many style sheet effects, icons. Because of that, after login confirm ( I mean after alert of the login confirm), the main home screen appears after a few seconds.
So I want to show some spinner in the login screen while loading main home screen in the background and when it is ready to show, erase spinner and show main home screen.
How can I do this?
My bottom tab navigator was simply created with createBottomTabNavigator() method.
So in your case you can do several things
You can use React Native Activity Indicator -> View
You can use Overlay Library -> react-native-loading-spinner-overlay -> View GitHub
If you like to make loading like facebook / instagram -> then use react-native-easy-content-loader -> View GitHub
Assume that you are using React Native Activity Indicator :
import { ActivityIndicator } from "react-native";
export default class HomeScreen extends Component {
constructor(props) {
super(props);
this.state = {
isLoading: true
};
}
//Get Home Screen Data API Action
componentDidMount() {
this.loadAPI(); // Call home screen get data API function
}
//Login API Function
loadAPI = () => {
this.setState({ isLoading: true }); // Once You Call the API Action loading will be true
fetch(API_URL, {
method: "POST",
headers: {
"Content-Type": "application/json"
}
})
.then(response => response.json())
.then(responseText => {
// You can do anything accroding to your API response
this.setState({ isLoading: false }); // After getting response make loading to false
})
.catch(error => {});
};
render() {
return (
<View style={{ flex: 1, justifyContent: "center", alignItems: "center" }}>
{this.state.isLoading && <ActivityIndicator color={"#fff"} />}
</View>
);
}
}
If you want to hide all the view until loading finish like images, so you can use custom library instead of Activity Indicator.
I have created my custom Loader component. Using this you can display built in ActivityIndicator or your custom gif loader image with overlay.
Loader.js
import React, { Component } from 'react';
import {
StyleSheet,
View,
Modal,
Image,
ActivityIndicator
} from 'react-native';
class Loader extends Component {
constructor(props) {
super(props);
this.state = {
isLoading: this.props.isLoading
}
}
static getDerivedStateFromProps(nextProps) {
return {
isLoading: nextProps.isLoading
};
}
render() {
return (
<Modal
transparent={true}
animationType={'none'}
visible={this.state.isLoading}
style={{ zIndex: 1100 }}
onRequestClose={() => { }}>
<View style={styles.modalBackground}>
<View style={styles.activityIndicatorWrapper}>
<ActivityIndicator animating={this.state.isLoading} color="black" />
{/* If you want to image set source here */}
{/* <Image
source={require('../assets/images/loader.gif')}
style={{ height: 80, width: 80 }}
resizeMode="contain"
resizeMethod="resize"
/> */}
</View>
</View>
</Modal>
)
}
}
const styles = StyleSheet.create({
modalBackground: {
flex: 1,
alignItems: 'center',
flexDirection: 'column',
justifyContent: 'space-around',
backgroundColor: '#rgba(0, 0, 0, 0.5)',
zIndex: 1000
},
activityIndicatorWrapper: {
backgroundColor: '#FFFFFF',
height: 100,
width: 100,
borderRadius: 10,
display: 'flex',
alignItems: 'center',
justifyContent: 'space-around'
}
});
export default Loader
Now you can use it when you have to display loading indicator as below :
<Loader isLoading={this.state.isLoading} />
import {Â ActivityIndicator } from 'react-native';
export default class LoginScreen extends Component {
constructor(props) {
super(props);
this.state = {
spinner : true
}
}
render() {
return (
<View style={{flex : 1, justifyContent: 'center', alignItems: 'center',}}>
{
this.state.spinner &&
<ActivityIndicator color={'#fff'} />
}
</View>
)
}
}
So you can show the SPinner for suppose when you have to load an API or something and when you get the response of api, you can set spinner loading value to false.
For eg :
import {View, ActivityIndicator } from 'react-native';
export default class MainScreen extends React.Component {
constructor(props) {
super(props);
this.state = {
spinner : true
}
}
componentDidMount(){
this.loadApi();
}
loadApi = async() => {
let result = axios.get('url').then((data) =>{
this.setState({spinner:false});
}
).catch((err) => this.setState({spinner:false})
}
render() {
return (
<View style={{flex : 1, justifyContent: 'center', alignItems: 'center',}}>
{
this.state.spinner? <ActivityIndicator color={'#fff'} />:<View><Text>Data loaded</Text></View>
}
</View>
)
}
}
you have to use ActivityIndicator you can have to load this activityindicator before getting data from the server , you have to check below code hope you will understand
import React, {useEffect, useState} from 'react';
import {ActivityIndicator, View, Dimensions} from 'react-native';
import HomeScreen from './Home';
const DataViewer = () => {
const [data, setData] = useState([]);
const {height, width} = Dimensions.get('window');
useEffect(() => {
fetch('http://example.com/movies.json')
.then(response => {
return response.json();
})
.then(myJson => {
setData(myJson);
});
});
return data.length > 0 ? (
<HomeScreen data={data} />
) : (
<View
style={{justifyContent: 'center', alignItems: 'center', height, width}}>
<ActivityIndicator size="large" color="#0000ff" />
</View>
);
};
export default DataViewer;
You can use the Activity indicator as the default loading animation. But you can also use Lottie files to implement custom loading screen animation on your project by installing npm i lottie-react-native or yarn add lottie-react-native
Here is the App.js
import React, { Component } from 'react';
import { Platform, StyleSheet, Text, View } from 'react-native';
import MovieList from './MovieList';
export default class App extends Component {
render() {
return (
<View style={styles.container}>
<MovieList />
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
alignItems: 'center',
backgroundColor: '#F5FCFF',
}
});
Here is the MoveList.js
import React, { Component } from 'react';
import { Platform, StyleSheet, FlatList, ActivityIndicator, Text, View } from 'react-native';
export default class MovieList extends Component {
constructor(props){
super(props);
this.state ={ isLoading: true}
}
componentDidMount() {
console.log("componentDidMount")
return fetch('https://facebook.github.io/react-native/movies.json')
.then((response) => response.json())
.then((responseJson) => {
// console.log("responseJson: " + JSON.stringify(responseJson))
this.setState({
isLoading: false,
dataSource: responseJson.movies,
}, function(){
});
})
.catch((error) =>{
console.error(error);
});
}
render(){
if(this.state.isLoading){
return(
<View style={{flex: 1, padding: 20}}>
<ActivityIndicator/>
</View>
)
}
return(
<View style={styles.container}>
<FlatList
data={this.state.dataSource}
renderItem={({item}) => <Text>{item.title}, {item.releaseYear}</Text>}
keyExtractor={({id}, index) => id}
/>
<MovieList name='Valeera' />
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
alignItems: 'center',
backgroundColor: '#F5FCFF',
}
});
The code for downloading the movie is from the official getting started tutorial networking, the only differences is that I put the code in a new js file called MovieList and include it as a component in the App.js
With the above code, the componentDidMount is being called none stop, and printing the movie list indefinitely, and eventually the app will crash.
Isn't the componentDidMount supposed to be called only once? What's causing it to be called indefinitely? What did I do wrong in the above code?
You are having your component MovieList embedded in the render-method of the component itself. This is creating the endless loop. Probably you only need to remove it there as your FlatList seems complete.
I'm trying to render a Flatlist that contains a store name. Upon clicking the store name, more information about the store should be displayed.
I attempted to change state and then use
{this.renderMoreDetails(item) && this.state.moreDetailsShown}
to get the additional information to appear. However, it was clear via console.log that state was only changed after a second button press.
From what I read in this article 1 and this article 2 it seemed as though I needed a callback function as an additional parameter to my setState().
I tried adding a callback function(probably incorrect, but I'm extremely lost at this point) and only got more errors.
I know that I have access to all of the data from renderItem inside FlatList. How do I make it appear upon click?
import React, { Component } from 'react';
import {
View,
FlatList,
Text,
TouchableWithoutFeedback,
ListView,
ScrollView
} from 'react-native'
import { NavigationActions } from 'react-navigation';
import { Header, Card, CardSection } from '../common';
import Config from '../Config';
export default class Costco extends Component<Props> {
constructor(props) {
super(props);
this.state = {
stores: [],
selectedItem: {id: null},
};
}
componentWillMount() {
const obj = Config.costcoThree;
const costcoArr = Object.values(obj);
this.setState({
stores: costcoArr,
})
}
renderListOfStores() {
return <FlatList
data={this.state.stores}
renderItem={ ({item}) => this.singleStore(item)}
keyExtractor={(item) => item.id}
extraData={this.state.selectedItem} />
}
singleStore(item) {
console.log(this.state.selectedItem.id)
return item.id === this.state.selectedItem.id ?
<TouchableWithoutFeedback
onPress={() => this.selectStore(item)}
>
<View>
<Text>{item.branchName}</Text>
<Text>Opening Time {item.openingTime}</Text>
<Text>Closing Time {item.closingTime}</Text>
<Text>Address {item.dongAddKor}</Text>
</View>
</TouchableWithoutFeedback>
:
<TouchableWithoutFeedback>
<View>
<Text>{item.branchName}</Text>
<Text>Only showing second part</Text>
</View>
</TouchableWithoutFeedback>
}
selectStore(item) {
this.setState({selectedItem: item});
console.log('repssed');
}
render() {
return(
<ScrollView>
<Header headerText="Costco"/>
<Text>hello</Text>
{this.renderListOfStores()}
</ScrollView>
)
}
}
as a workaround you can have a state that maintain your selected item to expand(or something like another view) and then you can use some conditions to work for render your flat list data.
Consider the below code and let me know if you need some more clarification.
import React, { Component } from 'react';
import {
Platform,
StyleSheet,
Text,FlatList,TouchableNativeFeedback,
View
} from 'react-native';
export default class App extends Component<Props> {
constructor(props) {
super(props);
this.state = {
response: [],
selectedItem: {id: null},
};
}
userListLayout() {
const {response} = this.state;
return <FlatList data={response} renderItem={ ({item}) => this.singleUserLayout(item)} keyExtractor={(item) => item.email} extraData={this.state.selectedItem} />
}
singleUserLayout(item) {
return item.id == this.state.selectedItem.id ?
<TouchableNativeFeedback onPress={() => this.userSelected(item)}>
<View style={{flex:1, borderColor: 'black', borderWidth: 1}}>
<Text style={{padding: 10, fontSize: 25}}>{item.email}</Text>
<Text style={{padding: 10,fontSize: 20}}>{item.name}</Text>
</View>
</TouchableNativeFeedback>
: <TouchableNativeFeedback onPress={() => this.userSelected(item)}><Text style={{padding: 10,fontSize: 20}}>{item.email}</Text></TouchableNativeFeedback>
}
userSelected(item) {
console.log(item)
this.setState({selectedItem: item})
}
componentDidMount() {
fetch("https://jsonplaceholder.typicode.com/users")
.then(data => data.json())
.then(response => this.setState({response}))
}
render() {
return (
<View style={styles.container}>
<Text style={styles.welcome}>HI THERE</Text>
{this.userListLayout()}
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
backgroundColor: '#F5FCFF',
},
welcome: {
fontSize: 20,
textAlign: 'center',
margin: 10,
},
instructions: {
textAlign: 'center',
color: '#333333',
marginBottom: 5,
},
});