Develop Reference

Displaying a Image from the Camera

I am relatively new to React-Native and mobile app development. I am trying to create a clone of Instagram. And in the post screen what I do is I have a button Camera and once I click on it, that should take me to CameraView screen. And in the CameraView screen I will take a picture using expo-camera and save the picture in a variable. So here, I want to export the picture and then import it in my Post screen, so that the user can have a preview of what the picture looks like before uploading. And another thing to note is that, the Post screen will by default have a Placeholder image and once the image is taken the placeholder image has to be replaced with the image.
I tried this code but it didnt work.
My Post screen :-
import { View, Text, Image, TextInput } from 'react-native';
import React, { useState, useEffect } from 'react'
import * as Yup from 'yup';
import { Formik } from 'formik'
import { Button, Divider } from 'react-native-elements';
import { useNavigation } from '#react-navigation/native';
import CameraView, { takePicture } from '../../screens/CameraView';
const PLACEHOLDER_IMG = require('../../assets/defImg.png')
const uploadPostSchema = Yup.object().shape({
caption: Yup.string().max(2200, 'Caption cannot exceed character limit.')
})
const FormikPostUploader = ({route}) => {
const [thumbnailUrl, setThumbnailUrl] = useState(PLACEHOLDER_IMG)
const navigation = useNavigation()
const handleCameraPress = () => {
UserImage = takePicture()
setThumbnailUrl(UserImage)
navigation.navigate('CameraView')
}
return (
<Formik
initialValues={{ imageUrl: '', caption:'' }}
onSubmit={(values) => console.log(values)}
validationSchema={uploadPostSchema}
validateOnMount={true}>
{({
handleBlur,
handleChange,
handleSubmit,
values,
errors,
isvalid
}) => (
<>
<View style={{ margin: 20, justifyContent: 'space-between', flexDirection: 'row' }}>
<Image source={thumbnailUrl} />
<View style={{ flex: 1, margin: 15 }}>
<TextInput
placeholder='Write a caption...'
placeholderTextColor='gray'
multiline={true}
style={{ color: 'white', fontSize: 17 }}
onChangeText={handleChange('caption')}
onBlur={handleBlur('caption')}
value={values.caption}
/>
</View>
</View>
<Divider width={0.5} orientation='vertical'/>
<View style={{ alignItems: 'center', marginTop: 15 }}>
<Text style={{ fontSize: 18, fontWeight: 'bold', color: 'white' }}>Choose Image</Text>
</View>
<View style={{ justifyContent: 'space-between', flexDirection: 'column', margin: 20 }}>
<View style={{ justifyContent: 'space-between', flexDirection: 'row', margin: 30 }}>
<Button title='Camera' onPress={handleCameraPress}/>
<Button title='Gallery' onPress={() => navigation.navigate('GalleryView')} />
</View>
<Button onPress={handleSubmit} title='Post' disabled={isvalid} />
</View>
</>
)}
</Formik>
)
}
export default FormikPostUploader
And my CameraView screen :-
import { View, Text, Image, StyleSheet, Button } from 'react-native'
import React, {useState, useEffect} from 'react'
import { Camera } from 'expo-camera'
import { TouchableOpacity } from 'react-native'
import { useNavigation } from '#react-navigation/native'
import { PLACEHOLDER_IMG } from '../components/newPost/FormikPostUploader'
export const takePicture = async(camera) => {
const data = await camera.takePictureAsync(null)
return data.uri
}
const Header = () =>{
const navigation = useNavigation()
return (
<View style = {styles.headerContainer}>
<TouchableOpacity style = {{marginBottom:15}} onPress={() => navigation.goBack()}>
<Image source = {require('../assets/back.png')} style = {{width:35, height:35, margin:20}}/>
</TouchableOpacity>
<Text style={{color:'white', fontWeight: '700', fontSize:20, marginRight: 25, marginTop:35, marginBottom:15}}>New Post</Text>
<Text> </Text>
</View>
)
}
const CameraView = () => {
const UserImage = takePicture()
const navigation = useNavigation()
const [hasCameraPermission, setHasCameraPermission] = useState(null)
const [thumbnailUrl, setThumbnailUrl] = useState(PLACEHOLDER_IMG)
const [camera, setCamera] = useState(null)
const [type, setType] = useState(Camera.Constants.Type.back)
const captureImage = async () => {
if (camera) {
const UserImage = await takePicture(camera)
setThumbnailUrl(UserImage)
}
}
useEffect(() => {
(async() => {
const cameraStatus = await Camera.requestCameraPermissionsAsync()
setHasCameraPermission(cameraStatus.status === 'granted')})()},
[])
if (hasCameraPermission === null) {
return <View/>
}
if (hasCameraPermission === false){
return <Text>Enable access for Camera to proceed</Text>
}
return (
<View style={{ flex: 1, backgroundColor: 'black'}}>
<Header/>
<Camera
ref = {ref => setCamera(ref)}
style={styles.fixedRatio}
type={type}
ratio={'1:1'}/>
<View style = {styles.cameraContainer}>
<TouchableOpacity onPress={() => {setType(type === Camera.Constants.Type.back ? Camera.Constants.Type.front : Camera.Constants.Type.back)}}>
<Image source={require('../assets/turn-camera.png')} style = {{width:70, height:70, margin: 15}}/>
</TouchableOpacity>
<TouchableOpacity onPress={() => {captureImage(), navigation.goBack(), console.log(UserImage)}}>
<Image source={require('../assets/camera-shutter.png')} style = {{width:70, height:70, marginRight:60}}/>
</TouchableOpacity>
</View>
</View>
)
}
const styles = StyleSheet.create({
cameraContainer: {
flex:0.15,
backgroundColor: 'black',
flexDirection:'row',
justifyContent: 'space-between',
alignItems: 'center',
},
fixedRatio: {
flex:0.99,
aspectRatio:0.9
},
headerContainer: {
flexDirection: 'row',
justifyContent: 'space-between',
alignItems: 'center',
backgroundColor:'black'
},
icon: {
width:25,
height: 25,
marginHorizontal:15,
marginTop:30,
},
iconContainer: {
flexDirection:'row',
justifyContent: 'space-between',
height:50,
},
}
)
export default CameraView
Am I doing anything wrong. Can you help me fix this. Thanks in advance!

React Native Flatlist element onPress not fired until List rendering is complete

I have a FlatList that receives (immutable) data of max. 50 elements and it renders in each list item Svg using react-native-svg.
Parts of the graphics are wrapped with a Pressable component for selecting the element.
Now the problem is, that I can't select any of the elements, until the FlatList went through all 50 items.
What I don't get is, that the offscreen items aren't even rendered, it's just the containers. Once it's all rendered, I can click the elements, the ripple effect shows and the event is fired.
Specs:
Expo # 46.0.0
React Native # 0.69.6
React # 18.0.0
Running with android via expo start --no-dev --minify then open in Expo Go
Reproduction:
import React, { useEffect, useState } from 'react'
import { FlatList } from 'react-native'
import { Foo } from '/path/to/Foo'
import { Bar } from '/path/to/Bar'
export const Overview = props => {
const [data, setData] = useState(null)
// 1. fetching data
useEffect(() => {
// load data from api
const loaded = [{ id: 0, type: 'foo' }, { id: 1, type: 'bar' }] // make a list of ~50 here
setData(loaded)
}, [])
if (!data?.length) {
return null
}
// 2. render list item
const onPressed = () => console.debug('pressed')
const renderListItem = ({ index, item }) => {
if (item.type === 'foo') {
return (<Foo key={`foo-${index}`} onPressed={onPressed} />)
}
if (item.type === 'bar') {
return (<Foo key={`bar-${index}`} onPressed={onPressed} />)
}
return null
}
// at this point data exists but will not be changed anymore
// so theoretically there should be no re-render
return (
<FlatList
data={data}
renderItem={renderListItem}
inverted={true}
decelerationRate="fast"
disableIntervalMomentum={true}
removeClippedSubviews={true}
persistentScrollbar={true}
keyExtractor={flatListKeyExtractor}
initialNumToRender={10}
maxToRenderPerBatch={10}
updateCellsBatchingPeriod={100}
getItemLayout={flatListGetItemLayout}
/>
)
}
}
// optimized functions
const flatListKeyExtractor = (item) => item.id
const flatListGetItemLayout = (data, index) => {
const entry = data[index]
const length = entry && ['foo', 'bar'].includes(entry.type)
? 110
: 59
return { length, offset: length * index, index }
}
Svg component, only Foo is shown, since Bar is structurally similar and the issue affects both:
import React from 'react'
import Svg, { G, Circle } from 'react-native-svg'
const radius = 25
const size = radius * 2
// this is a very simplified example,
// rendering a pressable circle
const FooSvg = props => {
return (
<Pressable
android_ripple={rippleConfig}
pressRetentionOffset={0}
hitSlop={0}
onPress={props.onPress}
>
<Svg
style={props.style}
width={size}
height={size}
viewBox={`0 0 ${radius * 2} ${radius * 2}`}
>
<G>
<Circle
cx='50%'
cy='50%'
stroke='black'
strokeWidth='2'
r={radius}
fill='red'
/>
</G>
</Svg>
</Pressable>
)
}
const rippleConfig = {
radius: 50,
borderless: true,
color: '#00ff00'
}
// pure component
export const Foo = React.memo(FooSvg)
The rendering performance itself is quite good, however I can't understand, why I need to wait up to two seconds, until I can press the circles, allthough they have already been rendered.
Any help is greatly appreciated.
Edit
When scrolling the list very fast, I get:
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. {"contentLength": 4740, "dt": 4156, "prevDt": 5142}
However, the Components are already memoized (PureComponent) and not very complex. There must be another issue.
Hardware
I cross tested with an iPad and there is none if the issues described. It seems to only occur on Android.

Please ignore grammatical mistakes.
This is the issue with FlatList. Flat list is not good for rendering a larger list at one like contact list. Flatlist is only good for getting data from API in church's like Facebook do. get 10 element from API and. then in the next call get 10 more.
To render. a larger number of items like contact list (more than 1000) or something like this please use https://bolan9999.github.io/react-native-largelist/#/en/
import React, {useRef, useState} from 'react';
import {
Image,
StyleSheet,
Text,
TextInput,
TouchableOpacity,
View,
} from 'react-native';
import {LargeList} from 'react-native-largelist-v3';
import Modal from 'react-native-modal';
import {widthPercentageToDP as wp} from 'react-native-responsive-screen';
import FontAwesome from 'react-native-vector-icons/FontAwesome';
import fonts from '../constants/fonts';
import {moderateScale} from '../constants/scaling';
import colors from '../constants/theme';
import countries from '../Data/larger_countries.json';
const CountrySelectionModal = ({visible, setDefaultCountry, setVisible}) => {
const pressable = useRef(true);
const [country_data, setCountryData] = useState(countries);
const [search_text, setSearchText] = useState('');
const onScrollStart = () => {
if (pressable.current) {
pressable.current = false;
}
};
const onScrollEnd = () => {
if (!pressable.current) {
setTimeout(() => {
pressable.current = true;
}, 100);
}
};
const _renderHeader = () => {
return (
<View style={styles.headermainView}>
<View style={styles.headerTextBg}>
<Text style={styles.headerTitle}>Select your country</Text>
</View>
<View style={styles.headerInputBg}>
<TouchableOpacity
onPress={() => searchcountry(search_text)}
style={styles.headericonBg}>
<FontAwesome
name="search"
size={moderateScale(20)}
color={colors.textColor}
/>
</TouchableOpacity>
<TextInput
placeholder="Select country by name"
value={search_text}
placeholderTextColor={colors.textColor}
style={styles.headerTextInput}
onChangeText={text => searchcountry(text)}
/>
</View>
</View>
);
};
const _renderEmpty = () => {
return (
<View
style={{
height: moderateScale(50),
backgroundColor: colors.white,
flex: 1,
justifyContent: 'center',
}}>
<Text style={styles.notFoundText}>No Result Found</Text>
</View>
);
};
const _renderItem = ({section: section, row: row}) => {
const country = country_data[section].items[row];
return (
<TouchableOpacity
activeOpacity={0.95}
onPress={() => {
setDefaultCountry(country),
setSearchText(''),
setCountryData(countries),
setVisible(false);
}}
style={styles.renderItemMainView}>
<View style={styles.FlagNameView}>
<Image
source={{
uri: `https://zoobiapps.com/country_flags/${country.code.toLowerCase()}.png`,
}}
style={styles.imgView}
/>
<Text numberOfLines={1} ellipsizeMode="tail" style={styles.text}>
{country.name}
</Text>
</View>
<Text style={{...styles.text, marginRight: wp(5), textAlign: 'right'}}>
(+{country.callingCode})
</Text>
</TouchableOpacity>
);
};
const searchcountry = text => {
setSearchText(text);
const items = countries[0].items.filter(row => {
const result = `${row.code}${row.name.toUpperCase()}`;
const txt = text.toUpperCase();
return result.indexOf(txt) > -1;
});
setCountryData([{header: 'countries', items: items}]);
};
return (
<Modal
style={styles.modalStyle}
animationIn={'slideInUp'}
animationOut={'slideOutDown'}
animationInTiming={1000}
backdropOpacity={0.3}
animationOutTiming={700}
hideModalContentWhileAnimating={true}
backdropTransitionInTiming={500}
backdropTransitionOutTiming={700}
useNativeDriver={true}
isVisible={visible}
onBackdropPress={() => {
setVisible(false);
}}
onBackButtonPress={() => {
setVisible(false);
}}>
<LargeList
showsHorizontalScrollIndicator={false}
style={{flex: 1, padding: moderateScale(10)}}
onMomentumScrollBegin={onScrollStart}
onMomentumScrollEnd={onScrollEnd}
contentStyle={{backgroundColor: '#fff'}}
showsVerticalScrollIndicator={false}
heightForIndexPath={() => moderateScale(49)}
renderIndexPath={_renderItem}
data={country_data}
bounces={false}
renderEmpty={_renderEmpty}
renderHeader={_renderHeader}
headerStickyEnabled={true}
initialContentOffset={{x: 0, y: 600}}
/>
</Modal>
);
};
export default CountrySelectionModal;
const styles = StyleSheet.create({
modalStyle: {
margin: moderateScale(15),
borderRadius: moderateScale(10),
overflow: 'hidden',
backgroundColor: '#fff',
marginVertical: moderateScale(60),
justifyContent: 'center',
},
headermainView: {
height: moderateScale(105),
backgroundColor: '#fff',
},
headerTextBg: {
height: moderateScale(50),
justifyContent: 'center',
alignItems: 'center',
backgroundColor: '#fff',
},
headerTitle: {
textAlign: 'center',
fontFamily: fonts.Bold,
fontSize: moderateScale(16),
color: colors.textColor,
textAlignVertical: 'center',
},
headerInputBg: {
height: moderateScale(40),
borderRadius: moderateScale(30),
overflow: 'hidden',
justifyContent: 'center',
alignItems: 'center',
paddingHorizontal: moderateScale(10),
backgroundColor: colors.inputbgColor,
flexDirection: 'row',
},
headericonBg: {
backgroundColor: colors.inputbgColor,
alignItems: 'center',
justifyContent: 'center',
width: moderateScale(40),
height: moderateScale(40),
},
headerTextInput: {
backgroundColor: colors.inputbgColor,
height: moderateScale(30),
flex: 1,
paddingTop: 0,
includeFontPadding: false,
fontFamily: fonts.Medium,
color: colors.textColor,
paddingBottom: 0,
paddingHorizontal: 0,
},
notFoundText: {
fontFamily: fonts.Medium,
textAlign: 'center',
fontSize: moderateScale(14),
textAlignVertical: 'center',
color: colors.textColor,
},
renderItemMainView: {
backgroundColor: colors.white,
flexDirection: 'row',
alignSelf: 'center',
height: moderateScale(43),
alignItems: 'center',
justifyContent: 'space-between',
width: wp(100) - moderateScale(30),
},
FlagNameView: {
flexDirection: 'row',
justifyContent: 'center',
paddingLeft: moderateScale(12),
alignItems: 'center',
},
imgView: {
height: moderateScale(30),
width: moderateScale(30),
marginRight: moderateScale(10),
borderRadius: moderateScale(30),
},
text: {
fontSize: moderateScale(13),
color: colors.textColor,
marginLeft: 1,
fontFamily: fonts.Medium,
},
});

tabBarOptions not applied to project (React Native)

I am creating a small app that has a to-do list and a calendar. At the bottom is a bottom tab navigator. Everything works and is functional, however, when I try to add style: {} inside tabBarOptions it isn't being applied. Changing activeTintColor, inactiveTintColor and labelStyle works just fine.
I tried to create a stylesheet and replace everything inside tabBarOptions, but that didn't work. My main goal is to simply create a slightly larger bar along the bottom of the screen. I don't even want a crazy custom navigation bar, just slightly larger so I can make the items inside a little bigger.
MainContainer Class:
import React from 'react';
import {StyleSheet} from 'react-native';
import {NavigationContainer} from '#react-navigation/native';
import {createBottomTabNavigator} from '#react-navigation/bottom-tabs';
import Ionicons from 'react-native-vector-icons/Ionicons'
//screens
import Calendar from './screens/Calendar';
import ToDoList from './screens/ToDoList';
// Screen names
const calendarName = 'Calendar';
const ToDoListName = 'To Do List';
const Tab = createBottomTabNavigator();
export default function MainContainer() {
return (
<NavigationContainer>
<Tab.Navigator
tabBarOptions={{
activeTintColor: 'tomato',
inactiveTintColor: 'black',
labelStyle: {paddingBottom: 10, fontSize: 10},
style: {padding: 10, height: 70},
}}
initialRouteName={ToDoListName}
screenOptions={({route}) => ({
tabBarIcon: ({focused, color, size}) => {
let iconName;
let rn = route.name;
if (rn === ToDoListName) {
iconName = focused ? 'list' : 'list-outline'; //icons in package. Change later.
} else if (rn === calendarName) {
iconName = focused ? 'calendar' : 'calendar-outline'
}
return <Ionicons name={iconName} size={size} color={color}/>
},
})}>
<Tab.Screen name={ToDoListName} component={ToDoList}/>
<Tab.Screen name={calendarName} component={Calendar}/>
</Tab.Navigator>
</NavigationContainer>
)
}
For reference here is my ToDoList class
import { KeyboardAvoidingView, StyleSheet, Text, View, TextInput, TouchableOpacity, Platform, Keyboard } from 'react-native';
import Task from '../../components/Task';
import React, { useState } from 'react';
import { ScrollView } from 'react-native-web';
export default function ToDoList() {
const [task, setTask] = useState();
const [taskItems, setTaskItems] = useState([]);
const handleAddTask = () => {
Keyboard.dismiss();
setTaskItems([...taskItems, task])
setTask(null);
}
const completeTask = (index) => {
let itemsCopy = [...taskItems];
itemsCopy.splice(index, 1);
setTaskItems(itemsCopy)
}
return (
<View style={styles.container}>
{/* Scroll View when list gets longer than page */}
<ScrollView contentContainerStyle={{
flexGrow: 1
}} keyboardShouldPersistTaps='handled'>
{/*Today's Tasks */}
<View style={styles.tasksWrapper}>
<Text style={styles.sectionTitle}>Today's Tasks</Text>
<View style={styles.items}>
{/* This is where the tasks will go*/}
{
taskItems.map((item, index) => {
return (
<TouchableOpacity key={index} onPress={() => completeTask(index)}>
<Task text={item} />
</TouchableOpacity>
)
})
}
</View>
</View>
</ScrollView>
{/* Write a task section */}
{/* Uses a keyboard avoiding view which ensures the keyboard does not cover the items on screen */}
<KeyboardAvoidingView
behavior={Platform.OS === "ios" ? "padding" : "height"}
style={styles.writeTaskWrapper}>
<TextInput style={styles.input} placeholder={'Write a task'} value={task} onChangeText={text => setTask(text)} />
<TouchableOpacity onPress={() => handleAddTask()}>
<View style={styles.addWrapper}>
<Text style={styles.addText}>+</Text>
</View>
</TouchableOpacity>
</KeyboardAvoidingView>
</View>
);
}
const styles = StyleSheet.create({
container: {
flex: 1,
backgroundColor: '#E8EAED',
},
tasksWrapper: {
paddingTop: 20,
paddingHorizontal: 20,
},
sectionTitle: {
fontSize: 24,
fontWeight: 'bold',
},
items: {
marginTop: 30,
},
writeTaskWrapper: {
position: 'absolute',
bottom: 20,
paddingLeft: 10,
paddingRight: 10,
width: '100%',
flexDirection: 'row',
justifyContent: 'space-between',
alignItems: 'center'
},
input: {
paddingVertical: 15,
width: 250,
paddingHorizontal: 15,
backgroundColor: '#FFF',
borderRadius: 60,
borderColor: '#C0C0C0',
borderWidth: 1,
},
addWrapper: {
width: 60,
height: 60,
backgroundColor: '#FFF',
borderRadius: 60,
justifyContent: 'center',
alignItems: 'center',
borderColor: '#C0C0C0',
borderWidth: 1,
},
addText: {
},
});
And my Calendar class
import * as React from 'react';
import { View, Text } from 'react-native';
export default function Calendar(){
return(
<View>
<Text>Calendar Will go here</Text>
</View>
)
}
I made a Task component for the ToDoList. Not sure if you need it to solve this but I'll paste it here anyway.
import React from 'react';
import { View, Text, StyleSheet } from 'react-native';
import { TouchableOpacity } from 'react-native-web';
const Task = (props) => {
return (
<View style={styles.item}>
<View style={styles.itemLeft}>
<View style={styles.square}></View>
<Text style={styles.itemText}>{props.text}</Text>
</View>
<View style={styles.circular}></View>
</View>
)
}
const styles = StyleSheet.create({
item: {
backgroundColor: '#FFF',
padding: 15,
borderRadius: 10,
flexDirection: 'row',
alignItems: 'center',
justifyContent: 'space-between',
marginBottom: 20,
},
itemLeft: {
flexDirection: 'row',
alignItems: 'center',
flexWrap: 'wrap',
},
square: {
width: 24,
height: 24,
backgroundColor: '#55BCF6',
opacity: .4,
borderRadius: 5,
marginRight: 15,
},
itemText: {
maxWidth: '80%',
},
circular: {
width: 12,
height: 12,
borderColor: '#55BCF6',
borderWidth: 2,
borderRadius: 5
},
});
export default Task;

It sounds like you are looking for the tabBarStyle property. You should be able to rename style (which is not a supported prop of the tab navigator) to tabBarStyle.
Here's the spot in the docs that mentions this. https://reactnavigation.org/docs/bottom-tab-navigator#tabbarstyle

What I ended up doing to solve this was to put the styling inside the screenOptions. I didn't want to do this because I wanted to separate the styling from the logic, but it solved the problem for me. See code below:
export default function MainContainer() {
return (
<NavigationContainer>
<Tab.Navigator
initialRouteName={ToDoListName}
screenOptions={({route}) => ({
tabBarIcon: ({focused, color, size}) => {
let iconName;
let rn = route.name;
if (rn === ToDoListName) {
iconName = focused ? 'list' : 'list-outline'; //icons in package. Change later.
} else if (rn === calendarName) {
iconName = focused ? 'calendar' : 'calendar-outline'
}
return <Ionicons name={iconName} size={size} color={color}/>
},
activeTintColor: 'tomato',
inactiveTintColor: 'black',
tabBarShowLabel: false,
tabBarStyle: {padding: 10, height: 100, backgroundColor: 'black'},
})}>
<Tab.Screen name={ToDoListName} component={ToDoList}/>
<Tab.Screen name={calendarName} component={Calendar}/>
</Tab.Navigator>
</NavigationContainer>
)
}

How can I store the value of TextInput to local storage and get them when the app starts in react native?

I'm making a to-do list app. I need to store the input value locally or somewhere so that I can show them in the app even if the app is opened after closing once. Now when I'm closing the app and restarting all the previous values is being vanished. But I want to keep the previous data and If new data is given that will also be stored if I don't delete that manually. How can I solve this problem? I'm using expo.
Here is my code:
import React, { useState } from 'react';
import { View, Text, StyleSheet, Button, FlatList, TouchableOpacity, TextInput, ScrollView } from 'react-native';
import { MaterialIcons } from '#expo/vector-icons'
import Line from './Line';
function App() {
//storing data in array
const [initialElements, changeEl] = useState([
]);
const [value, setValue] = useState('')
const [idx, incr] = useState(1);
const [exampleState, setExampleState] = useState(initialElements);
//add button
const addElement = () => {
if (value != '') {
var newArray = [...initialElements, { id: idx, title: value }];
incr(idx + 1);
setExampleState(newArray);
changeEl(newArray);
}
}
//delete button
const delElement = (id) => {
let newArray = initialElements.filter(function (item) {
return item.id !== id
})
setExampleState(newArray);
changeEl(newArray);
}
//showing item
const Item = ({ title, id }) => (
<View style={{ flex: 1, flexDirection: 'row', alignItems: 'center' }}>
<View style={{ borderWidth: 2, margin: 5, flex: 1, padding: 10, borderRadius: 10 }}>
<TouchableOpacity onPress={() => { alert(title) }}>
<Text >{title}</Text>
</TouchableOpacity>
</View>
<TouchableOpacity onPress={() => delElement(id)}>
<MaterialIcons name='delete' size={24} />
</TouchableOpacity>
</View>
);
//calling item for render
const renderItem = ({ item }) => {
<Item title={item.title} id={item.id} />
}
return (
<View style={styles.container}>
<View style={{ alignItems: 'center', marginBottom: 10 }}>
<Text style={{ fontSize: 20, fontWeight: '500' }}> To <Text style={{ color: 'skyblue', fontWeight: '900' }}>Do</Text> List</Text>
<Line />
</View>
<View>
<TextInput onChangeText={text => setValue(text)} placeholder="Enter to Todo" style={{ borderWidth: 2, borderRadius: 10, backgroundColor: 'skyblue', height: 40, paddingLeft: 10, borderColor: 'black' }}></TextInput>
</View>
<View style={{ alignItems: 'center' }}>
<TouchableOpacity onPress={() => addElement()} style={{ marginTop: 10 }}>
<View style={{ backgroundColor: 'black', width: 70, height: 40, justifyContent: 'center', borderRadius: 10 }}>
<Text style={{ color: 'white', textAlign: 'center' }}>Add</Text>
</View>
</TouchableOpacity>
</View>
<FlatList
style={{ borderWidth: 2, padding: 10, flex: 1, backgroundColor: '#EEDDD0', marginTop: 10 }}
data={exampleState}
renderItem={renderItem}
keyExtractor={item => item.id.toString()
}
/>
</View>
);
}
const styles = StyleSheet.create({
container: {
flex: 1,
marginTop: 20,
margin: 5,
}
})
export default App;

React Native provides a local storage option called AsyncStorage. You might use asyncstorage to save the data locally on the device and get that data inside useEffect() hook on startup.
You can find more about AsyncStorage here.
Although this is deprecated and now community package " #react-native-async-storage/async-storage " is used. The implementation remains the same.

How can i get back my data list after searching by words?

i use Flatlist and search by words on renderHeader() function. I can filter but when i delete letters, i couldn't get main list again. I think there is a logic problem but i couln't find after trying something...
i've got a new one when i fixed problem. I tried to fix but i couldn't do that, i should put the problem in front of experts :)
import React, {Component, useState} from 'react'
import {
Text,
StyleSheet,
View,
FlatList,
SafeAreaView,
ScrollView,
Image,
TextInput,
} from 'react-native'
import data from '../../data'
const Flatlistexample = () => {
//main list state
let [list, setList] = useState(data);
//search state
const [search, setSearch] = useState('');
//search filter
searchFilter = text => {
// onChangeText
const newData = list.filter(item => {
const listItem = `${item.name.toLowerCase()} ${item.company.toLowerCase()}`
return listItem.indexOf(text.toLowerCase()) > -1;
})
setList(newData)
}
//search function
renderHeader = () =>{
return (
<View style={styles.seachContainer}>
<TextInput
style={styles.textInput}
placeholder={'Search...'}
value={search}
onChangeText={text => {
//setStates
searchFilter(text)
setSearch(text)
}}></TextInput>
<Text
style={{
alignItems: 'flex-start',
color: 'black',
fontSize: 22,
}}>
{search}
</Text>
</View>
)
}
return (
<SafeAreaView
style={{
flex: 1,
}}>
<FlatList
data={list}
renderItem={({item, index}) => {
return (
<ScrollView>
<SafeAreaView
style={[
styles.container,
{backgroundColor: index % 2 === 0 ? '#fafafa' : '#bbb'},
]}>
<Image style={styles.profile} source={{uri: item.picture}} />
<View style={styles.rightside}>
<Text style={styles.name}>{item.name}</Text>
<Text style={styles.company}>{item.company}</Text>
</View>
</SafeAreaView>
</ScrollView>
)
}}
keyExtractor={item => item._id}
//called search function
ListHeaderComponent={renderHeader()}
/>
</SafeAreaView>
)
}
export default Flatlistexample
const styles = StyleSheet.create({
container: {
flexDirection: 'row',
alignItems: 'center',
borderBottomWidth: 1,
borderColor: 'gray',
},
profile: {
width: 50,
height: 50,
borderRadius: 25,
marginLeft: 10,
},
rightside: {
marginLeft: 20,
justifyContent: 'space-between',
marginVertical: 5,
},
name: {
fontSize: 22,
marginBottom: 10,
},
searchContainer: {
padding: 10,
borderWidth: 2,
borderColor: 'gray',
},
textInput: {
fontSize: 16,
backgroundColor: '#f9f9f9',
padding: 10,
},
})
Thanks for your help

Filter Data
onSearchText = (value) => {
this.setState({searchText: value})
if(value.trim() == "" || value == null){
this.setState({list: this.state.list}
} else {
let filter = this.state.list.fillter(data => {
// data fillter logic //
return data;
})
this.setState({filterData: filter})
}
Render FlatList
<FlatList
extradata={this.state}
data={searchText ? filterData : list}
/>

I fixed...
How?
My main data state is constant, i'm filtering on data list with filter state. So my data list doesn't change anytime.
import React, {Component, useState} from 'react'
import {
Text,
StyleSheet,
View,
FlatList,
SafeAreaView,
ScrollView,
Image,
TextInput,
} from 'react-native'
import data from '../../data'
const Flatlistexample = () => {
//main list state
let [list, setList] = useState(data)
//search state
const [search, setSearch] = useState('')
//filter state
const [updated, setUpdated] = useState(data)
//search filter
searchFilter = text => {
// onChangeText
if (text) {
const newData = list.filter(item => {
const listItem = `${item.name.toLowerCase()} ${item.company.toLowerCase()}`
return listItem.indexOf(text.toLowerCase()) > -1
})
setUpdated(newData)
}
//search function
renderHeader = () => {
return (
<View style={styles.seachContainer}>
<TextInput
style={styles.textInput}
placeholder={'Search...'}
value={search}
onChangeText={text => {
searchFilter(text)
setSearch(text)
}}></TextInput>
<Text
style={{
alignItems: 'flex-start',
color: 'black',
fontSize: 22,
}}>
{search}
</Text>
</View>
)
}
return (
<SafeAreaView
style={{
flex: 1,
}}>
<FlatList
//i'm showing filter state
data={updated}
renderItem={({item, index}) => {
return (
<ScrollView>
<SafeAreaView
style={[
styles.container,
{backgroundColor: index % 2 === 0 ? '#fafafa' : '#bbb'},
]}>
<Image style={styles.profile} source={{uri: item.picture}} />
<View style={styles.rightside}>
<Text style={styles.name}>{item.name}</Text>
<Text style={styles.company}>{item.company}</Text>
</View>
</SafeAreaView>
</ScrollView>
)
}}
keyExtractor={item => item._id}
//called search function
ListHeaderComponent={renderHeader()}
/>
</SafeAreaView>
)
}
export default Flatlistexample
const styles = StyleSheet.create({
container: {
flexDirection: 'row',
alignItems: 'center',
borderBottomWidth: 1,
borderColor: 'gray',
},
profile: {
width: 50,
height: 50,
borderRadius: 25,
marginLeft: 10,
},
rightside: {
marginLeft: 20,
justifyContent: 'space-between',
marginVertical: 5,
},
name: {
fontSize: 22,
marginBottom: 10,
},
searchContainer: {
padding: 10,
borderWidth: 2,
borderColor: 'gray',
},
textInput: {
fontSize: 16,
backgroundColor: '#f9f9f9',
padding: 10,
},
})
/*
else if(text.length > uzunluk){
setList(data)
const newData = list.filter(item => {
const listItem = `${item.name.toLowerCase()} ${item.company.toLowerCase()}`
return listItem.indexOf(text.toLowerCase()) > -1;
})
setList(newData)
}else if(text.length<uzunluk){
setList(data)
const newData = list.filter(item => {
const listItem = `${item.name.toLowerCase()} ${item.company.toLowerCase()}`
return listItem.indexOf(text.toLowerCase()) > -1;
})
setList(newData)
}
*/