Develop Reference

How to list items with the same id in Async Storage in React Native

I'm new to React native, I'm creating a online store app my problem is : when the person selects a repeated item it does not appear in the cart it just updates , I would like it to include and list in the cart this repeated item ... as I said I'm new to react native, but I believe the problem is in the listing and not in the register ...
Function add in cart in AddCart.js
const addToCart = async (id) => {
let itemArray = await AsyncStorage.getItem('cartItems');
itemArray = JSON.parse(itemArray);
if (itemArray) {
let array = itemArray;
array.push(id);
try {
await AsyncStorage.setItem('cartItems', JSON.stringify(array));
ToastAndroid.show(
'Item Added Successfully to cart',
ToastAndroid.SHORT,
);
navigation.navigate('Home');
} catch (error) {
return error;
}
} else {
let array = [];
array.push(id);
try {
await AsyncStorage.setItem('cartItems', JSON.stringify(array));
ToastAndroid.show(
'Item Added Successfully to cart',
ToastAndroid.SHORT,
);
navigation.navigate('Home');
} catch (error) {
return error;
}
}
};
MyCart.js
import React, {useState, useEffect} from 'react';
import {
View,
Text,
TouchableOpacity,
Image,
Alert
} from 'react-native';
import AsyncStorage from '#react-native-async-storage/async-storage';
const MyCart = ({navigation}) => {
const [product, setProduct] = useState();
useEffect(() => {
const unsubscribe = navigation.addListener('focus', () => {
getDataFromDB();
});
return unsubscribe;
}, [navigation]);
const getDataFromDB = async id =>{
let items = await AsyncStorage.getItem('cartItems');
items = JSON.parse(items);
if(items.length===0){
Alert.alert(
"Ops",
"The cart is empty",
[
{
text: "Ok",
onPress: () => navigation.navigate('Home'),
style: "cancel"
}
]
);
}else{
let productData = [];
if (items) {
Items.forEach(data => {
if (items.includes(data.id)) {
productData.push(data);
return;
}
});
setProduct(productData);
getTotal(productData);
} else {
setProduct(false);
getTotal(false);
}
}
};
const renderProducts = (data, index) => {
return (
<TouchableOpacity
key={data.key}
onPress={() => navigation.navigate('ProductInfo', {productID: data.id})}
style={{
width: '100%',
height: 100,
marginVertical: 6,
flexDirection: 'row',
alignItems: 'center',
}}>
<View
style={{
width: '30%',
height: 100,
padding: 14,
justifyContent: 'center',
alignItems: 'center',
backgroundColor: COLOURS.backgroundLight,
borderRadius: 10,
marginRight: 22,
}}>
<Image
source={data.productImage}
style={{
width: '100%',
height: '100%',
resizeMode: 'contain',
}}
/>
</View>
<View
style={{
flex: 1,
height: '100%',
justifyContent: 'space-around',
}}>
<View style={{}}>
<Text
style={{
fontSize: 14,
maxWidth: '100%',
color: COLOURS.black,
fontWeight: '600',
letterSpacing: 1,
}}>
{data.productName},
</Text>
<View
style={{
marginTop: 4,
flexDirection: 'row',
alignItems: 'center',
opacity: 0.6,
}}>
<Text
style={{
fontSize: 14,
fontWeight: '400',
maxWidth: '85%',
marginRight: 4,
}}>
R$ {data.productPrice2}.00 , {data.id}
</Text>
<Text>
</Text>
</View>
</View>
<View
style={{
flexDirection: 'row',
justifyContent: 'space-between',
alignItems: 'center',
}}>
<View
style={{
flexDirection: 'row',
alignItems: 'center',
}}>
<View
style={{
borderRadius: 100,
marginRight: 20,
padding: 4,
borderWidth: 1,
borderColor: COLOURS.backgroundMedium,
opacity: 0.5,
}}>
<MaterialCommunityIcons
name="minus"
style={{
fontSize: 16,
color: COLOURS.backgroundDark,
}}
/>
</View>
<Text>1</Text>
<View
style={{
borderRadius: 100,
marginLeft: 20,
padding: 4,
borderWidth: 1,
borderColor: COLOURS.backgroundMedium,
opacity: 0.5,
}}>
<MaterialCommunityIcons
name="plus"
style={{
fontSize: 16,
color: COLOURS.backgroundDark,
}}
/>
</View>
</View>
<TouchableOpacity onPress={() => removeItemFromCart(data.id)}>
<MaterialCommunityIcons
name="delete-outline"
style={{
fontSize: 16,
color: COLOURS.backgroundDark,
backgroundColor: COLOURS.backgroundLight,
padding: 8,
borderRadius: 100,
}}
/>
</TouchableOpacity>
</View>
</View>
</TouchableOpacity>
);
};
return (
<View> {product ? product.map(renderProducts) : null} </View>
);
};
export default MyCart;
I would be grateful to help me

ERROR : undefined is not an object (evaluation 'style.width')

Hello everyone I'm having trouble with component and I get an undefined error message.So my app has 2 screen,the first one has a list of imagebackgrounds and when you press on one of the images you get a description of that image on another screen.So on this second screen I get the image that I pressed on in an image component (not background).
The problem I'm having is that when I save I get the undefined error.
First screen component :
const MealItems = (props) => {
return (
<View style={styles.main}>
<TouchableOpacity onPress={props.onSelectMeal}>
<View>
<View style={{ ...styles.details, ...styles.maintitle }}>
<ImageBackground
//resizeMode={"center"}
source={{ uri: props.image }}
style={styles.imagebg}
>
<View style={styles.textContainer}>
<Text style={styles.title} numberOfLines={1}>
{props.title}
</Text>
</View>
</ImageBackground>
</View>
<View style={{ ...styles.details, ...styles.info }}>
<Text>{props.duration}</Text>
<Text>{props.complexity.toUpperCase()}</Text>
<Text>{props.affordability.toUpperCase()}</Text>
</View>
</View>
</TouchableOpacity>
</View>
);
};
styles = StyleSheet.create({
main: {
height: 200,
width: "100%",
backgroundColor: "#f5f5f5",
borderRadius: 20,
overflow: "hidden",
marginVertical: 10,
},
maintitle: {
height: "85%",
},
title: {
fontSize: 20,
color: "white",
textAlign: "center",
},
details: {
flexDirection: "row",
},
imagebg: {
width: "100%",
height: "100%",
},
info: {
backgroundColor: "gray",
paddingHorizontal: 10,
justifyContent: "space-between",
alignItems: "center",
height: "15%",
},
textContainer: {
paddingHorizontal: 12,
paddingVertical: 10,
backgroundColor: "rgba(0,0,0,0.3)",
},
});
export default MealItems;
***Second screen file:***
const howToCook = (props) => {
const availableMeals = useSelector((state) => state.Meals.filteredMeals);
const mealId = props.navigation.getParam("mealId");
const selectedMeal = availableMeals.find((meal) => mealId === meal.id);
return (
<ScrollView>
<Image source={{ uri: selectedMeal.imageUrl }} style={styles.image} />
<View style={styles.textDetail}>
<Text>{selectedMeal.duration}</Text>
<Text>{selectedMeal.complexity.toUpperCase()}</Text>
<Text>{selectedMeal.affordability.toUpperCase()}</Text>
</View>
<View style={styles.titlePlace}>
<Text style={styles.textTitle}>Ingredients</Text>
</View>

Trouble storing use input text in react native

I am trying to store the value of the color and the font size that the user has entered, but my program doesnt store the value, it changes it instantly when the user inputs text. I want it to change the font and background color when 'press me' is clicked. Here is what ive so far:
import React, { useState, useEffect } from 'react';
import { StyleSheet, Text, View, TextInput, Button, TouchableOpacity, Alert } from 'react-native';
function Input(props) {
return (
<TextInput
{...props}
style={{ height: 40, borderWidth: 1, padding: 20, paddingTop: 10, margin: 5 }}
editable
maxLength={40}
/>
);
}
export default function InputMultiline() {
const [mySize, setMySize] = useState('20');
const [myBGColor, setMyColor] = useState('yellow');
const colChange = () => {
setMyColor(myBGColor);
setMySize(mySize);
}
return (
<View
style={{
flex: 1,
alignItems: 'center',
justifyContent: 'center',
backgroundColor: myBGColor.toLowerCase(),
borderBottomColor: '#000000',
borderBottomWidth: 1,
}}>
<Text style={{ fontSize: Number(mySize) }}>Hello</Text>
<View>
<Input
multiline
numberOfLines={4}
value={myBGColor}
onChangeText={colText => setMyColor(colText)}
/></View>
<View>
<Input
multiline
numberOfLines={4}
value={mySize}
onChangeText={sizeText => setMySize(sizeText)}
/></View>
<View style={styles.fixToText}>
<TouchableOpacity>
<Button onPress={colChange}
title="Press Me!"
color="#841584" />
</TouchableOpacity>
</View>
</View>
);
}
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
marginHorizontal: 16,
},
title: {
textAlign: 'center',
marginVertical: 8,
fontSize: 20
},
fixToText: {
flexDirection: 'row',
justifyContent: 'space-between',
},
separator: {
marginVertical: 8,
borderBottomColor: '#737373',
borderBottomWidth: StyleSheet.hairlineWidth,
},
});
I have no clue how to change the font and background color together and click on 'press me'.

You should add 2 more states that will contain user's input:
export default function InputMultiline() {
const [mySize, setMySize] = useState('20');
const [myBGColor, setMyColor] = useState('yellow');
const [mySizeUserInput, setMySizeUserInput] = useState('20'); <---- ADDED
const [myBGColorUserInput, setMyColorUserInput] = useState('yellow'); <----- ADDED
const colChange = () => {
setMyColor(myBGColorUserInput); <----- CHANGED
setMySize(mySizeUserInput); <----- CHANGED
}
return (
<View
style={{
flex: 1,
alignItems: 'center',
justifyContent: 'center',
backgroundColor: myBGColor.toLowerCase(),
borderBottomColor: '#000000',
borderBottomWidth: 1,
}}>
<Text style={{ fontSize: Number(mySize) }}>Hello</Text>
<View>
<Input
multiline
numberOfLines={4}
value={myBGColor}
onChangeText={colText => setMyColorUserInput(colText)} <----- CHANGED
/></View>
<View>
<Input
multiline
numberOfLines={4}
value={mySize}
onChangeText={sizeText => setMySizeUserInput(sizeText)} <----- CHANGED
/></View>
<View style={styles.fixToText}>
<TouchableOpacity>
<Button onPress={colChange}
title="Press Me!"
color="#841584" />
</TouchableOpacity>
</View>
</View>
);
Se tu

I was able to reproduce the issue with your codes, in my case styles were broken so you can try to change the view by removing flex and adding height, like this:
<View style={{
alignItems: 'center',
justifyContent: 'center',
backgroundColor: myBGColor.toLowerCase(),
height: 100,
}}>

Why does it appear that react-native does not recognize the png in my directory?

I am trying to use an icon "ic_shuffle_white.png" and the image is clearly in my directory, so I am not sure why I am getting the "Unable to resolve..." error.
I restarted my Xcode after adding the pngs, imported Image from react-native, and there does not appear to be a syntax error.
I am following this guide: https://hackernoon.com/building-a-music-streaming-app-using-react-native-6d0878a13ba4
Is it because I am using expo? or is the guide too old?
Screenshot:
Code:
import React, { Component } from 'react';
import {
View,
Text,
StyleSheet,
Image,
TouchableOpacity,
} from 'react-native';
const Controls = ({
paused,
shuffleOn,
repeatOn,
onPressPlay,
onPressPause,
onBack,
onForward,
onPressShuffle,
onPressRepeat,
forwardDisabled,
}) => (
<View style={styles.container}>
<TouchableOpacity activeOpacity={0.0} onPress={onPressShuffle}>
<Image style={[styles.secondaryControl, shuffleOn ? [] : styles.off]}
source={require('../img/ic_shuffle_white.png')}/>
</TouchableOpacity>
<View style={{width: 40}} />
<TouchableOpacity onPress={onBack}>
<Image source={require('../img/ic_skip_previous_white_36pt.png')}/>
</TouchableOpacity>
<View style={{width: 20}} />
{!paused ?
<TouchableOpacity onPress={onPressPause}>
<View style={styles.playButton}>
<Image source={require('../img/ic_pause_white_48pt.png')}/>
</View>
</TouchableOpacity> :
<TouchableOpacity onPress={onPressPlay}>
<View style={styles.playButton}>
<Image source={require('../img/ic_play_arrow_white_48pt.png')}/>
</View>
</TouchableOpacity>
}
<View style={{width: 20}} />
<TouchableOpacity onPress={onForward}
disabled={forwardDisabled}>
<Image style={[forwardDisabled && {opacity: 0.3}]}
source={require('../img/ic_skip_next_white_36pt.png')}/>
</TouchableOpacity>
<View style={{width: 40}} />
<TouchableOpacity activeOpacity={0.0} onPress={onPressRepeat}>
<Image style={[styles.secondaryControl, repeatOn ? [] : styles.off]}
source={require('../img/ic_repeat_white.png')}/>
</TouchableOpacity>
</View>
);
export default Controls;
const styles = StyleSheet.create({
container: {
flexDirection: 'row',
alignItems: 'center',
justifyContent: 'center',
paddingTop: 8,
},
playButton: {
height: 72,
width: 72,
borderWidth: 1,
borderColor: 'white',
borderRadius: 72 / 2,
alignItems: 'center',
justifyContent: 'center',
},
secondaryControl: {
height: 18,
width: 18,
},
off: {
opacity: 0.30,
}
})

Change Button Color onPress (toggle functionality) React Native

hope all is well.
I seem to be having difficulty with a basic button functionality. All I need is the state of the class to change and the button style to change every-time the button is pressed. Unlike TouchableHighlight, I need to color change to stay until the button is pressed again (to go back to the original color).
I have tried to use SwitchIOS but it doesn't seem to be easily styled into a circular button, and therefore doesn't really work out. I am a novice so still learning and would greatly appreciate your help. Here is what I have so far:
'use strict';
var React = require('react-native');
var Dimensions = require('Dimensions');
var window = Dimensions.get('window');
var Icon = require('react-native-vector-icons/FontAwesome');
var {
AppRegistry,
StyleSheet,
Text,
View,
NavigatorIOS,
Image,
TouchableHighlight,
TextInput,
} = React;
class LS1 extends React.Component{
constructor(props){
super(props);
this.state = {
paleo: false,
vegan: false,
vegetarian: false,
nutfree: false,
dairyfree: false,
healthy: false,
glutenfree: false,
}
}
SkipLogin() {
var num = window.height/8.335;
console.log(num);
}
render() {
return (
<View style={styles.container}>
<Image source={require('image!LS1')} style={styles.bgImage}>
<Text style={styles.icontext}>Help us get to know your dietary lifestyle.</Text>
<View style={styles.container}>
<View style={{flex: 1, alignItems: 'center', flexDirection: 'row',justifyContent: 'center',marginTop:-20}}>
<TouchableHighlight underlayColor='rgba(73,182,77,1,0.9)' style={styles.bubblechoice}>
<Image style={styles.bubblechoice} source={require('image!vegan')}>
<View style={styles.overlay}>
<Text style={styles.choicetext}>Vegan</Text>
</View>
</Image>
</TouchableHighlight>
<TouchableHighlight underlayColor='rgba(73,182,77,1,0.6)' style={styles.bubblechoice} >
<Image style={styles.bubblechoice} source={require('image!paleo')}>
<View style={styles.overlay}>
<Text style={styles.choicetext}>Paleo</Text>
</View>
</Image>
</TouchableHighlight>
<TouchableHighlight underlayColor='rgba(73,182,77,1,0.6)' style={styles.bubblechoice} >
<Image style={styles.bubblechoice} source={require('image!nutfree')}>
<View style={styles.overlay}>
<Text style={styles.choicetext}>Nut-Free</Text>
</View>
</Image>
</TouchableHighlight>
<TouchableHighlight underlayColor='rgba(73,182,77,1,0.6)' style={styles.bubblechoice} >
<Image style={styles.bubblechoice} source={require('image!glutenfree')}>
<View style={styles.overlay}>
<Text style={styles.choicetext}>Gluten-Free</Text>
</View>
</Image>
</TouchableHighlight>
</View>
<View style={{flex: 1, alignItems: 'center', flexDirection: 'row',justifyContent: 'center',marginTop:-50}}>
<TouchableHighlight underlayColor='rgba(73,182,77,1,0.6)' style={styles.bubblechoice} >
<Image style={styles.bubblechoice} source={require('image!dairyfree')}>
<View style={styles.overlay}>
<Text style={styles.choicetext}>Dairy-Free</Text>
</View>
</Image>
</TouchableHighlight>
<TouchableHighlight underlayColor='rgba(73,182,77,1,0.6)' style={styles.bubblechoice} >
<Image style={styles.bubblechoice} source={require('image!vegetarian')}>
<View style={styles.overlay}>
<Text style={styles.choicetext}>Vegetarian</Text>
</View>
</Image>
</TouchableHighlight>
<TouchableHighlight underlayColor='rgba(73,182,77,1,1)' style={styles.bubblechoice} >
<Image style={styles.bubblechoice} source={require('image!healthy')}>
<View style={styles.overlay}>
<Text style={styles.choicetext}>Healthy</Text>
</View>
</Image>
</TouchableHighlight>
</View>
</View>
<Image source={require('image!nextbtn')} style={{resizeMode: 'contain', width:200, height:50, alignSelf: 'center', marginBottom: 50}}/>
<TouchableHighlight onPress={this.SkipLogin.bind(this)} underlayColor='transparent'>
<View style={{backgroundColor: 'transparent', alignItems: 'center', marginBottom: 8}}>
<Text>skip this step</Text>
</View>
</TouchableHighlight>
</Image>
</View>
);
}
};
var styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
alignItems: 'center',
backgroundColor: 'transparent'
},
bgImage: {
flex: 1,
width: window.width,
resizeMode: 'cover',
},
icontext: {
color: '#5d5d5d',
fontWeight: '400',
fontSize: 20,
backgroundColor: 'transparent',
paddingLeft: 10,
alignItems: 'center',
marginTop: window.height/2.2,
textAlign: 'center',
margin: 10,
},
bubblechoice_click: {
height: window.height/8.335,
borderRadius: (window.height/8.3350)/2,
marginRight: 2,
width: window.height/8.335,
},
bubblechoice: {
height: window.height/8.335,
borderRadius: (window.height/8.3350)/2,
marginRight: 2,
width: window.height/8.335,
},
row: {
flex: 1,
alignItems: 'center',
flexDirection: 'row',
justifyContent: 'center',
marginTop: -30,
},
choicetext: {
alignItems: 'center',
alignSelf: 'center',
color: 'white',
marginTop: 35,
fontWeight: '600',
marginLeft: -18,
fontSize: 14,
flex: 1,
textAlign: 'center'
},
overlay: {
backgroundColor:'rgba(80,94,104,0.7)',
height: 100,
width: 100,
alignItems:'center'
},
});
module.exports = LS1;
And here is a visual of what that produces:
Here's what the button should look like after being selected:

I think you should take a step back and do some basic React tutorials before digging too much into React Native - this is a fairly straightforward problem to solve :) Here's a solution for you:
'use strict';
var React = require('react-native');
var Dimensions = require('Dimensions');
var window = Dimensions.get('window');
var {
AppRegistry,
StyleSheet,
Text,
View,
NavigatorIOS,
Image,
TouchableHighlight,
TextInput,
} = React;
class ToggleButton extends React.Component {
render() {
return (
<TouchableHighlight underlayColor='rgba(73,182,77,1,0.9)' style={styles.bubblechoice} onPress={this.props.onPress}>
<Image style={styles.bubblechoice} source={{uri: 'https://facebook.github.io/react/img/logo_og.png'}}>
<View style={[styles.overlay, this.props.selected ? {backgroundColor: 'rgba(80,94,104,0)'} : {}]}>
<Text style={styles.choicetext}>{this.props.label}</Text>
</View>
</Image>
</TouchableHighlight>
);
}
}
class LS1 extends React.Component{
constructor(props){
super(props);
this.state = {
paleo: false,
vegan: false,
vegetarian: false,
}
}
updateChoice(type) {
let newState = {...this.state};
newState[type] = !newState[type];
this.setState(newState);
}
SkipLogin() {
var num = window.height/8.335;
console.log(num);
}
render() {
return (
<View style={styles.container}>
<View style={styles.bgImage}>
<Text style={styles.icontext}>Help us get to know your dietary lifestyle.</Text>
<View style={styles.container}>
<View style={{flex: 1, alignItems: 'center', flexDirection: 'row',justifyContent: 'center',marginTop:-20}}>
<ToggleButton label='Vegan' onPress={() => { this.updateChoice('vegan') }} selected={this.state.vegan} />
<ToggleButton label='Paleo' onPress={() => { this.updateChoice('paleo') }} selected={this.state.paleo} />
<ToggleButton label='Vegetarian' onPress={() => { this.updateChoice('vegetarian') }} selected={this.state.vegetarian} />
</View>
</View>
<TouchableHighlight onPress={this.SkipLogin.bind(this)} underlayColor='transparent'>
<View style={{backgroundColor: 'transparent', alignItems: 'center', marginBottom: 8}}>
<Text>skip this step</Text>
</View>
</TouchableHighlight>
</View>
</View>
);
}
};
var styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
alignItems: 'center',
backgroundColor: 'transparent'
},
bgImage: {
flex: 1,
width: window.width,
resizeMode: 'cover',
},
icontext: {
color: '#5d5d5d',
fontWeight: '400',
fontSize: 20,
backgroundColor: 'transparent',
paddingLeft: 10,
alignItems: 'center',
marginTop: window.height/2.2,
textAlign: 'center',
margin: 10,
},
bubblechoice_click: {
height: window.height/8.335,
borderRadius: (window.height/8.3350)/2,
marginRight: 2,
width: window.height/8.335,
},
bubblechoice: {
height: window.height/8.335,
borderRadius: (window.height/8.3350)/2,
marginRight: 2,
width: window.height/8.335,
},
row: {
flex: 1,
alignItems: 'center',
flexDirection: 'row',
justifyContent: 'center',
marginTop: -30,
},
choicetext: {
alignItems: 'center',
alignSelf: 'center',
color: 'white',
marginTop: 35,
fontWeight: '600',
marginLeft: -18,
fontSize: 14,
flex: 1,
textAlign: 'center'
},
overlay: {
backgroundColor:'rgba(80,94,104,0.7)',
height: 100,
width: 100,
alignItems:'center'
},
});
module.exports = LS1;
AppRegistry.registerComponent('main', () => LS1);
You can try it out by downloading Exponent to your phone from http://exponentjs.com/ (app store or beta, whichever you prefer) then loading up exp://exp.host/#brentvatne/button-color-exp

Simplest way with TouchableOpacity and active styles:
<TouchableOpacity
style={ this.state.active? styles.btnActive : styles.btn}
onPress={() => this.setState({active: !this.state.active})}>
</TouchableOpacity>