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>
I have a screen where I input some values in the input field and get search results displayed accordingly (within the <View style={styles.dropdown}>). I want that the list should overlap my ActionButton. Just like it overlaps my other input field.
I have already added zIndex and it works for the second input field but not for the button.
return (
<SafeAreaView style={styles.safeAreaViewContainer}>
<View style={styles.container}>
<View style={styles.searchFieldContainer}>
<AddressSearchInput
addressType="favouritePoint"
iconName="search"
textChangeHandler={textChangeHandler}/>
</View>
<View style={styles.dropdown}>
<LocationsFound
addressesFound={locations.addressesFoundList}/>
</View>
<View style={styles.fieldDescription}>
<Text>Standortname:</Text>
</View>
<View style={styles.searchFieldContainer}>
<Item style={styles.searchField}>
<Input style={styles.searchText}/>
</Item>
</View>
<View style={styles.buttonContainer}>
<ActionButton buttonText="Platz Speichern"/>
</View>
</View>
</SafeAreaView>
);
};
export const styles = StyleSheet.create({
searchFieldContainer: {
alignItems: 'center',
height: moderateScale(120),
},
buttonContainer: {
flexDirection: 'row',
justifyContent: 'center',
zIndex: 1,
},
fieldDescription: {
alignItems: 'center',
},
dropdown: {
position: 'absolute',
top: moderateScale(215),
zIndex: moderateScale(10),
backgroundColor: '#fff',
},
container: {
height: '100%',
backgroundColor: 'white',
width: '100%',
flex:1,
},
});
You have to add styles to your <View style={styles.container}>. Like:
container: {
display:"flex",
flex-direction:"column",
//etc
}
Because now your Views are all separate from each other.
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,
}
})
Cannot figure out why I keep getting a ReferenceError cant find variable MarkAsRead for a mobile app I am building in react. Unless I am missing something the variable has been assigned below is the code for your reference. Hopefully, someone can help me get this bug resolved in a timely matter thanks in advance!
import React from 'react';
import { View,
Text,
StyleSheet,
SafeAreaView,
TouchableOpacity,
TextInput,
FlatList
} from 'react-native';
import BookCount from './components/BookCount';
import {Ionicons} from '#expo/vector-icons';
class App extends React.Component {
constructor() {
super()
this.state = {
totalCount: 0,
readingCount: 0,
readCount: 0,
isAddNewBookVisible:false,
textInputData: '',
books: [],
bookData: {
author: '',
publisher: ''
}
};
}
showAddNewBook = () => {
this.setState({isAddNewBookVisible:true});
};
hideAddNewBook = () => {
this.setState({isAddNewBookVisible:false})
};
addBook = book => {
this.setState(
(state, props) => ({
books: [...state.books, book],
totalCount: state.totalCount + 1,
readingCount:state.readingCount + 1,
isAddNewBookVisible: false
}),
() => {
console.log(this.state);
}
);
};
markAsRead = (selectedBook, index) => {
let newList = this.state.books.filter(book => book !==
selectedBook);
this.setState(prevState => ({
books: newList,
readingCount: prevState.readingCount - 1,
readCount: prevState.readCount + 1
}));
};
renderItem = (item, index) => (
<View style={{ height:50, flexDirection: 'row'}}>
<View style={{ flex:1, justifyContent: 'center', paddingLeft: 5
}}>
<Text>{item}</Text>
</View>
<TouchableOpacity onPress={() => markAsRead(item,index)} >
<View
style={{
width: 100,
height: 50,
alignItems: 'center',
justifyContent: 'center',
backgroundColor: '#160b1a'
}}
>
<Text style={{ fontWeight: 'bold', color: 'white'}}>Mark as Read</Text>
</View>
</TouchableOpacity>
</View>
);
render() {
return (
<View style={{flex: 1}}>
<SafeAreaView/>
<View style={{
height: 70,
borderBottomWidth: 0.5,
borderBottomColor: '#5e3c7d',
alignItems: 'center',
justifyContent: 'center'
}}
>
<Text style={{fontSize: 24}}>VekTorfy AI</Text>
</View>
<View style={{ flex: 1}}>
{this.state.isAddNewBookVisible &&
<View style={{height:50, flexDirection: 'row'}}>
<TextInput
onChangeText={(text)=>this.setState({textInputData:text})}
style={{ flex:1, backgroundColor: '#c6c0cb',
paddingLeft: 5}}
placeholder='Enter book name.'
placeholderTextColor='black'
/>
<TouchableOpacity
onPress={() => this.addBook(this.state.textInputData)} >
<View style={{
width: 50,
height: 50,
alignItems: 'center',
justifyContent: 'center',
backgroundColor: '#160b1a'}}>
<Ionicons name ='ios-checkmark' color='white' size={40}/>
</View>
</TouchableOpacity>
<TouchableOpacity onPress={this.hideAddNewBook}>
<View style={{
width: 50,
height: 50,
alignItems: 'center',
justifyContent: 'center',
backgroundColor: '#160b1a'}}>
<Ionicons name ='ios-close' color='red' size={40}/>
</View>
</TouchableOpacity>
</View>
}
<FlatList
data={this.state.books}
renderItem={({item}, index) => this.renderItem(item, index)}
keyExtractor={(item, index)=> index.toString()}
ListEmptyComponent={
<View style={{marginTop: 50, alignItems: 'center'}}>
<Text style={{fontWeight: 'bold'}}>Not Reading anything.</Text>
</View>
}
/>
<TouchableOpacity
onPress={this.showAddNewBook}
style={{position: 'absolute', bottom: 20, right: 20}}>
<View
style={{
width:50,
heght:50,
alignItems: 'center',
justifyContent: 'center',
borderRadius:25,
backgroundColor: '#2d2337'}}>
<Text style={{color: 'white', fontSize: 30}}>+</Text>
</View></TouchableOpacity>
</View>
<View
style={{
height: 70,
flexDirection: 'row',
borderTopWidth: 0.5,
borderTopColor: '#5e3c7d' }}>
<BookCount title='Total' count={this.state.totalCount}/>
<BookCount title='Reading' count={this.state.readingCount}/>
<BookCount title='Read' count={this.state.readCount}/>
</View>
<SafeAreaView/>
</View>
);
}
}
export default App;
const styles = StyleSheet.create({
container: {
flex: 1,
alignItems: 'center',
justifyContent: 'center'
}
});
You forgot to add the keyword this to your function call.
<TouchableOpacity onPress={() => this.markAsRead(item,index)}>
It looks like you have declared markAsRead as a method on your App class, so the correct way to refer to it is this.markAsRead()
<TouchableOpacity onPress={() => this.markAsRead(item, index)}>
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>