How to pass up nested state and avoid useCallback in react native - javascript

I have a parent and nest child component hierarchy of QuestionsAndAnswersScreen -> QuestionInput -> QuestionSelector -> AnswerSelector. I need to pass the question and answer object back up to the QuestionAndAnswerScreen in order to show it on the view. However I cannot find a way without going into deep nested callbacks.
Here is my code for the QuestionAnswerScreen and AnswerSelector:
function QuestionsAndAnswers() {
const {shell, body} = styles;
return (
<View style={shell}>
<SignUpHeader title="Add your answers" page={5}/>
<View style={body}>
{qAndA[1] ? <Answer question={qAndA[1].question} answer={qAndA[1].answer}/> : <QuestionInput />}
{qAndA[2] ? <Answer question={qAndA[2].question} answer={qAndA[2].answer}/> : <QuestionInput />}
{qAndA[3] ? <Answer question={qAndA[3].question} answer={qAndA[3].answer}/> : <QuestionInput />}
</View>
<SignUpFooter
title={`Questions\n& Answers`}
buttonTitle={"Done"}
disabled={false}
route="QuestionsAndAnswers"
/>
</View>
);
}
function AnswerInput(props: AnswerInputProps) {
const {question, visible, answerModalVisible} = props;
const {pickAnAnswer, doneButton, answerTextInput, questionStyle, shell, buttonText} = styles;
const [modalVisible, setModalVisible] = useState(visible)
const [answer, setAnswer] = useState('');
const navigation = useNavigation();
useEffect(() => {
setModalVisible(visible)
}, [visible])
function answerQuestion() {
setModalVisible(false);
navigation.navigate('QuestionsAndAnswers');
}
return (
<View>
<Modal style={shell}
isVisible={modalVisible}
onBackdropPress={() => {
setModalVisible(false);
answerModalVisible(false);
}}
>
<View>
<Text style={pickAnAnswer}>Add answer</Text>
</View>
<View>
<Text style={questionStyle}>{question}</Text>
</View>
<View>
<TextInput
style={answerTextInput}
placeholder="Add your answer here..."
placeholderTextColor="#878787"
onChangeText={(text: string) => setAnswer(text)}
/>
<View style={{alignItems: 'flex-end', marginTop: 44}}>
<TouchableOpacity style={doneButton} onPress={() => answerQuestion()}>
<Text style={buttonText}>
Done
</Text>
</TouchableOpacity>
</View>
</View>
</Modal>
</View>
);
}
As you can see I get my Question and Answer in the AnswerInput but then need to navigate back to the main screen in order to display them. Any help would be great thanks :)

Related

undefined is not a function(near '...datas.map....')

This is my data
[{"size":"Small","price":"90"},{"size":"Large","price":"180"},{"size":"Extra Large","price":"200"}]
and this is my code
const route = useRoute();
const [datas, setDatas] = useState([]);
useEffect(() => {
setDatas(route.params.item_sizes);
},[])
const ItemSizes = () => {
if(datas.length > 0)
{
console.log("Item size data: ", datas); //for debugging purposes
return(
<View>
{datas.map((data,key) => (
<View key={key}>
<View style={{flex:0.2}}>
<MaterialCommunityIcons name={"radiobox-blank"} size={20} color={'gray'}/>
{/* <Text style={{fontSize:16, fontWeight:'bold'}}>Icon</Text> */}
</View>
<View style={{flex:1}}>
<Text style={{fontSize:16, fontWeight:'bold'}}>{data.size}</Text>
</View>
<View style={{flex:1, flexDirection:'row-reverse'}}>
<Text style={{fontSize:16, fontWeight:'bold'}}>{data.price}</Text>
</View>
</View>
))}
</View>
)
}
}
I call it from my view like this
return (
<View>
{ItemSizes()}
</View>
)
So after I checked there's a data on datas so why it is undefined? Please do explain why it is returning me undefined even though there's a data?? Thank you
Check if the data you are setting is an array or string. If it's string set it like below by parsing
setData(JSON.parse(route.params.item_sizes));

const [item1, item2] inside class component (react-native)?

I've been working on a React-Native project.
For export default function App() INSERT 1 to 3 (on code) works.
For export default class App extends Component none of the INSERT's works.
I have to combine them since the modal gives the user the ability to insert text inside the modal and then process the data to console.log and from there use the data.
export default class App extends Component {
{/* INSERT 1 before render also gives error */}
render () {
{/* INSERT 1 */}
const [list, setList] = useState();
const HandleAddList = () => {
console.log(list);
{/* INSERT 1 END */}
return (
<View>
<Modal
animationType = {"slide"}
transparent={false}
visible={this.state.isVisible}>
<View style={styles.ModalContext}>
<View style={styles.ModalNavigation}>
<Text style={[styles.closeText, styles.navText]}
onPress={() => {
this.displayModal(!this.state.isVisible);
}
}> Cancel </Text>
<Text style = {[styles.navHeader, styles.navText] }>
New</Text>
<Text style={[styles.doneText, styles.navText]}
onPress={() => {
this.displayModal(!this.state.isVisible);
{/* INSERT 2 */}
HandleAddList();
{/* INSERT 2 */}
}
}> Done </Text>
</View>
<TextInput
style={styles.inputText}
placeholder='Enter Something...'
{/* INSERT 3 */}
value = {list}
onChangeText={text => setList(text)}
{/* INSERT 3 */}
autoFocus
/>
</View>
</Modal>
{/* Rest of the code */}
</View>
{/* const stylesheets etc. */}
React-native's documentation told me that I can't use const inside a class component. (https://reactjs.org/warnings/invalid-hook-call-warning.html).
INSERT-comments were only for the purpose of the question and testing was done without it...
All the needed modules was imported from 'react-native'
Any solutions? Would be grateful if someone can help...
You can't use Hooks on Class Components, it's only a Functional Components' feature. Instead of that you could use this,I'm not pretty sure about some things but you can fix the errors:
import styles from './styles.css'
export default function App() {
const [list, setList] = useState();
const [isVisible, setIsVisible] = useState(true);
const HandleAddList = () => {
console.log(list);
}
return (
<View>
<Modal
animationType={"slide"}
transparent={false}
visible={isVisible}>
<View style={styles.ModalContext}>
<View style={styles.ModalNavigation}>
<Text style={[styles.closeText, styles.navText]}
onPress={() => {
setIsVisible(!isVisible);
}
}> Cancel </Text>
<Text style={[styles.navHeader, styles.navText]}>
New</Text>
<Text style={[styles.doneText, styles.navText]}
onPress={() => {
setIsVisible(!isVisible);
HandleAddList();
}
}> Done </Text>
</View>
<TextInput
style={styles.inputText}
placeholder='Enter Something...'
value={list}
onChangeText={text => setList(text)}
autoFocus
/>
</View>
</Modal>
</View>
)
}
I'm not used to Class Components, but I think this can guide you:
export default class App extends Component {
constructor() {
super()
this.state = {
isVisible: true,
list: ""
}
}
HandleAddList () {
console.log(this.state.list);
}
render () {
return (
<View>
<Modal
animationType={"slide"}
transparent={false}
visible={this.state.isVisible}>
<View style={styles.ModalContext}>
<View style={styles.ModalNavigation}>
<Text style={[styles.closeText, styles.navText]}
onPress={() => {
this.setState({...this.state, isVisible: !this.state.isVisible});
}
}> Cancel </Text>
<Text style={[styles.navHeader, styles.navText]}>
New</Text>
<Text style={[styles.doneText, styles.navText]}
onPress={() => {
this.setState({...this.state, isVisible: !this.state.isVisible});
this.HandleAddList();
}
}> Done </Text>
</View>
<TextInput
style={styles.inputText}
placeholder='Enter Something...'
value={this.state.list}
onChangeText={text => this.setState({ ...this.state, list: text})}
autoFocus
/>
</View>
</Modal>
</View>
)
}
}
It's so important you read the documentation (https://es.reactjs.org/docs/state-and-lifecycle.html) by yourself, there's a pair of things here you could fix reading it. It's a pleasure to help anyway, hope this works for you.

How can i set focus to only one TextInput in list item after TouchableOpacity pressed in this item?

I have a list of many items where each item has TextInput and TouchableOpacity wrapped by View.
I've trying to set focus on TextInput in the list item in which TouchableOpacity has been pressed. It's needed for editing each item's name.
Below is the code of how I tried to do this. The problem of this code is that after pressing on any of the TouchableOpacity the last TextInput will always be focused due to the fact that the last iteration overwrites textInputRef.
Is there a way to make textInputRef contain a reference to the TextInput which TouchableOpacity will press?
const ListComponent = ({list}) => {
const textInputValue = useRef('');
const textInputRef = useRef(null);
changeItemName = (text) => {
textInputValue.current = text;
};
return (
<ScrollView>
{list.length > 0 &&
list.map((item) => (
<View key={item._id}>
<TouchableOpacity>
<View
<Text>{`Item: `}</Text>
<TextInput ref={textInputRef} onChangeText={changeItemName}>
{item.name}
</TextInput>
</View>
</TouchableOpacity>
<TouchableOpacity
onPress={() => {
textInputValue.current = '';
}}>
<Icon name={'check'} size={25} color="#000" />
</TouchableOpacity>
<View>
<TouchableOpacity
onPress={() => {
textInputValue.current = item.name;
textInputRef.current.focus();
}}>
<Icon name={'edit'} size={25} color="#000" />
</TouchableOpacity>
</View>
</View>
))}
</ScrollView>
);
};
I think creating an array of ref will help you to resolve.
Try this way
const ListComponent = ({list}) => {
const textInputValue = useRef('');
const textInputRef = useRef(null);
changeItemName = (text) => {
textInputValue.current = text;
};
const collectionRef = useRef(list.map(() => createRef()));
return (
<ScrollView>
{list.length > 0 &&
list.map((item, index) => (
<View key={item._id}>
<TouchableOpacity>
<View
<Text>{`Item: `}</Text>
<TextInput ref={collectionRef.current[index]} onChangeText={changeItemName}>
{item.name}
</TextInput>
</View>
</TouchableOpacity>
<TouchableOpacity
onPress={() => {
textInputValue.current = '';
}}>
<Icon name={'check'} size={25} color="#000" />
</TouchableOpacity>
<View>
<TouchableOpacity
onPress={() => {
textInputValue.current = item.name;
collectionRef[index].current.focus();
}}>
<Icon name={'edit'} size={25} color="#000" />
</TouchableOpacity>
</View>
</View>
))}
</ScrollView>
);
};

pass data between screens with getParamas

I'm rendering a few items in my map in ContactListand upon clicking on the thumbnail, I want to navigate to a new screen UserDetailsScreen such that the data about the clicked item is also passed along.
Previously I was using modals, but now I trying to switch to react-navigation.
ContactList.tsx:
export const ContactList: React.FunctionComponent<UserProps> = ({
data,
onDeleteContact,
}) => {
const [isUserVisible, setIsUserVisible] = useState(false);
//const [visibleUser, setVisibleUser] = useState<any>();
const navigation = useNavigation();
return (
<View style={styles.users}>
{data.users.nodes[0].userRelations.map(
(item: { relatedUser: RelatedUser; id: number }) => {
const numberOfFriends = item.relatedUser.userRelations.length;
const numberPlate = 'WHV AB 123';
return (
<View style={styles.item} key={item.id}>
{/* <TouchableOpacity onPress={() => setIsUserVisible(true)}> */}
<TouchableOpacity
onPress={() =>
navigation.navigate('UserDetailsScreen', {
firstName: item.relatedUser.firstName,
rating: item.relatedUser.rating,
numberOfFriends: numberOfFriends,
onDeleteContact: onDeleteContact,
isUserVisible: isUserVisible,
setIsUserVisible: setIsUserVisible,
numberPlate: numberPlate,
navigation: navigation,
})
}>
<Thumbnail
}}></Thumbnail>
</TouchableOpacity>
<View style={styles.nameNumber}>
<Text style={styles.userName}>{userName}</Text>
</View>
{/* <UserDetails
firstName={item.relatedUser.firstName}
rating={item.relatedUser.rating}
numberOfFriends={numberOfFriends}
onDeleteContact={onDeleteContact}
isUserVisible={isUserVisible}
setIsUserVisible={setIsUserVisible}
numberPlate={numberPlate}>
</UserDetails> */}
</View>
);
},
)}
</View>
);
};
UserDetailsScreen:
export const UserDetailsScreen: React.FunctionComponent<UserProps> = ({
firstName,
rating,
numberOfFriends,
numberPlate,
onDeleteContact,
navigation,
// isUserVisible,
// setIsUserVisible,
}) => {
//const navigation = useNavigation();
const fName = navigation.getParam('firstName')
return (
// <Modal visible={isUserVisible}>
<View style={styles.container}>
<View>
<TouchableOpacity
style={styles.cross}
//onPress={() => setIsUserVisible(false)}>
onPress={() => navigation.navigate('Whitelist')}>
<Thumbnail></Thumbnail>
</TouchableOpacity>
</View>
<View style={styles.searchLocationContainer}>
<UserInfoContainer
firstName={firstName}
rating={rating}
numberPlate={numberPlate}
numberOfFriends={numberOfFriends}></UserInfoContainer>
</View>
</View>
// </Modal>
);
};
Similarly, when I click on the thumbnail on this screen, I want to go back to my previous page where I can click on another object.
However, I keep getting an error that navigation.getParam is undefined. How can I fix this?
Hi you will get the data sent in the navigation params in
props.route.params

React Native : How to call child refs from the parent's event funtion?

Have parent tag as <TouchableWithoutFeedback> and child as <Image>, trying to change the image source from the parent onPress function, but getting error. how can I archive this using refs? or any other way to resolve it?
React-native version : 0.56
Error :
Cannot read property 'favIcon' of undefined
Sample Code :
const fav = require('../../images/favorite.png');
const nonfav = require('../../images/not_favorite.png');
updateFavorite = (id) => {
this.props.refs.favIcon.source(fav);
}
render(){
return (
<View style={styles.container}>
<TouchableWithoutFeedback onPress={ this.updateFavorite.bind(this, 1) }>
<View style={ styles.imageView }>
<Image refs="favIcon" source={ nonfav } />
</View>
</TouchableWithoutFeedback>
<TouchableWithoutFeedback onPress={ this.updateFavorite.bind(this, 2) }>
<View style={ styles.imageView }>
<Image refs="favIcon" source={ nonfav } />
</View>
</TouchableWithoutFeedback>
</View>
)
}
Note : change only the child image of onPressed, not all images.
try it using nativeProps, like
import resolveAssetSource from 'resolveAssetSource';
this.refs['favIcon'].setNativeProps({
src: [resolveAssetSource(fav)]
});
refer this for more.
It might not work with react-native 0.50+ versions but according to this comment it should work with 0.57.1
Updating properties of elements in React is best done by calling setState method. Try the following
updateFavorite = (event) => {
event.target.setAttribute('src', fav)
}
render(){
return (
<View style={styles.container}>
<TouchableWithoutFeedback>
<View style={ styles.imageView }>
<img ref={ref => this.favIcon = ref} src={nonFav} onPress={ this.updateFavorite }/>
</View>
</TouchableWithoutFeedback>
<TouchableWithoutFeedback>
<View style={ styles.imageView }>
<img ref={ref => this.favIcon = ref} src={nonFav} onPress={ this.updateFavorite } />
</View>
</TouchableWithoutFeedback>
</View>
)
}

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