I made a button component which I render in my Parent component. Been stuck for a while now on trying to fire a function on the onPress event of this child component that is used in my Parent.
I've been looking through some of the recommended questions and answers but I need some specific advice.
I simplified my code as much as possible, please have a quick look.
Thanks in advance!
// PARENT COMPONENT
export class Home extends Component {
constructor(props) {
super(props);
this.onPress = this.onPress.bind(this);
}
onPress = () => {
console.log("Hey");
};
render() {
return (
<View style={styles.container}>
<PrimaryButton text={"Sign up"} onPress={this.onPress} />
</View>
);
}
}
// CHILD COMPONENT
const PrimaryButton = ({ text }) => {
return (
<TouchableOpacity style={style.container} >
<Text style={style.text}>{text}</Text>
</TouchableOpacity>
);
};
export default PrimaryButton;
You need to pass onPress to TouchableOpacity as a prop. I don't know the props for TouchableOpacity but should be bound as either onPress or onClick. Event handlers always need to be passed to the root component (or as close to it as you can get, ie TouchableOpacity is from a 3rd party). Most, if not all, 3rd party components will have props for the proper events.
// CHILD COMPONENT
const PrimaryButton = ({ text, onPress }) => {
return (
<TouchableOpacity style={style.container} onClick={onPress} >
<Text style={style.text}>{text}</Text>
</TouchableOpacity>
);
};
Related
I've tried a few methods to get setState() to update the value of state. Currently the text in the <TextInput> changes, but the value in this.state doesn't change.
I have the console.log in the right place, I've tried writing external functions, I've messed around with the variable's names but nothing seems to work.
import * as React from 'react';
import { View, Text, TextInput, TouchableHighlight, Dimensions, StyleSheet } from "react-native";
import PropTypes from "prop-types";
class EditNote extends React.Component{
constructor(props){
super(props)
this.state = {
title: '',
text: '',
id: ''
}
}
// TODO: Change textboxes to match the props from the NoteList
static getDerivedStateFromProps(props){
return(
{...props.route.params}
)
}
render(){
return(
<View style={s.container}>
<View style={s.titleContainer}>
<Text style={s.titleText}>Edit Note</Text>
<View style={{flex: 1}}/>
</View>
<View style={s.inputContainer}>
<TextInput
style={{...s.input, ...s.titleInput}}
autoCapitalize='words'
keyboardAppearance='dark'
placeholderTextColor='#DDD'
onChangeText={(title) => { this.setState({title: title}, () => console.log(this.state)) }}
defaultValue={this.state.title}
/>
<TextInput
style={{...s.input, ...s.textInput}}
autoCapitalize='sentences'
keyboardAppearance='dark'
placeholderTextColor='#DDD'
multiline
onChangeText={(text) => { this.setState({text: text}, () => console.log(this.state)) }}
defaultValue={this.state.text}
/>
</View>
<View style={s.buttonContainer}>
<TouchableHighlight
style={s.backButton}
onPress={() => this.props.nav.navigate('NoteListView')}
underlayColor='#300030'
>
<Text style={s.buttonText}>Cancel</Text>
</TouchableHighlight>
<TouchableHighlight
style={s.addButton}
onPress={() => {
console.log(this.state.note)
this.props.nav.navigate('NoteListView', {note: this.state, mode: 'edit'})
}}
underlayColor='#300030'
>
<Text style={s.buttonText}>Edit</Text>
</TouchableHighlight>
</View>
</View>
)
}
}
export default EditNote
I just realized that this is a problem with two parts.
The first problem is that props.route.params is unaffected by subsequent render() calls. This means that even if you re-render the component, the same initial properties are used.
The second is getDerivedStateFromProps(). Every time the render function is called it calls getDerivedStateFromProps() right before it which sets the state to the initial route parameters.
This problem can be fixed by:
Clearing the initial route parameters in the render function after their initial use. Something a little like this at the beginning of the render()function will work. this.props.route.params = undefined
Using an if statement and a variable in state to regulate when the props should update the state.
Refactor the code to make use of the props
Option 3 is how things should be correctly done but the best solution depends on how your code works.
i had this issue where i'm trying to make sure the parent's onPress is triggered, but it wont
im trying to create a custom touchableOpacity component that able can be reusable, that wrap other Component so it can decide if the children can be shown or not and decide/alter what happen when the children component is pressed.
const CustomTouchable = (children, onPress) => {
function handleOnPress = () => {
if(validation){
onPress();
}
}
return <TouchableOpacity onPress={handleOnPress}>{children}</TouchableOpacity>
}
const MainComponent = () => {
function onPress = () => {console.log('test')}
<CustomTouchable onPress={onPress}>
<TouchableOpacity style={styles.button}>
<Text>Press Here</Text>
</TouchableOpacity>
</CustomTouchable>
}
but the parent onPress is not triggered, how can i trigger it?
This is because the touch event is received by the children and not the parent. Assign following prop to your Child Component
pointerEvents={"none"}
Make the second TouchableOpacity disabled like this
<TouchableOpacity onPress={onPress}>
<TouchableOpacity
disabled
style={styles.button}
>
<Text>Press Here</Text>
</TouchableOpacity>
</TouchableOpacity>
I have scroll view in my HomeScreen with my measures that is array of Measure component.
<ScrollView>{measures}</ScrollView>
My Measure component looks like this:
class Measure extends Component {
render() {
return (
<View key={this.props.keyval}>
<TouchableOpacity onPress={deleteItem(this.props.val.measure_id)}>
<Text style={styles.measure}>
ID: {this.props.val.measure_id}
</Text>
</TouchableOpacity>
</View>
);
}
deleteItem(id) {
// delete item
);
}
}
My question is, how to notify parent component HomeScreen that Measure was deleted to reload scroll view items? Or Maybe you have better idea how to:
display measures
delete one in onPress item
reload items in scroll view
Thans for any advices
In your case it should be something like this:
class HomeScreen extends Component {
state = {
measures: []
};
handleDelete = (id) => {
// item was deleted
}
render() {
const { measures } = this.state;
const measuresList = measures.map(measure => (
<Measure
key={measure.measure_id}
onDelete={this.handleDelete}
val={measure}
/>
));
return (
<ScrollView>{measuresList}</ScrollView>
);
}
}
class Measure extends Component {
render() {
return (
<View key={this.props.keyval}>
<TouchableOpacity onPress={deleteItem(this.props.val.measure_id)}>
<Text style={styles.measure}>
ID: {this.props.val.measure_id}
</Text>
</TouchableOpacity>
</View>
);
}
deleteItem(id) {
const { onDelete } = this.props;
// delete item
onDelete(id); //will call parent method.
}
}
I recommend using FlatList as it render only those items which are visible. Much better in terms of performance, especially in big lists taken from API.
Example:
<FlatList
data={measures}
keyExtractor={item => item.id}
renderItem={({ item }) => <Measure
id={item.id}
anyOtherNeededPropsKey={anyOtherNeededPropsValue}
/>}
/>
Pass an additional property onDelete to the Measure and call it in deleteItem method
I have a component and import it in specific screen, in this screen i have a button when clicks i open modal contain component it's a "recorder" so after i record voices i want to take this voice and save them into Parent screen as a state or something!
in the recorder component, I save voices data into state! but how can i pass it to other parent screens!?
so how can I handle it?
here is shots
Parent Screen "after click add voice I show the modal"
Parent Screen
Here's a modal contain a recorder component
Modal
CODE
Component
" I pass data to PassDataToModal state inside componentDidMount "
import React, {Component} from 'react';
import {Platform, StyleSheet, Text, TouchableOpacity, View} from 'react-native';
import {AudioRecorder, AudioUtils} from 'react-native-audio';
import Sound from 'react-native-sound';
import Icon from 'react-native-vector-icons/MaterialIcons';
class RecorderScreen extends Component {
state = {
PassDataToModal: null,
};
componentDidMount() {
AudioRecorder.requestAuthorization().then(isAuthorised => {
this.setState({hasPermission: isAuthorised});
AudioRecorder.onFinished = data => {
console.log('data', JSON.stringify(data));
this.setState({PassDataToModal: data});
};
});
}
render() {
return (
<View style={styles.container}>
<View style={styles.controls}>
{this._renderPlayButton(() => {
this._play();
})}
{this._renderRecordButton(this.state.recording)}
{this._renderStopButton('Stop', () => {
this._stop().then(() => this.setState({currentTime: 0}));
})}
</View>
<Text style={styles.progressText}>{this.state.currentTime}s</Text>
</View>
);
}
}
export default RecorderScreen;
Parent Screen
import Modal from 'react-native-modal';
import RecorderScreen from './Recorder';
class Order extends Component {
constructor(props) {
super(props);
this.state = {
isModalVisible: false,
};
}
toggleModal = () => {
this.setState({isModalVisible: !this.state.isModalVisible});
};
render() {
return (
<View style={styles.container}>
<TouchableOpacity
onPress={this.toggleModal}
>
<Icon name="mic" color="#333" size={20} />
<Text style={{paddingHorizontal: 5}}>Add Voice</Text>
</TouchableOpacity>
<Modal
style={{margin: 0}}
isVisible={this.state.isModalVisible}
>
<View>
<TouchableOpacity onPress={this.toggleModal}>
<Icon name="close" color="#000" size={25} />
</TouchableOpacity>
<RecorderScreen /> // Component
</View>
</View>
)
}
}
In your parent component pass a function to your RecorderScreen component that will send the necessary data up. Docs on lifting state up.
So in your parent you'd have something like:
setData = (data) => {
// Set this to whatever you need it to be named
this.setState({childData: data});
}
Then pass the function as a prop:
<RecorderScreen setData={this.setData} />
And finally, call it in the child however needed (If I'm following the code something like this):
componentDidMount() {
AudioRecorder.requestAuthorization().then(isAuthorised => {
this.setState({hasPermission: isAuthorised});
AudioRecorder.onFinished = data => {
this.props.setData(data);
};
});
}
Then your parent component will have access to the child's data that you have lifted up.
I have created modal in react native. I have added filter option icon in top right corner now when the user clicks on it should open the modal. How can I do that ? I have added Options icon in navigation.js but now how to connect it with modal component ?
In code below setModalVisible is available in filteroptions.js and not in navigation.js
Code:
navigation.js:
Updates: {
screen: UpdatesScreen,
navigationOptions: ({ navigation }) => ({
headerTitle: 'Myapp',
headerRight:<TouchableOpacity onPress={() => {this.setModalVisible(true);}}>
<MenuIcon style={{paddingLeft: 10, paddingRight: 15}} name="md-options" size={25} color="white"/>
</TouchableOpacity>,
})
},
filteroptions.js:
import React, {Component} from 'react';
import {Modal, Text, TouchableHighlight, View, Alert} from 'react-native';
export default class FilteroptionsModel extends Component {
state = {
modalVisible: false,
};
setModalVisible(visible) {
this.setState({modalVisible: visible});
}
render() {
return (
<View style={{marginTop: 22}}>
<Modal
animationType="slide"
transparent={false}
visible={this.state.modalVisible}
onRequestClose={() => {
Alert.alert('Modal has been closed.');
}}>
<View style={{marginTop: 22}}>
<View>
<TouchableHighlight
onPress={() => {
this.setModalVisible(!this.state.modalVisible);
}}>
<Text>Hide Modal</Text>
</TouchableHighlight>
</View>
</View>
</Modal>
</View>
);
}
}
When user clicks on filter button in top right corner (see screenshot) he should be able to see the box modal on screen:
Since it is a modal you don't necessarily need to add it to the navigation. You can just include it in your page and initially have it be invisible, then when the user clicks your button you can make the modal visible. But if you want to add it to the navigation why not just add like any other component. However, adding it to the navigation will take you to another page when you navigate to the component. Of course you can add a nested navigator to work around that, but I think it adds unnecessary complexity.
Update
You will first declare a Header component.
export default class MyHeader extends React.PureComponent {
render() {
<View>
<View>...Your left Icon here</View>
<View>...Your Title here</View>
<View>...Your right Icon Here</View>
</View>
}
}
Then in your page you will render this component first, pass as props your handlers and then render the rest of the page.
export default class MyPage extends React.PureComponent {
yourRigthHandler = () => {
this.setState({modaVisible: true});
}
yourLeftHandler = () => {....}
render() {
<View>
<MyHeader
LeftHandler={yourLeftHandler}
LeftHandler={yourRigthHandler}>
....
</MyHeader>
</View>
}
}
inside the handlers you can call the navigation functions to navigate to another page or change the components state to make the moda visible.The handlers will be passed as props to your header and you will add them as onPress handlers to your buttons.