I have a Main class which I show an array to user, then in detail page user can edit each element which I'm passing using react navigation parameter. I want to edit my array in the detail class and save it using async storage.
//Main.jsimport React from 'react';
import {
StyleSheet ,
Text,
View,
TextInput,
ScrollView,
TouchableOpacity,
KeyboardAvoidingView,
AsyncStorage
} from 'react-native'
import Note from './Note'
import detail from './Details'
import { createStackNavigator, createAppContainer } from "react-navigation";
export default class Main extends React.Component {
static navigationOptions = {
title: 'To do list',
headerStyle: {
backgroundColor: '#f4511e',
},
};
constructor(props){
super(props);
this.state = {
noteArray: [],
noteText: '',
dueDate: ''
};
}
async saveUserTasks(value) {
try {
await AsyncStorage.setItem('#MySuperStore:userTask',JSON.stringify(value));
} catch (error) {
console.log("Error saving data" + error);
}
}
getUserTasks = async() =>{
try {
const value = await AsyncStorage.getItem('#MySuperStore:userTask');
if (value !== null){
this.setState({ noteArray: JSON.parse(value)});
}
} catch (error) {
console.log("Error retrieving data" + error);
}
}
render() {
this.getUserTasks()
let notes = this.state.noteArray.map((val,key) => {
return <Note key={key} keyval={key} val={val}
deleteMethod={ () => this.deleteNote(key)}
goToDetailPage= {() => this.goToNoteDetail(key)}
/>
});
const { navigation } = this.props;
return(
<KeyboardAvoidingView behavior='padding' style={styles.keyboard}>
<View style={styles.container}>
<ScrollView style={styles.scrollContainer}>
{notes}
</ScrollView>
<View style={styles.footer}>
<TextInput
onChangeText={(noteText) => this.setState({noteText})}
style={styles.textInput}
placeholder='What is your next Task?'
placeholderTextColor='white'
underlineColorAndroid = 'transparent'
>
</TextInput>
</View>
<TouchableOpacity onPress={this.addNote.bind(this)} style={styles.addButton}>
<Text style={styles.addButtonText}> + </Text>
</TouchableOpacity>
</View>
</KeyboardAvoidingView>
);
}
addNote(){
if (this.state.noteText){
var d = new Date();
this.state.noteArray.push({
'creationDate': d.getFullYear() + "/" + (d.getMonth()+1) + "/" + d.getDay(), 'taskName': this.state.noteText,'dueDate':'YYYY/MM/DD'
});
this.setState({noteArray:this.state.noteArray})
this.setState({noteText: ''});
this.saveUserTasks(this.state.noteArray)
}
}
deleteNote(key){
this.state.noteArray.splice(key,1);
this.setState({noteArray: this.state.noteArray})
this.saveUserTasks(this.state.noteArray)
}
goToNoteDetail=(key)=>{
this.props.navigation.navigate('DetailsScreen', {
selectedTask: this.state.noteArray[key],
});
}
}
in detail view I have this method which is similar to add note in main class:
export default class Details extends React.Component {
render() {
const { navigation } = this.props;
const selectedTask = navigation.getParam('selectedTask', 'task');
return(
<View key={this.props.keyval} style={styles.container}>
<TouchableOpacity onPress={this.saveEdit.bind(this)} style={styles.saveButton}>
<Text style={styles.saveButtonText}> save </Text>
</TouchableOpacity>
</View>
);
}
saveEdit(){
let selectedItem = { 'creationDate': selectedTask['creationDate'],
'taskName': selectedTask['taskName'],
'dueDate': this.state.dueData}
this.props.navigation.state.params.saveEdit(selectedItem)
}
}
How can I change my props in any component?
First of all you shouldn't call this.getUserTasks() in the render method because the function has this.setState which is bad and could end in a endless loop I guess or at least effect in worse performance. You could instead call it in componentDidMount:
componentDidMount = () => {
this.getUserTasks();
}
Or alternatively call already in constructor but I prefer the first option:
constructor(props){
super(props);
this.state = {
noteArray: [],
noteText: '',
dueDate: ''
};
this.getUserTasks()
}
this.props.noteArray.push({.. is probably undefined because you aren't passing it down any where. (Didn't see any reference in your snippet). I guess I would implement the saveEdit function in the Main.js component and simply pass it down to the navigation route and call the function in Details component by accessing the navigation state props:
Update
goToNoteDetail=(key)=>{
this.props.navigation.navigate('DetailsScreen', {
// selectedTask: this.state.noteArray[key],
selectedItem: key,
saveEdit: this.saveEdit
});
}
saveEdit(selectedItem){
const selectedTask = this.state.noteArray[selectedItem]
this.state.noteArray.push({
'creationDate': selectedTask['creationDate'],
'taskName': selectedTask['taskName'],
'dueDate': this.state.dueData
});
this.setState({noteArray:this.state.noteArray})
this.setState({dueData: 'YYYY/MM/DD'});
this.saveUserTasks(this.state.noteArray)
}
And then call saveEdit in Details Component:
saveSelectedItem = () => {
const { navigation } = this.props.navigation;
const {selectedItem, saveEdit} = navigation.state && navigation.state.params;
saveEdit(selectedItem)
}
Related
NetInfo is used to check the connection & theres a checkNetwork function called in onPress of TouchableOpacity. When the button is clicked once, the checkNetwork
function is called automatically multiple times without tapping the button when the network connection is lost and vice versa.
Please have a look at the code here:
Please have a look at the video
export default class App extends React.Component {
checkNetwork = () => {
NetInfo.addEventListener((state) => {
if (state.isConnected) {
alert('isConnected');
} else {
alert('not connected');
}
});
};
render() {
return (
<View style={styles.container}>
<TouchableOpacity
activeOpacity={0.8}
onPress={()=> this.checkNetwork()}>
<Text>Check here</Text>
</TouchableOpacity>
</View>
);
}
}
You should not declare event listener inside of the click itself,
export default class App extends React.Component {
constructor(props) {
super(props);
this.state = {alert: ''};
}
componentDidMount() {
NetInfo.addEventListener((state) => this.setState({ alert: state.isConnected ? 'isConnected' : 'not connected'})
}
checkNetwork = () => alert(this.state.alert)
render() {
return (
<View style={styles.container}>
<TouchableOpacity
activeOpacity={0.8}
onPress={()=> this.checkNetwork()}>
<Text>Check here</Text>
</TouchableOpacity>
</View>
);
}
}
though in your case event listener isn't exactly the fit logic for UI behavior of pressing button, so I think you might wanna use useNetInfo
import {useNetInfo} from "#react-native-community/netinfo";
class App extends React.Component {
checkNetwork = () => {
if (this.props.netInfo.isConnected) {
alert('isConnected');
} else {
alert('not connected');
}
});
};
...rest render...
}
export default () => <App netInfo={useNetInfo()} />
I am new to react native. I have following component in my project for now I have written for fetching API in same component but want to separate it out. I am getting difficulty for how can i access variable which I am using in "getAlbum" method from outside of component.
Is there standard way to separate API call from component?
import React, { Component } from 'react';
import {
FlatList, Text, View, Image, TouchableOpacity,
} from 'react-native';
import { ActivityIndicator, Provider } from 'react-native-paper';
import axios from 'axios';
import styles from '../style/ThumbnailView.component.style';
import ErrorAlert from '../common/ErrorAlert';
import * as myConstant from '../common/Constants';
export default class HomeScreen extends Component {
// For to Navigation header
static navigationOptions = () => ({
headerTitle: 'Album Information',
});
constructor(props) {
super(props);
this.state = {
isLoading: true,
apiLoadingError: false,
};
}
getAlbums() {
const { navigation } = this.props;
const albumId = navigation.getParam('albumID', 'no data');
axios
.get(
myConstant.API + `photos?albumId=${albumId}`, {timeout: myConstant.TIMEOUT}
)
.then((response) => {
this.setState({
isLoading: false,
dataSource: response.data,
});
})
.catch(err => {
this.setState({isLoading: false, apiLoadingError: true})
});
}
componentDidMount() {
this.getAlbums();
}
render() {
if (this.state.isLoading) {
return (
<View style={{ flex: 1, paddingTop: 30 }}>
<ActivityIndicator animating={true} size='large' />
</View>
);
}
if (this.state.apiLoadingError) {
return (
<ErrorAlert />
);
}
return (
<React.Fragment>
<Provider>
<View style={styles.listContainer} >
<FlatList
testID='flatlist'
data={ this.state.dataSource } numColumns={3}
renderItem={({ item }) => <View style={styles.listRowContainer}>
<TouchableOpacity onPress={() => this.props.navigation.navigate('AlbumDetailsViewScreen', {
albumTitle: item.title, albumImg: item.url
})} style={styles.listRow}>
<View style={styles.listTextNavVIew}>
<Image source = {{ uri: item.thumbnailUrl }} style={styles.imageViewContainer} />
</View>
</TouchableOpacity>
</View>
}
keyExtractor = { (item, index) => index.toString() }
/>
</View>
</Provider>
</React.Fragment>
);
}
}
You can separate your axios call by making another class with function which will receive 'albumID' as an argument - then add it to your axios link. If you want to call this function from another class just make it static and use like in example below. Then you can map your fetchData to parse it into state. Hope it will help you.
export class Api {
static fetchData = (albumId: string) => {
//here your axios call which will return an array
}
}
export default class HomeScreen extends React.Component {
state = {
//.....
}
receivedData = Api.fetchData('albumID');
//you can map array here to get what you want.
}
I can navigate to a screen but params are undefined, state is just:
{
key: "id-1574950261181-7",
routeName: "Video Player"
}
Navigate from:
render() {
const {
id,
title,
description,
video,
preview,
push,
dispatch,
testLink,
navigate
} = this.props;
return (
<TouchableHighlight
style={styles.episode}
activeOpacity={1}
underlayColor="#808080"
onPress={() => {
navigate("VideoPlayer", { tester: id });
}}
>
<View style={styles.title}>
<Text style={styles.text}>{title}</Text>
</View>
</TouchableHighlight>
);
}
My VideoPlayerScreen (for brevity) gives me :
import React from "react";
import {
...
} from "react-native";
...
...
class VideoPlayerScreen extends React.Component {
constructor(props) {
super(props);
this.state = {};
this.onShare = this.onShare.bind(this);
this.navigateScreen = this.navigateScreen.bind(this);
this.bookmarkVideo = this.bookmarkVideo.bind(this);
this.loadRecapVideo = this.loadRecapVideo.bind(this);
}
....
render() {
const {
videos,
bookmarkVideo,
navigate,
state: {
params: { id }
}
} = this.props;
console.log(this.props.navigation.state.params);
let videoProps = videos.find(obj => obj.id == id);
return (<View />)
}
}
const mapDispatchToProps = dispatch => ({
bookmarkVideo: id => dispatch(bookmarkVideo(id))
});
const mapStateToProps = state => {
return {
videos: state.tcApp.videos
};
};
export default connect(
mapStateToProps,
mapDispatchToProps
)(VideoPlayerScreen);
In case you are using react-native-navigation 4x you should change the props variable
from:
const {
...
navigate,
} = this.props;
to:
const {
...
navigation,
} = this.props;
and call it like:
onPress={() => {
navigation.navigate("VideoPlayer", { tester: id });
}}
Official Doc: React Native Navigation Docs
Friendly.
I've made a full-screen TextInput and would like to have an action performed when the Post button in the NavigationBar is pressed. However, because I have to make the method that the Button is calling in the onPress prop a static method, I don't have access to the state.
Here is my current code, and the state comes up undefined in the console.log.
import React, { Component } from 'react';
import { Button, ScrollView, TextInput, View } from 'react-native';
import styles from './styles';
export default class AddComment extends Component {
static navigationOptions = ({ navigation }) => {
return {
title: 'Add Comment',
headerRight: (
<Button
title='Post'
onPress={() => AddComment.postComment() }
/>
),
};
};
constructor(props) {
super(props);
this.state = {
post: 'Default Text',
}
}
static postComment() {
console.log('Here is the state: ', this.state);
}
render() {
return (
<View onLayout={(ev) => {
var fullHeight = ev.nativeEvent.layout.height - 80;
this.setState({ height: fullHeight, fullHeight: fullHeight });
}}>
<ScrollView keyboardDismissMode='interactive'>
<TextInput
multiline={true}
style={styles.input}
onChangeText={(text) => {
this.state.post = text;
}}
defaultValue={this.state.post}
autoFocus={true}
/>
</ScrollView>
</View>
);
}
}
Any ideas how to accomplish what I'm looking for?
I see you've found the solution. For future readers:
Nonameolsson posted how to achieve this on Github:
In componentDidMount set the method as a param.
componentDidMount () {
this.props.navigation.setParams({ postComment: this.postComment })
}
And use it in your navigationOptions:
static navigationOptions = ({ navigation }) => {
const { params } = navigation.state
return {
title: 'Add Comment',
headerRight: (
<Button
title='Post'
onPress={() => params.postComment()}
/>
),
};
};
Kinda like a hack but i use the global variable method where we assign this to a variable call foo. Works for me.
let foo;
class App extends Component {
static navigationOptions = ({ navigation }) => {
return {
title: 'Add Comment',
headerRight: (
<Button
title='Post'
onPress={() => foo.postComment() } <- Use foo instead of this
/>
),
};
};
componentWillMount() {
foo = this;
}
render() {
return (<div>Don't be a foo</div>)
}
}
I am trying to update ListView.DataSource after fetching data from server but its not happening. I have two components, one is imported in other.
From base component I am trying to update ListView.DataSource in other component. Here is my code.
index.android.js
import React, { Component } from "react";
import { ListView, View, Button, AppRegistry } from "react-native";
import OtherComponent from "./Components/OtherComponent";
class MyApp extends Component {
constructor(props) {
super(props);
this.state = {
movies: [{ title: "ABCD" }, { title: "EFGH" }]
};
}
getTopics = () => {
fetch("https://facebook.github.io/react-native/movies.json")
.then(response => response.json())
.then(responseText => {
console.log(responseText.movies);
this.setState({
movies: responseText.movies
});
})
.catch(error => {
console.warn(error);
});
};
render() {
return (
<View>
<Button
onPress={this.getTopics}
title="Get Topics"
color="#841584"
accessibilityLabel="Learn more about this purple button"
/>
<OtherComponent movies={this.state.movies} />
</View>
);
}
}
AppRegistry.registerComponent("MyApp", () => MyApp);
OtheComponent.js
import React, { Component } from "react";
import { View, ListView, Text, StyleSheet, Button } from "react-native";
export default class FormativeRevisionList extends Component {
constructor(props) {
super(props);
const ds = new ListView.DataSource({
rowHasChanged: (r1, r2) => r1 !== r2
});
this.state = {
dataSource: ds.cloneWithRows(props.movies)
};
}
render() {
return (
<View>
<ListView
style={styles.listContainer}
dataSource={this.state.dataSource}
renderRow={rowData => (
<View>
<Text style={styles.listItem}>{rowData.title}</Text>
</View>
)}
/>
</View>
);
}
}
const styles = StyleSheet.create({
listContainer: {
paddingTop: 22
},
listItem: {
fontSize: 30,
fontWeight: "bold",
textAlign: "center"
}
});
In your code, you only set your dataSource in contructor of FormativeRevisionList, this mean FormativeRevisionList will only render the given movies when your first render it.
To render new list after you press Get Topics button , you need to set the dataSource again when it receive new props, this can be achieve by setting it in FormativeRevisionList componentWillReceiveProps
componentWillReceiveProps(nextProps) {
if (nextProps.movies !== this.props.movies) {
this.setState({
dataSource: this.state.dataSource.cloneWithRows(nextProps.movies)
})
}
}
You can read more about componentWillReceiveProps from here