I created a simple app, that shows a few pictures with titles. It is something like a film gallery, where you can observe all enable films. But when I try to add ScrollView element it doesn't work when I try to scroll on my emulated Android device. How can I fix it? My code looks like this:
import React, { Component } from 'react'
import { View, ScrollView, StyleSheet } from 'react-native'
import { Header, ImageCard } from './src/components/uikit'
const url = 'https://s3.eu-central-1.wasabisys.com/ghashtag/RNForKids/00-Init/data.json'
export default class App extends Component {
constructor(props) {
super(props);
this.state = {
title: 'STAR GATE',
data: []
};
}
componentDidMount = async () => {
try {
const response = await fetch(url)
const data = await response.json()
this.setState({ data })
}
catch (e) {
console.log(e)
throw e
}
}
render() {
const { title, data } = this.state
const { container } = style
return (
<View>
<Header title={title} />
<ScrollView>
<View style={container}>
{
data.map(item => {
return <ImageCard data={item} key={item.id} />
})
}
</View>
</ScrollView>
</View>
)
}
}
const style = StyleSheet.create({
container: {
marginTop: 30,
flexDirection: 'row',
flexWrap: 'wrap',
flexShrink: 2,
justifyContent: 'space-around',
marginBottom: 150
}
})
I made it with a guide, so it should work. (Youtubes author hasn't this problem on his video).
The View inside ScrollView looks problematic. Try something like:
<ScrollView contentContainerStyle={container} >
{
data.map(item => {
return <ImageCard data={item} key={item.id} />
})
}
</ScrollView>
Related
Flatlist component as below
<FlatList
data={this.state.data}
keyExtractor={item => item.ID.toString()}
renderItem={this.renderItem}
onRefresh={this.onRefresh}
refreshing={this.state.refreshing}
ListFooterComponent={this.renderFooter}
/>
renderItem = ({ item }) => {
return (
<ListElement onPress={() => this.rowData(item)} item={item}/>
);
};
ListItem Component
import React from "react";
import { Image } from "react-native";
import { Left, Right, Body, Text, ListItem } from "native-base";
import { widthPercentageToDP as wp, heightPercentageToDP as hp } from "react-native-responsive-screen";
import Thumbnails from "../components/Thumbnails";
import styles from "../styles/HomeStyles";
import GlobalStyles from "../constants/GlobalStyles";
class ListElement extends React.Component {
componentDidMount(){
console.log(this.props.item.ID)
}
shouldComponentUpdate(){
return false;
}
render() {
return (
<ListItem onPress={this.props.onPress} thumbnail style={styles.listItem}>
<Left>
<Thumbnails imageURI={require("../../assets/images/female2.png")} />
</Left>
<Body style={{ borderBottomColor: "transparent", top: 2 }}>
<Text
style={{
fontFamily: GlobalStyles.primaryFont,
fontSize: hp("1.85%"),
}}
>
{this.props.item.FirstName} {this.props.item.LastName}
</Text>
<Text
note
style={{
fontFamily: GlobalStyles.primaryFont,
color: "#666666",
fontSize: hp("1.6%"),
}}
>
{this.props.item.Title}
</Text>
</Body>
<Right>
<Image
style={styles.rightArrow}
source={require("../../assets/images/arrowRight.png")}
/>
</Right>
</ListItem>
);
}
}
export default ListElement;
I tried to populate api data on the flatlist. Please refer my above code for implementation. Currently I am facing rerendering issues as mentioned below.
My listitem componentDidMount is invoking multiple times on scroll after even intial render of all listitems.
I have tried PureComponent and shouldComponentUpdate. Thanks in advance.
An Update
Please Find the entire code of Flatlist component
import React, { PureComponent } from "react";
import { View, FlatList } from "react-native";
import { ListItem } from "react-native-elements";
import FL from "../screens/FL";
import FL1 from "../screens/Fl1";
class FlatListDemo extends PureComponent {
constructor(props) {
super(props);
this.state = {
loading: false,
data: [],
error: null,
refreshing: false,
};
}
componentDidMount() {
this.makeRemoteRequest();
}
makeRemoteRequest = () => {
const url = `https://jsonplaceholder.typicode.com/posts`;
this.setState({ loading: true });
fetch(url)
.then((res) => res.json())
.then((res) => {
this.setState({
data: res,
error: res.error || null,
loading: false,
refreshing: false,
});
})
.catch((error) => {
this.setState({ error, loading: false });
});
};
renderItem = ({ item }) => {
return <ListElement onPress={() => this.rowData(item)} item={item} />;
};
render() {
if (this.state.loading === true) {
return <View></View>;
} else {
return (
<View>
<FlatList
data={this.state.data}
keyExtractor={(item) => item.ID.toString()}
renderItem={this.renderItem}
onRefresh={this.onRefresh}
refreshing={this.state.refreshing}
ListFooterComponent={this.renderFooter}
/>
</View>
);
}
}
}
export default FlatListDemo;
Try the following:
add to state a boolean value (you can name it "wasFetched").
Then change the componentDidMount like this:
componentDidMount() {
if(this.state.wasFetched === false) {
this.setState({ wasFetched: true }, () => this.makeRemoteRequest())
}
}
I want to know how can I use the "userPrincipalName" on other pages.
what do I need to do to make it work?
in my example, I try to use the "userPrincipalName" object on the MainScreenpage but I don't understand how to do it.
this my example of the Modal page which it has the object "userPrincipalName":
import React,
{ Component } from 'react';
import {
Text,
TouchableOpacity,
StyleSheet,
View,
} from 'react-native';
import Modal from 'react-native-modal';
import PlacesNavigator from '../navigation/PlacesNavigator';
import { LinearGradient } from 'expo-linear-gradient';
import { AzureInstance, AzureLoginView } from 'react-native-azure-ad-2';
const credentials = {
client_id: 'ea00ca9e-8c37-4520-8d80-2c2bb9239bf8',
scope: 'User.Read',
};
export default class Example extends Component {
constructor(props) {
super(props);
this.state = {
visibleModal: 3,
azureLoginObject: {},
loginSuccess: false
};
this.azureInstance = new AzureInstance(credentials);
this._onLoginSuccess = this._onLoginSuccess.bind(this);
}
_renderButton = () => (
<TouchableOpacity
onPress={() => this.setState({ visibleModal: false })}>
<LinearGradient
colors={['#4c669f', '#3b5998', '#192f6a']}
style={{
height: 80,
width: 180,
borderRadius: 10,
backgroundColor: "#2196F3",
justifyContent: 'center',
alignItems: 'center',
marginTop: 50,
}}>
<Text style={{ color: 'white', fontSize: 20, fontWeight: 'bold' }}>כניסה</Text>
</LinearGradient>
</TouchableOpacity>
);
_onLoginSuccess() {
this.azureInstance.getUserInfo().then(result => {
this.setState({
loginSuccess: true,
azureLoginObject: result,
});
console.log(result);
}).catch(err => {
console.log(err);
})
}
renderWelcomeMsg = (currentTime = new Date()) => {
const currentHour = currentTime.getHours()
const splitAfternoon = 12;
const splitEvening = 17;
if (currentHour >= splitAfternoon && currentHour <= splitEvening) {
return 'צהריים טובים,';
} else if (currentHour >= splitEvening) {
return 'ערב טוב,';
}
return 'בוקר טוב,';
}
render() {
if (!this.state.loginSuccess) {
return (
<AzureLoginView
azureInstance={this.azureInstance}
onSuccess={this._onLoginSuccess}
/>)
}
if (this.state.visibleModal === 3) {
const { givenName } = this.state.azureLoginObject;
const { userPrincipalName } = this.state.azureLoginObject;////THIS IS THE OBJECT I WANT
return (
<View style={styles.container}>
<Modal
isVisible={this.state.visibleModal === 3}
animationInTiming={1000}
animationOutTiming={1000}
backdropTransitionInTiming={4000}
backdropTransitionOutTiming={4000}
animationIn={'flipInY'}
>
<LinearGradient
colors={['#43D4FF', 'white']}
style={{ borderRadius: 10 }}>
<View style={styles.modalContent}>
<Text style={{
fontWeight: "bold",
fontSize: 35,
justifyContent: 'center',
alignItems: 'center',
}}>{this.renderWelcomeMsg()} {givenName}
</Text>
<View style={styles.buttonContainer}>
{this._renderButton()}
</View>
</View>
</LinearGradient>
</Modal>
</View>
);
}
return (
<PlacesNavigator />
);
}
}
And this is the MainScreen page that i want to use the object "userPrincipalName" in the Axios:
import React, { Component } from "react";
import {
View,
Text,
StyleSheet,
ActivityIndicator,
Platform,
FlatList,
TouchableOpacity,
TouchableHighlight,
WebView
} from "react-native";
import { HeaderButtons, Item } from "react-navigation-header-buttons";
import HeaderButton from "../components/HeaderButton";
import axios from "axios";
import moment from 'moment'
import storeService from '../components/storeService'
export default class MainScreen extends Component {
constructor(props) {
super(props);
this.state = {
data: [],
userPrincipalName: null
};
}
getData = () => {
this.setState({ isLoading: true, data: [] })
axios.get("https://harigotphat1.mekorot.co.il/ConfirmPackaotWS/OrderApprove/OrderApp_Get_Orders_To_Approve/" + userPrincipalName.split('#')[0])
.then(res => {
this.setState({
isLoading: false,
data: res.data
});
console.log(res.data);
});
}
componentDidMount() {
this.props.navigation.setParams({ getData: this.getData });
// now we load the data we stored in the async storage
storeService.loadKey('userPrincipalName').then((res) => {
console.log("THIS IS THE userPrincipalName", res) //res will contain the value given the key, store this value in your state and use it any where in the component
})
this.getData()
// this.postData()
}
renderItems = (item, index) => {
const { merhavid, yaamID, ezorID, shemEzor } = item;
return (
<TouchableHighlight style={{
backgroundColor: '#ffff78'
}}>
<TouchableOpacity
style={{
paddingVertical: 15,
paddingHorizontal: 10,
flexDirection: "row",
justifyContent: "space-between",
alignItems: "center",
borderWidth: 0.8,
borderColor: '#d5d7db',
backgroundColor: index % 2 == 0 ? '#d1f0da' : '#f2f5f3',
}}
onPress={() => this.props.navigation.navigate("Info")}>
<Text style={styles.name}>
{ezorID + "" + " |" + " " + merhavid + " " + yaamID + " " + shemEzor}
</Text>
</TouchableOpacity>
</TouchableHighlight>
);
}
render() {
if (this.state.isLoading) {
return (
<View style={{ flex: 0, paddingTop: 300 }}>
<Text style={{ alignSelf: "center", fontWeight: "bold", fontSize: 20 }}>טוען נתונים...</Text>
<ActivityIndicator size={'large'} color={'#08cbfc'} />
</View>
);
}
return (
<>
<View style={styles.container}>
<FlatList
data={this.state.data}
keyExtractor={(_, index) => String(index)}
renderItem={({ item, index }) => { return this.renderItems(item, index) }}
/>
</View>
<View style={styles.bottomMainContainer}>
<View style={styles.bottomView} >
<Text style={styles.bottomTextStyle}>סה"כ: {this.state.data.length} רשומות</Text>
</View>
</View>
</>
);
}
}
This is what React Context was designed for:
Context provides a way to pass data through the component tree without having to pass props down manually at every level.
This also applies to updating data from nested components e.g.
const UserContext = React.createContext({
user: null,
setUser: () => {}
});
function UserContextProvider {
const [user, setUser] = useState(null);
return (
<UserContext.Provider value={{ user, setUser }}>
{props.children}
</UserContext.Provider>
)
}
function App() {
return (
<UserContextProvider>
<MainScreen />
</UserContextProvider>
);
}
class MainScreen extends Component {
static contextType = UserContext;
getData() {
// We should see the user details
console.log(this.context.user);
}
render() {
return (
<div>
<Example />
</div>
)
}
}
class Example extends Component {
static contextType = UserContext
_onLoginSuccess() {
this.azureInstance.getUserInfo().then(result => {
this.setState(...);
// set user in UserContext
this.context.setUser(result);
});
}
}
The best way would be use redux store which helps you create immutable data object which can be update only based on user action https://redux.js.org/basics/store/.
Another simple but not efficient way is to use the react native async storage, Where you store the object and later load it up in the componentDidMount() of your new component.
Another way is to pass these props as ScreenProps in your child component(this is only possible if the screens have a parent child relation)
solution - Sharing the object between components using asnc storage
import AsyncStorage from '#react-native-community/async-storage';
const storeService = {
async saveItem(key, value) {
try {
await AsyncStorage.setItem(key, value);
} catch (error) {
console.log('AsyncStorage Error: ' + error.message);
}
},
loadKey(key) {
return new Promise((resolve, reject) => {
AsyncStorage.getItem(key)
.then(res => {
resolve(res)
})
.catch(err => reject(err));
});
}
};
export default storeService;
Note that these stateless component has 2 methods, One is to save against a key and another is to load.
Now to save a value against a key use
import React,
{ Component } from 'react';
....
export default class Example extends Component {
constructor(props) {
super(props);
....
}
....
render() {
...
if (this.state.visibleModal === 3) {
const { givenName } = this.state.azureLoginObject;
const { userPrincipalName } = this.state.azureLoginObject;
//this is how we will store the value when this component Example loads
storeService.saveItem('userPrincipalName', userPrincipalName)
return (
....
);
}
return (
<PlacesNavigator />
);
}
}
And to load this item again use
import React, { Component } from "react";
...
export default class MainScreen extends Component {
constructor(props) {
super(props);
this.state = {
userPricipalName: null //initialize this state variable
data: []
};
}
getData = () => {
...
var userPrincipalName = this.state.userPrincipalName;
axios.get("https://harigotphat1.mekorot.co.il/ConfirmPackaotWS/OrderApprove/OrderApp_Get_Orders_To_Approve/"+userPrincipalName.split('#')[0])
....
}
componentDidMount() {
// now we load the data we stored in the async storage
storeService.loadKey('userPrincipalName').then((res) => {
this.setState({userPricipalName: res}) //store like this
})
this.getData()
}
...
render() {
....
return (
....
);
}
}
Note that in order to be able to save a whole object in async store you will first need to stringify the object which storing and json parse while reading it again.
Really simple question, why isn't onSubmitEditing firing when I hit 'Search' on the virtual keyboard?
Currently there are no errors thrown and the console.log in onSearch() never fires.
I'm using the EXPO SDK v.29.
import React from 'react';
import { StyleSheet, Text, View, TextInput, ScrollView, Image } from 'react-native';
import { WebBrowser } from 'expo';
import Icon from 'react-native-vector-icons/Ionicons';
import Styles from 'app/constants/Styles';
import Vars from 'app/constants/Vars';
import Menu from 'app/components/Menu';
import MiniMap from 'app/components/MiniMap';
import NewsList from 'app/components/NewsList';
import {get, post} from 'app/helpers/api';
export default class HomeScreen extends React.Component {
static navigationOptions = ({ navigation }) => {
return {
headerTitle: (<Image style={{width: 132, height: 30}} source={require('./../../assets/images/header_image.png')}/>)
};
};
constructor(props) {
super(props);
this.state = {
menu: [],
loadingMenu: true,
searchString: '',
};
}
onMenuPress = (item) => {
let next;
let route = item.page_type.slice(4);
if(route == "PageExternal") {
WebBrowser.openBrowserAsync(item.page.url);
} else {
data = item.page;
if(item.children.length > 0) {
route = 'Menu';
data = item.children;
}
this.props.navigation.navigate(route, {
data: data,
title: item.title
});
}
}
onSearch = (e) => {
console.log('onSearch', e);
//WebBrowser.openBrowserAsync('https://www.1177.se/Halland/Sok/?q=Diabetes&submitted=true');
}
async componentDidMount() {
console.log('Eat my shorrs');
menuitems = await get('content/menu');
this.setState({
menu: menuitems,
loadingMenu: false,
})
//this._getMenu();
}
render() {
return (
<ScrollView style={Styles.whiteBackground}>
<View style={[Styles.blueBackground, Styles.topPadding, Styles.horizontalPadding]}>
<View style={[Styles.searchBox, Styles.bottomMargin]}>
<View style={Styles.searchField}>
<TextInput
style = {Styles.searchInput}
placeholder = "Sök sjukdom/behandling"
onSubmitEditing = {(e) => (this.onSearch(e))}
underlineColorAndroid = "transparent"
returnKeyLabel = "Sök på 1177"
returnKeyType = "search"
/>
<Icon style = {Styles.searchIcon} name = "ios-search" size={18}/>
</View>
<Text style={[Styles.searchLabel]}>Söksvaren kommer från 1177.se</Text>
</View>
<Menu
data={this.state.menu}
loading={this.state.loadingMenu}
style={Styles.topPadding}
onItemPress={this.onMenuPress}
/>
</View>
<Text style={[Styles.h1, Styles.blackText, Styles.horizontalPadding]}>Hitta till oss</Text>
<MiniMap navigation={this.props.navigation}></MiniMap>
<Text style={[Styles.h1, Styles.blackText, Styles.horizontalPadding]}>Nyheter</Text>
<NewsList navigation={this.props.navigation}></NewsList>
</ScrollView>
);
}
}
<TextInput
onSubmitEditing = {(event) => (this.onSearch(event.nativeEvent.text))}
multiline={false}
/>
It does not work when multiline={true} is specified, perhaps your styles has that. See Documentation
You will find your text with event.nativeEvent.text
Try changing
onSubmitEditing = {(e) => (this.onSearch(e))}
to
onSubmitEditing = {this.onSearch}
Then keep
onSubmitEditing = {(e) => this.onSearch(e)}
like this and try by changing the function like below
function onSearch(e) {
console.log('onSearch', e);
//WebBrowser.openBrowserAsync('https://www.1177.se/Halland/Sok/?q=Diabetes&submitted=true');
}
Hope this will work
Check this out
https://snack.expo.io/#raajnadar/submit-text-input
Render method
render() {
return (
<View style={styles.container}>
<TextInput
placeholder="Sök sjukdom/behandling"
onSubmitEditing={this.onSearch}
underlineColorAndroid="transparent"
returnKeyLabel="Sök på 1177"
returnKeyType="search"
style={{ width: '100%', textAlign: 'center' }}
/>
</View>
);
}
On submit function
onSearch() {
console.log('onSearch')
}
I am attempting to follow the React Native docs on accessing the Camera Roll. I have tried wrapping the camera roll images in a Modal Component. When I press the 'Open Camera Roll' button, the Modal comes up from the bottom with the 'close modal' button visible but none of the images from the camera roll.
When I didn't have it wrapped in a Modal, the images would appear but they would ruin the layout of all the components on my screen, which is why I am (unsuccessfully) trying to place it in a Modal.
Also, if you could give me some tips on how to make the images selectable and appear with 3 images/row it would be greatly appreciated.
import React from 'react';
import { CameraRoll, Image, Modal, ScrollView, Text, View } from 'react-native';
import { Button } from 'react-native-elements';
export default class AddEvent extends React.Component {
constructor(props){
super(props)
this.state = {
modalVisible: false,
photos: [],
}
}
getPhotos = () => {
CameraRoll.getPhotos({
first: 100,
})
.then(r => this.setState({ photos: r.edges }))
.catch((err) => {
alert('Error loading camera roll');
return;
});
}
openModal() {
this.getPhotos();
this.setState({modalVisible:true});
}
closeModal() {this.setState({modalVisible:false});}
static navigationOptions = ({ navigation }) => {
return {
headerTitle: (<Text>Camera Roll Test</Text>),
}
};
render(){
return (
<View>
<Modal
visible={this.state.modalVisible}
animationType={'slide'}
onRequestClose={() => this.closeModal()}>
<ScrollView>
{this.state.photos.map((p, i) => {
return (
<Image
key={i}
style={{width: 300, height: 100,}}
source={{ uri: p.node.image.uri }}/>
);
})}
</ScrollView>
<Button
onPress={() => this.closeModal()}
title="Close modal"/>
</Modal>
<Button
onPress={() => this.openModal()}/>
</View>
);
}
}
Got it, needed flex: 1 for <ScrollView> style and a contentContainerStyle. Doesn't look great but the photos show. Credit to u/Mingli91 on reddit.
import React from 'react';
import { CameraRoll, Image, Modal, ScrollView, StyleSheet, Text, View } from 'react-native';
import { Button } from 'react-native-elements';
const Dimensions = require('Dimensions');
const window = Dimensions.get('window');
const screenWidth = window.width;
const screenHeight = window.height;
export default class AddEvent extends React.Component {
constructor(props){
super(props)
this.state = {
modalVisible: false,
photos: [],
}
}
getPhotos = () => {
CameraRoll.getPhotos({
first: 100,
})
.then(r => this.setState({ photos: r.edges }))
.catch((err) => {
alert('Error loading camera roll');
return;
});
}
openModal() {
this.getPhotos();
this.setState({modalVisible:true});
}
closeModal() {this.setState({modalVisible:false});}
static navigationOptions = ({ navigation }) => {
return {
headerTitle: (<Text>Camera Roll Test</Text>),
}
};
render(){
return (
<View>
<Modal style={styles.modal}
visible={this.state.modalVisible}
animationType={'slide'}
onRequestClose={() => this.closeModal()}>
<ScrollView style={{flex: 1}}
contentContainerStyle={{ height: 100, width: 300 }}>
{this.state.photos.map((p, i) => {
return (
<Image
key={i}
style={{width: 300, height: 100,}}
source={{ uri: p.node.image.uri }}/>
);
})}
</ScrollView>
<Button
onPress={() => this.closeModal()}
title="Close modal"/>
</Modal>
<Button
onPress={() => this.openModal()}/>
</View>
);
}
}
const styles = StyleSheet.create({
modal: {
flex: 1,
alignItems: 'center',
width: screenWidth,
height: screenHeight,
}
});
Android 10
If you started noticing this on Android 10, try adding this to your AndroidManifest.xml:
<application
...
android:requestLegacyExternalStorage="true" />
Android is moving to "scoped storage". They started using this in Android 10, with the option to opt-out by adding android:requestLegacyExternalStorage="true" to your AndroidManifest.xml file.
However, starting in Android 11, this is a forced change and your value of android:requestLegacyExternalStorage will be ignored.
Read more here:
https://developer.android.com/training/data-storage/use-cases#opt-out-scoped-storage
Posting here because that was the issue with us and it surprisingly difficult to find out about.
I have a component for listing items, I want to add the function that can go to a different page, and that page has the detail about that item. Currently, this is my code for listing items.
import React, { Component } from 'react';
import { ScrollView } from 'react-native';
import axios from 'axios';
import CarDetail from './CarDetail';
const API_URL = 'http://localhost:3000';
class CarList extends Component {
state = { cars: [] };
componentWillMount() {
console.log('Mount');
axios.get(`${API_URL}/cars`)
.then(response => this.setState({ cars: response.data.cars }));
}
renderCars() {
return this.state.cars.map(car => <CarDetail key={car.id} car={car} />
);
}
render() {
console.log(this.state.cars);
return (
<ScrollView>
{this.renderCars()}
</ScrollView>
);
}
}
export default CarList;
and this is the code for describing items
import React from 'react';
import { Text, View, Image } from 'react-native';
import { Actions } from 'react-native-router-flux';
import Card from '../material/Card';
import CardSection from '../material/CardSection';
const CarDetail = ({ car }) => {
const imageURI = 'https://yt3.ggpht.com/-HwO-2lhD4Co/AAAAAAAAAAI/AAAAAAAAAAA/p9WjzQD2-hU/s900-c-k-no-mo-rj-c0xffffff/photo.jpg';
const { make, model } = car;
function showCarDetail() {
Actions.showCar();
}
return (
<Card>
<CardSection>
<View style={styles.containerStyle}>
<Image
style={styles.imageStyle}
source={{ uri: imageURI }}
/>
</View>
<View style={styles.headContentStyle}>
<Text
style={styles.headerTextStyle}
onPress={showCarDetail()}
>
{make}
</Text>
<Text>{model}</Text>
</View>
</CardSection>
<CardSection>
<Image
style={styles.picStyle}
source={require('./car.jpg')}
/>
</CardSection>
</Card>
);
};
const styles = {
headContentStyle: {
flexDirection: 'column',
justifyContent: 'space-around'
},
headerTextStyle: {
fontSize: 18
},
imageStyle: {
height: 50,
width: 50
},
containerStyle: {
justifyContent: 'center',
alignItems: 'center',
marginLeft: 10,
marginRight: 10
},
picStyle: {
height: 300,
flex: 1,
width: null
}
};
export default CarDetail;
How can I change my code for that? Can anyone give me an example?
You have to use some sort of navigation component. There are many out there, but personally I use the one that is built into React Native. https://facebook.github.io/react-native/docs/navigator.html