Develop Reference

Automatically scroll ScrollView in KeyboardAvoidingView when I add a new TextInput

I am working with a KeyboardAvoidingView and it's working perfectly fine except for one small issue. In the code below I have a TouchableOpacity that when clicked runs the function addName() which appends to an array and creates a new TextInput - basically when you click it, it adds a new TextInput to the ScrollView.
The KeyboardAvoidingView works perfectly fine except every time a new TextInput is added/rendered, I have to scroll down to see it. Do you know how I can make it automatically scroll to the bottom when a new TextInput is rendered?
Here is my code for the KeyboardAvoidingView:
<KeyboardAvoidingView
style={styles.container}
behavior={Platform.OS == "ios" ? "padding" : "height"}
>
<HeaderComponent
name={this.props.route.params.bill.barName + " Tab"}
navigation={this.props.navigation}
goHome={true}
goHomePrompt={true}
/>
<View
style={{
marginTop: 30,
marginLeft: 10,
}}
>
<Text
style={{ color: "white", fontSize: 18 }}
allowFontScaling={false}
>
Add people to split with...
</Text>
</View>
<ScrollView keyboardShouldPersistTaps={"handled"}>
{this.state.nameInput.map((value, index) => (
<View style={styles.nameContainer} key={index}>
<View
style={{
width: "90%",
}}
>
<TextInput
style={styles.textInputContainer}
value={value}
onChange={this.handleText(index)}
placeholder={"Enter name..."}
placeholderTextColor={"#333333"}
maxLength={50}
/>
</View>
<View
style={{
width: "10%",
}}
>
<TouchableOpacity
onPress={() => this.handleDelete(index)}
>
<Icon name="cancel" type="material" color="red" />
</TouchableOpacity>
</View>
</View>
))}
<TouchableOpacity onPress={() => this.addName()}>
<Text style={styles.addPerson}>+ Add Person</Text>
</TouchableOpacity>
</ScrollView>
<View style={styles.bottomContainer}>
<TouchableOpacity
style={styles.continueButton}
onPress={() => {
// filters through array to make sure there are no empty strings
let nameInput = this.state.nameInput.filter(
(name) => name !== ""
);
if (
nameInput.length > 1 &&
new Set(nameInput).size === nameInput.length
) {
this.setState({ nameInput, loading: false });
} else {
alert(
"Please make sure there are at least two people and no duplicate names!"
);
}
}}
>
<Text style={styles.continueButtonText} allowFontScaling={false}>
Continue to Split Tab
</Text>
</TouchableOpacity>
</View>
</KeyboardAvoidingView>
And here is my code for the addName() function:
addName = () => {
let nameInput = this.state.nameInput.concat("");
this.setState({
nameInput,
});
};

This page has the solution I was looking for: Is it possible to keep a ScrollView scrolled to the bottom?

Different content on React Native based on condition

on my react-native app I would like to have premium content for people who paid a subscription.
My issue is how I make the content to display as unavailable(if you are not premium ) and the same as the other content if you are premium. Basically I would like the premium content to be displayed with a "lock overlay" on it for non-premium users.
However, I do not know how I set this conditional. It is a matter of state? If yes where should be positioned this state considering that is unidirectional?
Just to be clear I will have premium and non premium content
class Browser extends Component {
scrollX = new Animated.Value(0);
renderRecommended = () => {
return (
<View style={[styles.flex, styles.column, styles.recommended]}>
<View style={[styles.row, styles.recommendedHeader]}>
<Text
style={{
fontSize: theme.sizes.font * 1.4,
alignSelf: 'center',
color: 'white',
fontFamily: 'Nunito-Bold',
}}>
Recommended
</Text>
</View>
<View style={[styles.column, styles.recommendedList]}>
<FlatList
horizontal
scrollEnabled
showsHorizontalScrollIndicator={false}
scrollEventThrottle={16}
snapToAlignment="center"
style={[styles.shadow, {overflow: 'visible'}]}
data={this.props.destinations}
keyExtractor={(item, index) => `${item.id}`}
renderItem={({item, index}) =>
this.renderRecommendation(item, index)
}
/>
</View>
</View>
);
};
renderRecommendation = (item, index) => {
const {destinations} = this.props;
const isLastItem = index === destinations.length - 1;
const {navigation} = this.props;
return (
<TouchableOpacity
onPress={() =>
this.props.navigation.navigate('PreScreen', {
item,
})
}>
<View
style={[
styles.flex,
styles.column,
styles.recommendation,
styles.shadow,
index === 0 ? {marginLeft: theme.sizes.margin} : null,
isLastItem ? {marginRight: theme.sizes.margin / 2} : null,
]}>
<ImageBackground
style={[styles.imageback]}
source={{uri: item.preview}}
/>
</View>
<View
style={[
index === 0 ? {marginLeft: theme.sizes.margin - 10} : null,
isLastItem ? {marginRight: theme.sizes.margin / 2} : null,
]}>
<Text
style={{
fontSize: theme.sizes.font * 1.25,
fontWeight: '200',
color: 'white',
marginLeft: 10,
//paddingBottom: 20,
fontFamily: 'Nunito-Bold',
}}>
{item.title}
</Text>
<Text
style={{
color: theme.colors.caption,
marginLeft: 10,
fontFamily: 'Nunito-SemiBold',
}}>
{item.location}
</Text>
</View>
</TouchableOpacity>
);
};
render() {
return (
<ScrollView style={styles.container}>
<BackgroundSvg style={styles.background} />
<ScrollView
style={styles.contentContainer}
showsVerticalScrollIndicator={false}
contentContainerStyle={{paddingBottom: theme.sizes.paddin}}>
{this.renderRecommended()}
{this.renderRecommended2()}
{/* <View style={styles.mainContainerView}>
<TouchableOpacity style={styles.singInButton} gradient>
<Text style={styles.logInText}>
Activate premium subscription
</Text>
</TouchableOpacity>
</View> */}
</ScrollView>
</ScrollView>
);
}
}
Browser.defaultProps = {
destinations: mocks,
reading: readingList,
};
export default Browser;
My code is the one on the top. Just to simplify I am accesing some elements from JSON and I am creating Flatlist based on this. What I want is is to give some of the JSON files a bolean with premium or not and in this way to make some elements available for user or not.

As part of your destinations array, for each object, you can specify a boolean field called isPremiumItem. Your users should have a boolean field like isPremiumUser to show the type of their subscription.
Then in renderRecommended method you can check the user subscription status (isPremiumUser), and also the specific item status (isPremiumItem). Then you can render accordingly.

Animate the dynamic height of a view on scroll

I have a UI similar to the image below:
The Title section (the section in dark blue) is supposed to be fixed and the Body section is scrollable.
The height of the Title section would be dynamic as there can be 4 - 5 bullet points retrieved from the server.
My task is to start reducing the height of the Title section when the user starts scrolling upwards to read the content that's present beneath until the point where the user can only read the title in the header. Also, when the user starts scrolling downwards to the point where he/she can see the heading Body, I am supposed to start increasing the height so that he can again start seeing all the bullet points.
This feature is more of like hiding/showing the header on the scroll. But, the title will always be visible.
I have written the below-written code to achieve the same:
import React from 'react';
import {
View,
Text,
ScrollView,
TouchableOpacity,
Linking,
Image,
Animated,
} from 'react-native';
class App extends React.PureComponent<Props, States> {
constructor() {
super();
this.state = {
headerHeight: 0,
headerTitleHeight: 0,
};
this.scrollY = new Animated.Value(0);
}
render() {
const { navigation, pending, macroFeed } = this.props;
const { headerHeight, headerTitleHeight } = this.state;
const { themeDetails } = navigation.state.params;
const {
title, bullet1, bullet2, bullet3,
} = themeDetails;
let headerStyle = {};
if (headerHeight) {
headerStyle = {
height: this.scrollY.interpolate({
inputRange: [0, headerHeight - headerTitleHeight],
outputRange: [headerHeight, headerTitleHeight],
extrapolate: 'clamp',
}),
};
}
const sortedMacroFeed = _.sortBy(macroFeed, (o) => moment(o.date).format('YYYYMMDD')).reverse().slice(0, 5);
if (pending) {
return (
<View style={styles.maxFlex}>
<LoadingSpinner
size="large"
containerStyle={styles.loadingSpinner}
/>
</View>
);
}
return (
<View
style={styles.maxFlex}
>
<Animated.View
style={[styles.headerWrapper, headerStyle]}
onLayout={(event) => {
this.setState({
headerHeight: event.nativeEvent.layout.height,
});
}}
>
<View style={styles.macroBgWrapper}>
<Image source={themeDetails.imgUrl} style={styles.macroBg} />
<View style={styles.macroBgOverlay} />
</View>
<View
style={styles.header}
onLayout={(event) => {
this.setState({
headerTitleHeight: event.nativeEvent.layout.height,
});
}}
>
<TouchableOpacity onPress={() => navigation.goBack()}>
<View>
<Icon name="ios-arrow-back" size={32} style={styles.backIcon} />
</View>
</TouchableOpacity>
<View style={styles.titleWrap}>
<Text style={styles.headerTitle}>
{title}
</Text>
</View>
</View>
<View style={styles.bulletWrapper}>
{
!!bullet1 && (
<View style={styles.column}>
<View style={styles.row}>
<View style={styles.bullet}>
<Text style={styles.buttetListText}>
{'\u2022'}
{' '}
</Text>
</View>
<View style={styles.bulletText}>
<Text style={styles.buttetListText}>
{bullet1}
</Text>
</View>
</View>
</View>
)
}
{
!!bullet2 && (
<View style={styles.column}>
<View style={styles.row}>
<View style={styles.bullet}>
<Text style={styles.buttetListText}>
{'\u2022'}
{' '}
</Text>
</View>
<View style={styles.bulletText}>
<Text style={styles.buttetListText}>
{bullet2}
</Text>
</View>
</View>
</View>
)
}
{
!!bullet3 && (
<View style={styles.column}>
<View style={styles.row}>
<View style={styles.bullet}>
<Text style={styles.buttetListText}>
{'\u2022'}
{' '}
</Text>
</View>
<View style={styles.bulletText}>
<Text style={styles.buttetListText}>
{bullet3}
</Text>
</View>
</View>
</View>
)
}
{
!bullet1 && !bullet2 && !bullet3 && (
<View style={styles.noBulletWrapper}>
<Text style={styles.noBulletPoints}>
No description found.
</Text>
</View>
)
}
</View>
</Animated.View>
<ScrollView
style={styles.maxFlex}
showsVerticalScrollIndicator={false}
onScroll={Animated.event([
{ nativeEvent: { contentOffset: { y: this.scrollY } } },
])}
scrollEventThrottle={16}
>
<View style={[styles.section, styles.wrapGutter]}>
<Text style={styles.sectionTitle}>
Recent Headlines
</Text>
{
sortedMacroFeed.map((feed) => (
<View key={feed.id} style={styles.newsSection}>
<Text style={styles.newsHours}>
{moment(feed.date).fromNow()} | {feed.author}
</Text>
<Text style={styles.newsTitle}>
{feed.title}
<Text onPress={() => this.openWebView(feed.url)}>
<EvilIcons name="external-link" size={16} style={styles.externalLinkIcon} />
</Text>
</Text>
</View>
))
}
</View>
<View style={styles.section}>
<View style={[styles.wrapGutter, styles.sectionTitleWrap]}>
<Text style={styles.sectionTitle}>
Exposure
</Text>
<View style={styles.totalNavWrap}>
<Text style={styles.totalNav}>
$467M
</Text>
<Text style={styles.totalNavLabel}>
Total NaV (all portfolios)
</Text>
</View>
</View>
<Tabs
tabsData={TABS_DATA}
renderTabContent={this.renderTabContent}
tabName="title"
hideIfOneTab
/>
</View>
</ScrollView>
</View>
);
}
}
If you have observed I am trying to retrieve the dynamic height of the title section using onLayout.
This code only works one way i.e when I scroll up. The height of the title section reduces to the point where only the title can be seen and the bullet points get hidden. But after that, I cannot scroll down. The height gets permanently reduced.
Now, if I change the below-given code:
let headerStyle = {};
if (headerHeight) {
headerStyle = {
height: this.scrollY.interpolate({
inputRange: [0, headerHeight - headerTitleHeight],
outputRange: [headerHeight, headerTitleHeight],
extrapolate: 'clamp',
}),
};
}
to
const headerStyle = {
height: this.scrollY.interpolate({
inputRange: [0, 240],
outputRange: [300, 60],
extrapolate: 'clamp',
}),
};
everything seems to work fine. Basically, if I stop retrieving the value of the height dynamically and provide a static value like 240 or something, everything seems to work fine.
But, animation on scroll stops if I accept dynamic height. Any help to solve this would be much appreciated. Thanks in anticipation.

I found the issue. So, if you observe the line:
<Animated.View
style={[styles.headerWrapper, headerStyle]}
onLayout={(event) => {
this.setState({
headerHeight: event.nativeEvent.layout.height,
});
}}
>
onLayout used to setState as soon as the headerHeight value changed on the scroll. Due to which the height of the header used to reduce and scrolling the content down was not possible.
I changed the code to:
<Animated.View
style={[styles.headerWrapper, headerStyle]}
onLayout={(event) => {
if (!this.state.headerHeight) {
this.setState({
headerHeight: event.nativeEvent.layout.height,
});
}
}}
>
Now, everything works fine.

How to select FlatList item in React Native?

I have this code :
renderRooms = ({item:room}) => {
return(
<View style={styles.cards}>
<View style={styles.cardRight}>
<View style={{ marginLeft:2, alignItems: 'center', flex:1 }}>
<Text style={{fontSize:12, marginTop:10, marginBottom: 5, color:'#B0B0B0'}}>
Harga/malam
</Text>
<Text style={{fontSize:12, textDecorationLine:'line-through'}}>
{`${'Rp.'}${room.pricing.normal}`}
</Text>
<Text style={{fontSize:14, fontWeight:'800', color:'#26de81', }}>
{`${'Rp.'}${room.pricing.discount}`}
</Text>
<CheckBox
// center
iconRight
title={this.state.showContinueToPayment == true ? 'Batal' : 'Pilih'}
checked={this.state.showContinueToPayment}
containerStyle={{padding:5, borderColor:'white', backgroundColor:'white'}}
onPress={() => this.setState({showContinueToPayment: !this.state.showContinueToPayment})}
/>
</View>
</View>
</View>
)
}
on this part :
<CheckBox
iconRight
title={this.state.showContinueToPayment == true ? 'Batal' : 'Pilih'}
checked={this.state.showContinueToPayment}
containerStyle={{padding:5, borderColor:'white', backgroundColor:'white'}}
onPress={() => this.setState({showContinueToPayment: !this.state.showContinueToPayment})}
/>
I want to be able to set the state of my checkbox, but I can't make it done.
I'm using a FlatList, when I render my app, this renderRooms give me 2 list. I think the problem is these 2 list should have their own state. But I don't know how to do it.
Looking for some helps. Thanks beforehands.

Trying to create two columns in react-native

I am trying to create a two column grid using flex. One column will be used to display a word or phrase and the second column will be used to translate the first column. Here is a link: http://imgur.com/nZGo8pb to give you a visual idea on what I am trying to achieve.
I am unable to get two columns side by side. I am only able to have my words appear on top of each other. This is best attempt. A huge failure.http://imgur.com/a/ICApr
My code is:
nent} from 'react';
import { Text, View,StyleSheet,Image,TextInput,ListView} from 'react-native';
class AddWords extends Component{
state = {words:['iku','konkai','kaikan'],
word:'',
EnglishWords:['go','this time','next time']
}
renderList(tasks){
return(
tasks.map((task) =>{
return(
<View key={task} style={styles.item}>
<Text>
{task}
</Text>
<Text>
</Text>
</View>
)
})
)
}
renderEnglishWords(english){
return(
english.map((english) =>{
return(
<View key={english} style={styles.item2}>
<Text>
{english}
</Text>
<Text>
</Text>
</View>
)
})
)
}
addWord(){
let words = this.state.words.concat([this.state.word]);
this.setState({words})
}
render(){
return(
<View style={styles.container}>
<TextInput
style={styles.input}
onChangeText={(word) => {
this.setState({word})
}}
onEndEditing={()=>this.addWord()}
/>
<View style={styles.wordContainer}>
{this.renderList(this.state.words)}
{this.renderEnglishWords(this.state.EnglishWords)}
<View style={styles.item2}>
</View>
</View>
</View>
)
}
}
const styles = StyleSheet.create({
container:{
flex:1,
borderWidth:3,
borderColor:'green',
flexDirection:'column',
paddingTop:10
},
wordContainer:{
flexDirection: 'column',
borderColor:'blue',
borderWidth:2
},
input:{
height:60,
borderWidth:1,
borderRadius:5,
borderColor:'black',
textAlign:'center',
margin:10,
paddingTop:20,
paddingBottom:10
},
item:{
borderColor:'red',
borderWidth:2
},
item2:{
borderColor:'black',
borderWidth:2,
flexDirection:'column',
}
})
export default AddWords;
Any help will be greatly appreciated.
Thanks.

You need to wrap both inner containers in another <View> with the following style:
<View style={styles.container}>
<TextInput
style={styles.input}
onChangeText={(word) => {
this.setState({ word })
}}
onEndEditing={this.addWord}
/>
<View style={{ flexDirection: 'row', flex: 1 }}>
<View style={styles.wordContainer}>
...
</View>
<View style={styles.item2}>
...
</View>
</View>
</View>

It's because the flexDirection in styles.wordContainer is set to 'column', it should be set to 'row'.
Check out this link on flex-direction examples.