Develop Reference

Add BackgroundImage to ScrollView in React-Native for JavaScript

I have this <ScrollView />
<ScrollView
style={styles.scrollview}>
{route.params && route.params....map((cat, index) => {
return <Kitten
cat={cat}
key={index} />
})}
</ScrollView >
const styles = StyleSheet.create({
scrollview: {
paddingLeft: 15,
paddingRight: 15,
backgroundColor: 'white',
flex: 1,
},
});
into which I want to put this <BackgroundImage />.
import { ImageBackground } from 'react-native';
const image = require('...')
const Kittens = ({ children }) => {
return <ImageBackground
source={image}
resizeMode='repeat'
style={{ width: '100%', height: '100%' }}>
{children}
</ImageBackground>
}
I want the background image to be fixed, so that the content scrolls over the image. I further shall fill the whole screen. How would I do that?

use the scrollview as the child of ImageBackground
<ImageBackground
source={{uri://image url here}}
style={{
}}
>
<ScrollView
style={styles.scrollview}
contentContainerStyle={}
>
{route.params && route.params....map((cat, index) => {
return <Kitten cat={cat} key={index} />
})}
</ScrollView >
</ImageBackground>

If the parent of the Kittens fills the screen, removing white backgroundColor should work. You can play with resizeMode to get the best result from your image.
<Kittens>
<ScrollView
style={styles.scrollview}>
{route.params && route.params....map((cat, index) => {
return <Kitten cat={cat} key={index} />
})}
</ScrollView >
</Kittens>
const styles = StyleSheet.create({
scrollview: {
paddingLeft: 15,
paddingRight: 15,
//backgroundColor: 'white',
flex: 1,
},
});

<ImageBackground
source={{uri:image url}}
style={{height:"100%", width:"100%"}}
>
<ScrollView
contentContainerStyle={flexGrow:1}
>
<View style={{flex:1}} >
</View>
</ScrollView >
</ImageBackground>

Page slider not working On Android, works fine in iOS

The code below shows how all the functions are implemented
On iOS everything works fine, the button changes slide, the dots on the bottom change state based on the page and on the last page it displays a signup button,
On Android, the button works only on the first page, the last page doesnt show the signup button, and next button doesnt work on the second page!
export default function introScreen({ navigation }) {
const [sliderState, setSliderState] = useState({ currentPage: 0 });
const scrollRef = useRef();
const { width, height } = Dimensions.get('window')
const notchSize = StatusBar.currentHeight
const setSliderPage = (event: any) => {
const { currentPage } = sliderState;
const { x } = event.nativeEvent.contentOffset;
const indexOfNextScreen = Math.floor(x / width);
if (indexOfNextScreen !== currentPage) {
setSliderState({
...sliderState,
currentPage: indexOfNextScreen,
});
}
};
const { currentPage: pageIndex } = sliderState;
const onPressTouch = () => {
scrollRef.current?.scrollTo({
x: width*(pageIndex+1),
animated: true,
});
}
return (
<>
<StatusBar hidden />
<SafeAreaView style={{ flex: 1, backgroundColor:'black' }}>
<ScrollView
style={{ flex: 1 }}
horizontal={true}
scrollEventThrottle={16}
pagingEnabled={true}
showsHorizontalScrollIndicator={false}
onScroll={(event: any) => {
setSliderPage(event);
}}
ref={scrollRef}
>
<View style={{ width, height, alignItems: 'center', }}>
<Image source={require('../../assets/images/Intorduction/1.png')} style={styles.imageStyle} />
<BlurView tint={'dark'} intensity={70} style={{width:'80%',borderRadius:10, marginTop:10}}>
<Text style={[styles.textStyle,{color:'rgb(255, 190, 46)'}]}bla bla</Text>
</BlurView>
</View>
<View style={{ width, height, alignItems: 'center' }}>
<Image source={require('../../assets/images/Intorduction/2.png')} style={styles.imageStyle} />
<BlurView tint={'dark'} intensity={70} style={{width:'80%',borderRadius:10, marginTop:10}}>
<Text style={[styles.textStyle,{color:'rgb(255, 190, 46)'}]}>bla bla</Text>
</BlurView>
</View>
<View style={{ width, height, alignItems: 'center' }}>
<Image source={require('../../assets/images/Intorduction/3.png')} style={styles.imageStyle} />
<BlurView tint={'light'} intensity={70} style={{width:'80%',borderRadius:10, marginTop:10}}>
<Text style={[styles.textStyle,{color:'rgb(241, 250, 238)'}]}>bla bla</Text>
</BlurView>
</View>
</ScrollView>
{pageIndex != 2 ?
<View style={styles.paginationWrapper}>
{Array.from(Array(3).keys()).map((key, index) => (
<View style={[styles.paginationDots, { opacity: pageIndex === index ? 1 : 0.2 }]} key={index} />
))}
</View>
:
<></>
}
{pageIndex != 2 ?
<BlurView tint={'dark'} intensity={70} style={styles.nextButton}>
<TouchableOpacity style={{flex:1, justifyContent:'center', alignItems:'center'}} onPress={onPressTouch} >
<Text style={{color:'rgb(241, 250, 238)',fontFamily: 'poiret-one', fontSize:25}}>
Next
</Text>
</TouchableOpacity>
</BlurView>
:
<BlurView tint={'light'} intensity={70} style={styles.signUpButton}>
<TouchableOpacity style={{flex:1, justifyContent:'center', alignItems:'center'}} onPress={() =>navigation.navigate('Login')} >
<Text style={{color:'black',fontFamily: 'poiret-one', fontSize:25}}>
Sign Up
</Text>
</TouchableOpacity>
</BlurView>
}
</SafeAreaView>
</>
);
}

I have narrowed down the problem to the width and the 'event.nativeEvent.contentOffset', the returning number is close to 1 but it is (0.9), therefor math.floor was giving 0 as the index number,
I have changed Math.floor to Math.round and it is working perfectly fine,
If anyone wants a Introduction Slider for their app they can use this

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.

Not able to access the absolute position view in react-native android

I have a component called MDropDowlList which render the following view :
MDropDownList.js
render() {
return (
<View>
<View
style={{
backgroundColor: '#fff',
position: 'absolute',
left: 0,
right: 0,
top: 0,
maxHeight: 200,
}}
>
{
this.props.searchable && (
<TextInput
style={{ zIndex: 198 }}
onChangeText={(text) => this.search(text)}
/>
)
}
<FlatList
data={this.state.data}
keyboardShouldPersistTaps="always"
nestedScrollEnabled={true}
contentContainerStyle={{ zIndex: 199 }}
keyExtractor={(item, index) => index.toString()}
renderItem={({ item, index }) => (
<TouchableHighlight
key={index.toString()}
style={{
padding: 10,
backgroundColor: '#fff',
}}
underlayColor="#5897fb"
onPress={() => this.props.handleOnPress(item)}
>
<MText size={18}>{item}</MText>
</TouchableHighlight>
)}
/>
</View>
</View>
);
}
Then I have called this component to another component called MDropDown which render method is as below :
MDropDown.js
render() {
return (
<View style={{ marginVertical: 5, zIndex: 3}}>
...
{/* Another components */}
...
{
this.state.displayDropDown && (
<MDropDownList data={this.props.data} searchable={this.props.searchable} handleOnPress={(item) => this.handleOnPress(item)} />
)
}
</View>
);
}
Now finally I called my MDropDown component in my main screen as follow :
render() {
return (
<KeyboardAvoidingView style={{ flex: 1, backgroundColor: Colors.bgGray }} behavior="padding">
<ScrollView showsVerticalScrollIndicator={false} contentContainerStyle={styles.container} keyboardShouldPersistTaps="always" nestedScrollEnabled={true}>
<View style={{ backgroundColor: '#fff', padding: 10 }}>
<MDropDown
label="Category"
placeholder="Select Category"
data={["test1", "test2", "test3", "test4", "test5"]}
onSelectItem={(selectedItem) => alert(selectedItem)}
searchable={true}
/>
</View>
</ScrollView>
</KeyboardAvoidingView>
)
}
But I am not able to access Flatlist item or TextInput of MDropDownList component. Even I am not able to focus TextInput available in MDropDownList.
Please help me what's going wrong here ???
Note : This issue is only on android, on ios it is working properly. On ios I am able to click flatlist item and focus TextInput as well as.

Tried using zIndex to the absolute view?
Add property of zIndex : 500 to the style.

how to render a different component after every iteration of map function

I am fetching data from http://retailsolution.pk/api/allhome I want to display the title of the product and then all the child products below it, I am getting this output: Here's my code:
class App extends Component {
constructor(props) {
super(props);
this.state = {
Deals: []
};
}
componentWillMount() {
axios
.get("https://retailsolution.pk/api/allhome")
.then(response => this.setState({ Deals: response.data.Deals }));
}
_renderItem(item) {
return (
<View style={{ width: 100, height: 130 }}>
<Image
style={{ width: 100, height: 100 }}
source={{ uri: item.image }}
/>
<Text numberOfLines={1} style={{ flex: 1 }}>
{" "}
{item.name}
</Text>
</View>
);
}
renderTitle() {
return this.state.Deals.map(deal => (
<Text key={deal.parent.id} style={styles.text}>
{deal.parent.name}
</Text>
));
}
renderImage() {
return this.state.Deals.map(deal => (
<FlatList
key={deal.child.product_id}
style={{ marginTop: 5 }}
horizontal
ItemSeparatorComponent={() => <View style={{ width: 5 }} />}
renderItem={({ item }) => this._renderItem(item)}
data={[deal.child]}
/>
));
}
render() {
console.log(this.state.Deals);
return (
<View style={{ flex: 1, marginLeft: 8, marginRight: 8, marginTop: 10 }}>
{this.renderTitle()}
{this.renderImage()}
</View>
);
}
}
In my case {this.renderTitle()} gets execute first and maps every value from the api to the app and then {this.renderImage()} maps all flatlists to the app.
Is there any way I can run this.renderImage() after every iteration of rhis.renderTitle()?

You will have to do it using nested loop.
Try something like this -
{this.state.Deals.map(deal => {
return (
<div>
<Text key={deal.parent.id} style={styles.text}>
{deal.parent.name}
</Text>
{deal.child.map(item => {
return (
<FlatList
key={item.product_id}
style={{ marginTop: 5 }}
horizontal
ItemSeparatorComponent={() => <View style={{ width: 5 }} />}
renderItem={({ item }) => this._renderItem(item)}
data={[item]}
/>
);
})}}
</div>
);
})}

A way to do it is to call a function after the fetch that will create the section data for the Flatlist with the correct format:
sections = [{title: 'Latest', data:["The products data array"]}, {title: 'second section', data : ["Other products"]}, and so on...]`