How can i get the index of Scrollview item React-native? - react-native

this is my custom component code here..
const Item = (props) => {
if (props.isFake) {
return null
}
return (
<TouchableOpacity onPress={props.onPress} style={styles.listItemParent}>
{/*<Text style={styles.listItemText}> {props.index} </Text>*/}
<Text style={styles.listItemText}> {props.title} </Text>
<Text style={styles.listItemURL}> {props.url} </Text>
{/*<Text>{props.lead}</Text>*/}
</TouchableOpacity>
)
};
and i render it like that...
<ScrollView>
{this.state.items.map(item => <Item onPress={ (index)=> this.onclick(index)} {...item} />) }
</ScrollView>
How can i get the index of 'item'?

.map returns the value and the index :)
<ScrollView>
{this.state.items.map((item,i) => <Item onPress={ ()=> this.onclick(i)} {...item} />) }
</ScrollView>

Related

Giving props to other component React Native not working

I'm trying to give the data of a certain person to the other component but for some reason this only gives errors.
I tried doing that with the props method as it should but that does not work.
What can be the solution?
Parent:
export default function EditFamily({ navigation, props, person, inheritors }) {
const [shouldShowAdd, setShouldShowAdd] = useState(null);
const [shouldShowAddChild, setShouldShowAddChild] = useState(null);
function renderFamily(family, key) {
return (
<View key={key} style={styles.family}>
<View style={styles.inheritors}>
{family.inheritors.map((inheritor) => {
return (
<Add
key={inheritor.id}
person={inheritor}
setShouldShowAdd={setShouldShowAdd}
/>
);
})}
</View>
{family.children && family.children.length ? (
<View style={styles.children}>
{family.children.map((child, index) => renderFamily(child, index))}
</View>
) : null}
</View>
);
}
return (
<View style={styles.container}>
<SafeAreaView style={styles.container}>
{shouldShowAdd ? (
<View style={styles.details}>
<View style={styles.pressView}>
<Pressable
onPress={() => setShouldShowAdd(null)}
style={styles.pressX}
>
<Text>X</Text>
</Pressable>
</View>
<Pressable>
<Text>Edit date of {shouldShowAdd.firstname}</Text>
</Pressable>
<Pressable
onPress={() => setShouldShowAddChild(!shouldShowAddChild)}
>
<Text>Add child</Text>
</Pressable>
{shouldShowAddChild && <AddChild />}
<Pressable>
<Text>Add Partner</Text>
</Pressable>
<Pressable>
<Text>Add Parent</Text>
</Pressable>
</View>
) : null}
<ScrollView>
<ScrollView horizontal={true}>{renderFamily(data)}</ScrollView>
</ScrollView>
</SafeAreaView>
<StatusBar style="auto" />
</View>
);
}
Component that gives data to the parent:
export default function Add({ person, setShouldShowAdd }) {
let mijnFoto = 'http://192.168.1.36/CodingApp/assets/' + person.image;
return (
<TouchableOpacity
style={styles.person}
onPress={() => setShouldShowAdd(person)}
>
<Text style={styles.text}>
{person.firstname} {person.lastname}
</Text>
</TouchableOpacity>
);
}
The component that should for example be able to show the Id of the person that's been clicked:
export default function AddChild({ setShouldShowAdd }) {
return (
<View>
<Text>hoi id:{person.id}</Text>
</View>
);
}

I am not able to navigate to the other screen in my react native project the error is: navigation not found

const Item = ({ item }) => (
<TouchableOpacity
onPress={() => this.navigation.navigate(
"carProfile",
{item: item}
)}>
<View style={styles.item}>
<Text style={styles.title}>{item.name}</Text>
<Text style={styles.details}>{item.details}</Text>
</View>
</TouchableOpacity>
);
const List = (props,navigation) => {
const renderItem = ({ item }) => {
if (props.searchPhrase === "") {
return <Item item={item} />;
}
if (item.name.toUpperCase().includes(props.searchPhrase.toUpperCase().trim().replace(/\s/g, ""))) {
return <Item item={item} />;
}
if (item.details.toUpperCase().includes(props.searchPhrase.toUpperCase().trim().replace(/\s/g, ""))) {
return <Item item={item} />;
}
};
return (
<SafeAreaView style={styles.list__container}>
<View
onStartShouldSetResponder={() => {
props.setClicked(false);
}}
>
<FlatList
data={props.data}
renderItem={renderItem}
keyExtractor={(item) => item.id}
/>
</View>
</SafeAreaView>
);
};
export default List;
the error is continuing to be there despite me trying to put navigation container in different positions. I want to send the user to the carProfile page, where the data passed in item is reused. This way user can know about the selection they are looking for
Use this way
onPress={() => this.props.navigation.navigate(
"carProfile",
{item: item}
)}
The navigation is inside the props, not as a second argument. Below is a classic example. And also note, you cannot extract navigation prop for child components, it will only work on Main components(Screens).
function HomeScreen({ navigation }) {
return (
<View style={{ flex: 1, alignItems: 'center', justifyContent: 'center' }}>
<Text>Home Screen</Text>
<Button
title="Go to Details"
onPress={() => navigation.navigate('Details')}
/>
</View>
);
}
If you want to use navigation inside child components, you can use the navigation hooks.
import { useNavigation } from "#react-navigation/native";
function MyBackButton() {
const navigation = useNavigation();
return (
<Button
title="Back"
onPress={() => {
navigation.goBack();
}}
/>
);
}

Why does FlatList scrolls to top when I select an item

I have a FlatList with TouchableOpacity items. When I try to select an item, the list scrolls to top.
This is the Collapsible content;
const setBrandSelected = index => {
var temp = JSON.parse(JSON.stringify(tempFilterOptions));
temp[0].enums[index].selected = !temp[0].enums[index].selected;
setTempFilterOptions(temp);
};
const FilterOptionBrand = () => {
const RenderBrand = ({ item, index }) => {
return (
<TouchableOpacity onPress={setBrandSelected.bind(null, index)}>
{item.selected && (
<View style={[styles.brandImage, styles.selectedBrandImage]}>
<Icon iconName={iconNames.Tick} />
</View>
)}
<FastImage source={{ uri: item.logo }} style={styles.brandImage} resizeMode={FastImage.resizeMode.contain} />
<Text style={styles.brandName}>{item.name}</Text>
</TouchableOpacity>
);
};
const BrandSeparator = () => <View style={styles.brandSeparator} />;
return (
<View style={styles.filterBrandMainContainer}>
<View style={styles.searchBrandContainer}>
<View style={styles.magnifyingGlassWrapper}>
<Icon iconName={iconNames.MagnifyingGlass} />
</View>
<TextInput style={styles.searchBrandInput} placeholder={searchBrandText} />
</View>
<FlatList
horizontal={true}
showsHorizontalScrollIndicator={false}
keyExtractor={(item, index) => String(item.id)}
style={styles.collapsibleContainer}
data={tempFilterOptions[0].enums}
renderItem={RenderBrand}
ItemSeparatorComponent={BrandSeparator}
></FlatList>
</View>
);
};
If you somehow stumble upon this question. The answer is wherever the problem occurs be it Header be it Footer. You should call the component function and not directly just type the function.
const Header = () => <View />
Correct usage;
ListHeaderComponent={Header()}
Incorrect usage;
ListHeaderComponent={Header}

React Native Flatlist with radio buttons works slow

I have flatlist with custom radio buttons implementaion, but when i tap on flatlist item it waits about second before changes to active button. I tried to useCallback with my renderItem and itemKeyExtractor functions but it doesnt help me.
Here is the code of my screen component:
export const PickOrganizationScreen = (props) => {
const { navigation, setOrganization, loadProcedureProviders, items, isLoading, procedureId, organizationId } = props;
useFocusEffect(
React.useCallback(()=>{loadProcedureProviders(procedureId);},[loadProcedureProviders, procedureId])
);
const renderItem = ({item}) => {
return (
<OrganizationItem
title={item.Title}
checked = {item.Id === organizationId}
onPress={() => {
setOrganization(item.Id, item.Title);
}}
/>);
};
const itemKeyExtractor = (item) => item.Id;
return (
isLoading ? (
<Spinner />
) : (
items.length > 0 ? (
<View style={styles.container}>
<View style={styles.paragraph}>
<Text style={styles.subtitle}>{I18n.t('pickOrganization')}</Text>
</View>
<View style={styles.alertMessage}>
<View style={styles.alertIcon}>
<Icon name="info" width={32} height={32} fill={Colors.primaryRed} />
</View>
<View>
<Text style={styles.alertText}>{I18n.t('pickOrganizationToRegisterService')}</Text>
</View>
</View>
<FlatList
data = {items}
renderItem = {renderItem}
keyExtractor = {itemKeyExtractor}
extraData={organizationId}
/>
<View style={styles.buttonWrapper}>
<ScreenButton
title={I18n.t('goToRegister')}
onPress={ () => {
navigation.navigate('ServiceSummary');
}}/>
</View>
</View>
) : (
<NotFound extraText={I18n.t('notFoundExtra')}/>
)
)
);
};
Here is the code of flatlist item component:
export const OrganizationItem = ({title, checked, onPress}) => {
return (
<TouchableOpacity onPress={onPress}>
<View style={styles.itemContainer}>
<View style={styles.itemIcon}>
{ checked ? (
<Icon name="radio-button-on" width={16} height={16} fill={Colors.primaryRed} />
) :
(
<Icon name="radio-button-off" width={16} height={16} fill={Colors.gray} />
)
}
</View>
<View style={styles.itemText}>
<Text style={styles.title}>{title}</Text>
</View>
</View>
</TouchableOpacity>
);
};
Try memoizing OrganizationItem. Does the onPress in OrganizationItem change the items object ? If so, it will re-render the whole Flatlist even when one small change is made. If you memoize, the components memoized won't rerender unless the props passed to it changes.
export const OrganizationItem = React.memo(({title, checked, onPress}) => {
return (
<TouchableOpacity onPress={onPress}>
<View style={styles.itemContainer}>
<View style={styles.itemIcon}>
{ checked ? (
<Icon name="radio-button-on" width={16} height={16} fill={Colors.primaryRed} />
) :
(
<Icon name="radio-button-off" width={16} height={16} fill={Colors.gray} />
)
}
</View>
<View style={styles.itemText}>
<Text style={styles.title}>{title}</Text>
</View>
</View>
</TouchableOpacity>
);
});

React Native FlatList Delete Item

I want to delete item from the FlatList. However, the solution from here is not working for my code. When I run my code, I am getting error such as 'index is not defined'.
I have yet to find other post regarding this issue so any help would be greatly appreciated.
Code snippet provided below:
export default class FrCreateScreen extends Component {
constructor(props) {
super(props);
this.state = {
//new timeSlots
timeSlots: [],
}
}
setEndTime = (event, appointmentEndTime, textEndTime) => {
appointmentEndTime = appointmentEndTime || this.state.appointmentEndTime;
textEndTime = textEndTime || moment(appointmentEndTime).format('h:mm a').toString();
this.setState({
showEndTime: Platform.OS === 'ios' ? true : false,
appointmentEndTime,
textEndTime,
timeSlots: [
...this.state.timeSlots,
{
apptdate: this.state.textAppointmentDate,
appttime: this.state.textAppointmentTime,
endTime: textEndTime,
}
],
});
}
deleteDateTime = (id) => {
const filteredData = this.state.timeSlots.filter(item => item.id !== id);
this.setState({ timeSlots: filteredData });
}
render() {
return (
<ScrollView>
...
<View>
<FlatList
data={this.state.timeSlots}
keyExtractor={({ id }, index) => index.toString()}
renderItem={({ item }) => {
return (
<View style={styles.containerList}>
...
<TouchableOpacity onPress={() => this.deleteDateTime(index)}>
<Feather name="trash" style={styles.icon} />
</TouchableOpacity>
</View>
</View>
);
}}
/>
</View>
</ScrollView>
)
};
};
Screenshot below:
I think you need to add index inside renderItem { item, index }
renderItem = {({ item, index }) => {
return (
<View style={styles.containerList}>
<TouchableOpacity onPress={() => this.deleteDateTime(index)}>
<Feather name="trash" style={styles.icon} />
</TouchableOpacity>
</View>
);
}}
While rendering in map function , it provides the index too, so try adding that.
renderItem={({ item,index }) => {
return (
<View style={styles.containerList}>
...
<TouchableOpacity onPress={() => this.deleteDateTime(index)}>
<Feather name="trash" style={styles.icon} />
</TouchableOpacity>
</View>
</View>
);
}}
Hope it helps
ok fixed. on touchable onPress, the argument should be 'item.index' instead of 'index'.
here's the correct code:
renderItem={({ item,index }) => {
return (
<View style={styles.containerList}>
...
<TouchableOpacity onPress={() => this.deleteDateTime(item.index)}>
<Feather name="trash" style={styles.icon} />
</TouchableOpacity>
</View>
</View>
);
}}