How to render component via FlatList? - javascript

Using react native with typescript and redux toolkit
Hi I'm bothering with render a list of messages via FlatList. By ScrollView everything rendering good but I need to implement infiniti scroll. So I'm doing something like this
const MessagesScreen = () => {
const companyId = useAppSelector(getCompanyId);
const userId = useAppSelector(getUserId);
const {
data: messages,
isLoading,
refetch
} = useGetMessagesQuery({ userId, companyId });
useFocusEffect(refetch);
return (
<FlatList
data={messages}
renderItem={() => {
<Messages messages={messages} />;
}}
/>
);
};
In return() I'm trying to render FlatList with component Messages which is down here:
const Messages = ({ messages }: { messages: Message[] }) => {
const navigation =
useNavigation<RootStackScreenProps<'DrawerNavigator'>['navigation']>();
const { colors } = useTheme();
return (
<View style={styles.container}>
{messages.map(message => {
const createdAt = message.created_at;
const isRead = message.read;
const icon = isRead ? 'email-open-outline' : 'email-outline';
const onClick = () => {
navigation.navigate('Message', {
messageId: message.id
});
};
return (
<TouchableOpacity key={message.id} onPress={onClick}>
<View
style={[styles.message, { borderBottomColor: colors.separator }]}
>
<View style={styles.iconPart}>
<Icon
name={icon}
type="material-community"
style={
isRead
? { color: colors.separator }
: { color: colors.inputFocus }
}
size={24}
></Icon>
</View>
<View style={styles.bodyPart}>
<Text
numberOfLines={1}
style={[isRead ? styles.readSubject : styles.unReadSubject]}
>
{message.subject}
</Text>
<Text
numberOfLines={1}
style={[isRead ? styles.readBody : styles.unReadBody]}
>
{message.body}
</Text>
</View>
<View style={styles.datePart}>
<Text style={{ color: colors.shadow }}>
{dayjs(createdAt).fromNow()}
</Text>
</View>
</View>
</TouchableOpacity>
);
})}
</View>
);
};
Actually behaviour is just rendering white screen with error
Possible Unhandled Promise Rejection (id: 17):
Error: Objects are not valid as a React child (found: object with keys {id, msg_type, created_at, subject, body, author, company_id, read}). If you meant to render a collection of children, use an array instead.

there is problem with your call back function:
you are not returning Messages component
1:Remove curly braces
return (
<FlatList
data={messages}
renderItem={() => <Messages messages={messages}/> }
/>
);
2:Add return statement
return (
<FlatList
data={messages}
renderItem={() => {
return <Messages messages={messages} />;
}}
/>
);

Couple things:
You're using the renderItem callback incorrectly:
<FlatList
data={messages}
renderItem={() => {
// ^ ignoring the renderItem props
return <Messages messages={messages} />;
}}
/>
Here, for each item in the messages array, you're rendering a component and passing all the messages into it. So you'll get repeated elements.
The renderItem callback is passed {item, index} where item is the CURRENT item in the array (index is the index into the array)
See docs here:
https://reactnative.dev/docs/flatlist
The usual thing is the renderItem callback renders ONE item at a time, like this:
<FlatList
data={messages}
renderItem={({item}) => {
return <Message message={item} />;
}}
/>
e.g. I'd make a <Message/> component that renders one item only.

Related

How to pass onPress to props.children?

I'm trying to make a wrapper component in react-native that I can pass down all its props to the children it wraps around. What I really want is to pass down all function props down to all its children. It looks something like this below. I want the onPress in Wrapper to be called when the TouchableOpacity is pressed.
I tried this below but it doesn't work
const Wrapper = ({children,...props})=>{
return <View {...props}>{children}</View>
}
const App = ()=>{
return (
<View style={{flex:1}}>
<Wrapper onPress={()=>{console.log(2)}}>
<TouchableOpacity/>
</Wrapper>
</View>
)
}
It looks like you're looking to map the children and apply the props to each one. That might look like this:
const Wrapper = ({children,...props})=>{
return (<>
{React.Children.map(children, child => (
React.cloneElement(child, {...props})
))}
</>);
}
(method of mapping the children borrowed from this answer)
const App = () => {
return (
<View style={{ flex: 1 }}>
<TouchableOpacity onPress={() => {
// do the action need here here
}}>
<Wrapper >
</Wrapper>
</TouchableOpacity>
</View>
)
}
I would advise you to use hooks function instead
If you try to reuse functions that are related
** useAdd.js **
export default () => {
const addFuction(a, b) => {
// do preprocessing here
return a + b
}
return [addFuction]
}
main componet
import useAdd from "/useAdd";
const App = () => {
const [addFuction] = useAdd()
return (
<View style={{ flex: 1 }}>
<TouchableOpacity onPress={() => {
addFuction(4,5)
}}>
...action component...
</TouchableOpacity>
</View>
)
}
console in useAdd hook.... to see visual changes use the react useState

How do I change the state present in a specific item within a flatlist?

I am generating a flatlist that contains comments. Inside the comment component, I'm using a state isCollpsed to determine if the individual comment is collapsed or not. Pressing on each individual comment does make it collapse. However, I want to manipulate this state from the parent component without affecting every other comment. How could I achieve this?
I tried using the reference hook to access each individual item in the flatlist but it keeps returning 'undefined'. I'm using the react-native-collapsible library to collapse the comments.
My Flatlist:
<FlatList
data={SAMPLE_COMMENTS}
keyExtractor={keyExtractor}
renderItem={({item})=>
<Comment
ref={(el) => {rowRefs.current[item.id] = el} }
onPress={()=>{rowRefs.current[item.id].collapseFunction()}}
body={item.body}
author={item.author}
level={item.level}
createdAt={item.createdAt}
commentId={item.id}
commentChildren={item.replies} />}
/>
Comment Component :
const [isCollapsed, setIsCollapsed] = useState(false);
const collapseFunction = () => {setIsCollapsed(!isCollapsed)};
return (
<Collapsible collapsed={isCollapsed}>
<TouchableWithoutFeedback onPress={onPress}>
<View style={styles.container}>
</View>
</TouchableWithoutFeedback>
</Collapsible>
you can use recursive function
// add this to parent
<MapComments
comments={SAMPLE_COMMENTS}
childClickHandler={onItemClickHandler}
/>
// MapComments component
const MapComments= ({
Comments= [],
childClickHandler,
}) => {
return (
<ScrollView>
<Tree
CommentTree={CommentTree}
childClickHandler={childClickHandler}
/>
</ScrollView>
);
};
const Tree = ({CommentTree= [], childClickHandler}) => {
return (
<View>
{CommentTree.map(tree => (
<TreeNode
key={tree.commentId}
node={tree}
childClickHandler={childClickHandler}
/>
))}
</View>
);
};
const TreeNode = ({node, childClickHandler}) => {
const [childVisible, setChildVisiblity] = useState(false);
const hasChild = node.commentChildren.length > 0 ? true : false;
return (
<View
style={{marginRight: node.Level > 1 ? 40 : null}}>
<TouchableOpacity
onPress={() =>
hasChild ? setChildVisiblity(prev => !prev) : childClickHandler(node)
}>
<Text numberOfLines={1} style={styles.label}>
{node.body}
</Text>
{hasChild ? (
<AntDesign name={childVisible ? 'minus' : 'plus'}
/>
) : (
<FontAwesome name="circle" />
)}
</TouchableOpacity>
{hasChild && childVisible && (
<Tree
childClickHandler={childClickHandler}
knowledgeTree={node.commentChildren}
/>
)}
</View>
);
};

Property not being added to object

I have a object which has an array inside it. Each array has multiple objects. So using the .map function I am looping over the array inside the object. Each array item has a click function where I toggle the item. Initial state of the array item is this
{
DisplayText: "Foresatte"
Selectable: true
UserRecipientToInclude: "IncludeGuardianRecipient"
}
When I do this
choice.Selected = false
and console logs the result the newly added item is not present in the object. Why is that?
Here is the code
{c.UserDropdownMenuChoices.map(choice => {
return ( <TouchableHighlight
{...testProperties(choice.DisplayText, true)}
style={{ opacity: !choice.Selectable ? 0.4 : 1 }}
onPress={() => {
this.selectChoice(c.UserDropdownMenuChoices, choice, c)
}}
underlayColor={'transparent'}
key={choice.DisplayText}
>
<View style={styles.choiceContainer}>
{
choice.selected ? (
//<MaterialCommunityIcons name={'checkbox-marked'} style={styles.checkboxClick} size={20} />
<Icon
type={'material-community'}
name={'checkbox-marked'}
iconStyle={styles.checkboxClick}
size={20}
/>
) : (
<Icon
type={'material-community'}
name={'checkbox-blank-outline'}
iconStyle={styles.checkboxDefault}
size={20}
/>
)
//DONE: <MaterialCommunityIcons name={'checkbox-blank-outline'} style={styles.checkboxDefault} size={20} />
}
<Text style={styles.displayText}>{choice.DisplayText}</Text>
</View>
</TouchableHighlight> )}
and my function is like this
selectChoice(choicesList, choice, contact) {
choice.selected = true
...
console.log(choice) // doesn't have the new property
}
This code is for a react native application
I have previously solved a similar issue by simply scoping out the select hook inside the .map without mapping the attribute onto the array itself.
So what I did was:
import MenuRow from "./menu_row"
...
const Rooms = allRooms.map((room, index) => {
return (
<MenuRow key={room.id} room={room}/>
)
})
Inside MenuRow.js
const MenuRow = (props) => {
let room = props.room
const [selected, setSelected] = useState(true) // Checked by default
return (
<TouchableOpacity onPress={() => {setSelected(!selected), applySelected(room.id, selected) }} style={s.checkrow}>
...
{selected ?
// SELECTED
<View style={s.checked}></View>
:
// NOT SELECTED
<View style={s.unchecked}></View>
}
</TouchableOpacity>
)
However you could also give this a try:
https://stackoverflow.com/a/44407980/4451733

Invalid Hook Call - React Hooks

I'm really new to JS and React. I get this error:
Invalid Hook Call
when I try to make a component appear and disappear when another component is clicked. This is my code:
const RenderList = ({data}) => {
return data.map((option, index) => {
return <Item title={option}/>
});
};
const Header = ({ title, style, press }) => (
<TouchableHighlight onPress={press}>
<Text style={style} >{title}</Text>
</TouchableHighlight>
)
const RenderItem = ( {item} ) => {
console.log(styles)
let dataToShow;
const [listState, setListState] = useState(true);
if (listState){
dataToShow = <RenderList data={item.data}/>
} else {
dataToShow = <Text/>
}
return (
<View style={styles.section}>
<Header title={item.title} style={styles.header} press={setListState(!listState)}/>
{dataToShow}
</View>
)}
EDIT
RenderItem is used in a flat list element as a function. (From what I understand)
const SettingsSection = (props) => {
const db = props.data;
return(
<View>
<FlatList
style={styles.sectionList}
data={db}
renderItem={RenderItem}
keyExtractor={item=>item.title}
ItemSeparatorComponent={FlatListItemSeparator}
/>
</View>
);
}
renderItem, as the name suggests, is a render prop, and as such is called directly (like so: renderItem({item})), not instantiated as a component (like so: <RenderItem item={item}/>).
This translates to React not creating the appropriate rendering "context" for hooks to work. You can make sure your RenderItem function is instantiated as a component by using it like this on the render prop:
<FlatList
style={styles.sectionList}
data={db}
renderItem={item => <RenderItem {...item}/>} // see here!
keyExtractor={item=>item.title}
ItemSeparatorComponent={FlatListItemSeparator}
/>
That way, RenderItem is treated as a component and thus can use hooks.
I think problem is occurring due to setListState(!listState) with press. I suggest you to wrap your state changing method into a function. Because onPress accepts only function type but you are giving it a return statement from hooks.
const RenderList = ({data}) => {
return data.map((option, index) => {
return <Item title={option}/>
});
};
const Header = ({ title, style, press }) => (
<TouchableHighlight onPress={press}>
<Text style={style} >{title}</Text>
</TouchableHighlight>
)
const RenderItem = ( {item} ) => {
console.log(styles)
let dataToShow;
const [listState, setListState] = useState(true);
if (listState){
dataToShow = <RenderList data={item.data}/>
} else {
dataToShow = <Text/>
}
return (
<View style={styles.section}>
<Header
title={item.title}
style={styles.header}
press={()=>{
setListState(!listState)
}}
/>
{dataToShow}
</View>
)}

Show Empty list message only after Loader get ended in React Native using Flat list

I have a flat list, which gets its data source as a state. Actually, this data is from firebase, and i have been using redux. So, the data is fetched in the actions, and using callback i get the data to state.
What i want to achieve is, when there is no data found from the api, An empty list message should be show in the view. Actually , i achieved this using "ListEmptyComponent". But whats happening is the screen starts with empty message, and the spinner loads below it, and then if data found the message goes away as well as spinner.
But, what i wanted is, when the view gets rendered the first thing everyone should see is the spinner, and then if data empty spinner hides then empty list message displays.
How to achieve this ?
My Action :
export const fetchOrderHistory = (phone, callback) => {
return (dispatch) => {
dispatch({ type: START_SPINNER_ACTION_FOR_ORDER_HISTORY })
firebase.database().ref('orders/'+phone)
.on('value', snapshot => {
const snapShotValue = snapshot.val();
callback(snapShotValue);
dispatch ({ type: ORDER_HISTORY_FETCHED , payload: snapshot.val()});
dispatch({ type: STOP_SPINNER_ACTION_FRO_ORDER_HISTORY })
});
};
};
My Flat List & spinner:
<FlatList
data={this.state.historyOfOrders}
keyExtractor={item => item.uid}
ListEmptyComponent={this.onListEmpty()}
renderItem={({ item }) => (
<Card
containerStyle={{ borderRadius: 5 }}
>
<View style={styles.topContainerStyle}>
<View>
<TouchableOpacity
onPress={() => this.props.navigation.navigate('ViewOrderScreen', {itemsOfOrder: item}) }
>
<View style={styles.viewOrderContainer}>
<View style={styles.viewOrderTextContainer}>
<Text style={styles.viewOrderTextStyle}>View Order</Text>
</View>
<Icon
name='ios-arrow-forward'
type='ionicon'
color='#ff7675'
/>
</View>
</TouchableOpacity>
</View>
</View>
</View>
</Card>
)}
/>
{this.props.isSpinnerLoading &&
<View style={styles.loading}>
<ActivityIndicator size="large" color="#03A9F4"/>
</View> }
My Call back at componentWillMount which set state:
componentWillMount() {
this.props.fetchOrderHistory((this.props.phone), (snapShotValue)=> {
const userOrderHistory = _.map(snapShotValue, (val,uid) => ({uid, ...val}))
this.setState({ historyOfOrders: userOrderHistory })
});
}
My EmptyList Message:
onListEmpty = () => {
return <View style={{ alignSelf: 'center' }}>
<Text style={{ fontWeight: 'bold', fontSize: 25 }}>No Data</Text>
</View>
}
My State:
state = { historyOfOrders: "" }
I am getting the spinner values from the reducers, using mapStateToProps.
Kindly Guide me, through
you have to do two things for that.
First, show Flatlist only if the loader is stopped. Second, set default value of this.state.historyOfOrders is null and check if this.state.historyOfOrders not null then only show Flatlist.
Here is a code:
{(!this.props.isSpinnerLoading && this.state.historyOfOrders != null) ?
(
<FlatList
data={this.state.historyOfOrders}
keyExtractor={item => item.uid}
ListEmptyComponent={this.onListEmpty()}
renderItem={({ item }) => (
<Card containerStyle={{ borderRadius: 5 }}>
<View style={styles.topContainerStyle}>
<View>
<TouchableOpacity onPress={() => this.props.navigation.navigate('ViewOrderScreen', {itemsOfOrder: item}) }>
<View style={styles.viewOrderContainer}>
<View style={styles.viewOrderTextContainer}>
<Text style={styles.viewOrderTextStyle}>View Order</Text>
</View>
<Icon
name='ios-arrow-forward'
type='ionicon'
color='#ff7675'
/>
</View>
</TouchableOpacity>
</View>
</View>
</Card>
)}
/>
) : null
}
With this condition, even if you want loader above Flatlist you can do that.
The path you should take is rendering only the spinner when the loading flag is set and rendering the list when loading flag is false.
Your render method should be like below
render()
{
if(this.props.isSpinnerLoading)
{
return (<View style={styles.loading}>
<ActivityIndicator size="large" color="#03A9F4"/>
</View> );
}
return (/** Actual List code here **/);
}

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