Hej, I advanced my FlatList in React Native with a) inbox/archive views and b) with standard filter functionalities.
It's working somehow, but is not production ready! Can someone please check this (I think well-organized) code and tell me where I do what wrong?
What is not working: a) FlatList does not always re-render/update when the stream state, which is its data prop, changes b) FlatList does not remove an item immediately when I archive/unarchive via swipe functionality. I have to manually change the view to see ... c) FlatList does not directly apply the filter on state, I have to click twice to make it happen ...
//React
import { View, StyleSheet, Pressable, Animated, FlatList } from "react-native";
import { useCallback, useContext, useEffect, useState, useMemo } from "react";
//Internal
import SelectBtn from "./SelectBtn";
import SessionComponent from "./SessionComponent";
import LoadingOverlay from "../notification/LoadingOverlay";
import { SessionsContext } from "../../store/context-reducer/sessionsContext";
//External
import { Ionicons } from "@expo/vector-icons";
import { useNavigation } from "@react-navigation/native";
import { database, auth } from "../../firebase";
import { ref, onValue, remove, update } from "firebase/database";
function SessionStream() {
const navigation = useNavigation();
const sessionsCtx = useContext(SessionsContext);
const currentSessions = sessionsCtx.sessions;
const [isFetching, setIsFetching] = useState(true);
const [stream, setStream] = useState([]);
const [inbox, setInbox] = useState([]);
const [archive, setArchive] = useState([]);
const [filter, setFilter] = useState([]);
const sessionList = ["Sessions", "Archive"];
const sortList = ["ABC", "CBA", "Latest Date", "Earliest Date"];
useEffect(() => {
//Fetches all sessions from the database
async function getSessions() {
setIsFetching(true);
const uid = auth.currentUser.uid;
const sessionsRef = ref(database, "users/" uid "/sessions/");
try {
onValue(sessionsRef, async (snapshot) => {
const response = await snapshot.val();
if (response !== null) {
const responseObj = Object.entries(response);
const sessionsData = responseObj.map((item) => {
return {
id: item[1].id,
title: item[1].title,
laps: item[1].laps,
endTime: item[1].endTime,
note: item[1].note,
identifier: item[1].identifier,
date: item[1].date,
smed: item[1].smed,
externalRatio: item[1].externalRatio,
internalRatio: item[1].internalRatio,
untrackedRatio: item[1].untrackedRatio,
archived: item[1].archived,
};
});
sessionsCtx.setSession(sessionsData);
setIsFetching(false);
} else {
sessionsCtx.setSession([]);
setIsFetching(false);
}
});
} catch (err) {
alert(err.message);
setIsFetching(false);
}
}
getSessions();
}, []);
useEffect(() => {
//Sorts sessions into archived and unarchived
setInbox(
currentSessions.filter((session) => {
return session.archived === false || session.archived === undefined;
})
);
setArchive(
currentSessions.filter((session) => {
return session.archived === true;
})
);
}, [currentSessions, archiveHandler, unArchiveHandler, sessionsCtx, stream]);
if (isFetching) {
setTimeout(() => {
return <LoadingOverlay />;
}, 5000);
}
const onPressHandler = useCallback(
//Callback to open the session
(item) => {
navigation.navigate("Detail", {
sessionID: item.id,
});
},
[onPressHandler]
);
const rightSwipeActions = useCallback(
//Swipe actions for the session list
(item, swipeAnimatedValue) => {
return (
<View
style={{
flexDirection: "row",
width: 168,
height: 132,
}}
>
{item.archived === false ? (
<Pressable
onPress={archiveHandler.bind(this, item)}
style={({ pressed }) => pressed && styles.swipePressed}
>
<View style={styles.archive}>
<Animated.View
style={[
styles.archive,
{
transform: [
{
scale: swipeAnimatedValue.interpolate({
inputRange: [0, 1],
outputRange: [0, 1],
extrapolate: "clamp",
}),
},
],
},
]}
>
<Ionicons
name="ios-archive-outline"
size={24}
color="white"
/>
</Animated.View>
</View>
</Pressable>
) : (
<Pressable
onPress={unArchiveHandler.bind(this, item)}
style={({ pressed }) => pressed && styles.swipePressed}
>
<View style={styles.unArchive}>
<Animated.View
style={[
styles.unArchive,
{
transform: [
{
scale: swipeAnimatedValue.interpolate({
inputRange: [0, 1],
outputRange: [0, 1],
extrapolate: "clamp",
}),
},
],
},
]}
>
<Ionicons
name="md-duplicate-outline"
size={24}
color="white"
/>
</Animated.View>
</View>
</Pressable>
)}
<Pressable
onPress={deleteHandler.bind(this, item)}
style={({ pressed }) => pressed && styles.pressed}
>
<View style={styles.trash}>
<Animated.View
style={[
styles.trash,
{
transform: [
{
scale: swipeAnimatedValue.interpolate({
inputRange: [0, 1],
outputRange: [0, 1],
extrapolate: "clamp",
}),
},
],
},
]}
>
<Ionicons name="trash-outline" size={24} color="white" />
</Animated.View>
</View>
</Pressable>
</View>
);
},
[rightSwipeActions]
);
const deleteHandler = useCallback(
(item) => {
try {
sessionsCtx.deleteSession(item.id); // delete from local context
const uid = auth.currentUser.uid;
const sessionRef = ref(
database,
"users/" uid "/sessions/" item.id
);
remove(sessionRef); // delete from firebase
} catch (error) {
alert(error.message);
}
},
[deleteHandler]
);
const archiveHandler = (item) => {
try {
const id = item.id;
const updatedSession = {
...item, // copy current session
archived: true,
};
const uid = auth.currentUser.uid;
const sessionRef = ref(database, "users/" uid "/sessions/" id);
update(sessionRef, updatedSession);
/* sessionsCtx.updateSession(id, updatedSession); */
//update inbox state
setInbox(
currentSessions.filter((session) => {
const updatedData = session.archived === false;
return updatedData;
})
);
//update archive state
setArchive(
currentSessions.filter((session) => {
const updatedData = session.archived === true;
return updatedData;
})
);
} catch (error) {
alert(error.message);
}
};
const unArchiveHandler = (item) => {
try {
const id = item.id;
const updatedSession = {
...item, // copy current session
archived: false,
};
const uid = auth.currentUser.uid;
const sessionRef = ref(database, "users/" uid "/sessions/" id);
update(sessionRef, updatedSession);
/* sessionsCtx.updateSession(id, updatedSession); */
//update unarchived session list
setArchive((preState) => {
//remove the item from archived list
preState.filter((session) => session.id !== item.id);
return [...preState];
});
} catch (error) {
alert(error.message);
}
};
const selectSessionHandler = useCallback(
(selectedItem) => {
switch (selectedItem) {
case "Sessions":
setStream(inbox);
break;
case "Archive":
setStream(archive);
break;
}
},
[selectSessionHandler, inbox, archive]
);
const selectFilterHandler = (selectedItem) => {
//filter the session list
switch (selectedItem) {
case "ABC":
// Use the Array.sort() method to sort the list alphabetically in ascending order
const sortedList = stream.sort((a, b) => {
return a.title.localeCompare(b.title);
});
setStream((preState) => {
return [...sortedList];
});
break;
case "CBA":
// Use the Array.sort() method to sort the list alphabetically in descending order
const sortedList2 = stream.sort((a, b) => {
return b.title.localeCompare(a.title);
});
setStream((preState) => {
return [...sortedList2];
});
break;
case "Latest Date":
// Use the Array.sort() method to sort the list by date in descending order
const sortedList3 = stream.sort((a, b) => {
return b.date.localeCompare(a.date);
});
setStream((preState) => {
return [...sortedList3];
});
break;
case "Earliest Date":
// Use the Array.sort() method to sort the list by date in ascending order
const sortedList4 = stream.sort((a, b) => {
return a.date.localeCompare(b.date);
});
setStream((preState) => {
return [...sortedList4];
});
break;
}
};
const renderSessionItem = useCallback(({ item }) => {
return (
<Pressable
/* style={({ pressed }) => pressed && styles.pressed} */
onPress={onPressHandler.bind(null, item)}
key={item.id}
>
<SessionComponent
key={item.id}
title={item.title}
identifier={item.identifier}
date={item.date}
rightSwipeActions={rightSwipeActions.bind(null, item)}
smed={item.smed}
endTime={item.endTime}
/>
</Pressable>
);
}, []);
return (
<View style={styles.container}>
<View style={styles.menuRow}>
<SelectBtn
data={sortList}
onSelect={(item) => selectFilterHandler(item)}
/>
<SelectBtn
data={sessionList}
onSelect={(item) => selectSessionHandler(item)}
/>
</View>
<FlatList
data={stream}
renderItem={renderSessionItem}
keyExtractor={(item) => item.id}
extraData={stream}
/>
</View>
);
}
export default SessionStream;
What I already tried: I tried ChatGPT the whole day yesterday ... ;-) I tried updating the global state for sessions to trigger re-renders ... I tried updating the local state as obj or via the spread operator to ... I tried extraData prop at FlatList I removed useCallback to make sure it doesnt somehow block ...
CodePudding user response：
can you do this when you are updating your stream state
const oldStream = stream;
const newStream = newStream; // put the value that you have updated
const returnedTarget= Object.assign(stream, newStream);
setStream(returnedTarget);
The problem might be you are mutating the copy obj ref: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/assign
CodePudding user response：
c) in your selectFilterHandler method you are updating filter and in the same method you are trying to use updated filter value. which is not possible as useState does not update value immediately.
b) in your archiveHandler i think you are not updating the setStream state. if you are trying to run
const selectSessionHandler = useCallback(
(selectedItem) => {
switch (selectedItem) {
case "Sessions":
setStream(inbox);
break;
case "Archive":
setStream(archive);
break;
}
},
[selectSessionHandler, inbox, archive]
);
this method whenever inbox/archive changes it will not work it will be work only when you call this method and any of the value in dependency array has changed. (you can use useEffect and pass and deps arr [inbox,archive] which will run every time and can update your state.