I want to store an array state using async storage. but everytime i reload the app, it comes up blank. below is a sample code, and I have shown only the functions for better clarity.
componentDidMount() {
this.getDataSync();
}
getDataSync = async () => {
try {
const list = await AsyncStorage.getItem(LIST_STORAGE_KEY);
const parsedList = JSON.parse(list);
const obj = Object.keys(parsedList);
this.setState({ isDataReady: true, list: obj || [] });
} catch (e) {
Alert.alert('Failed to load list.');
}
}
handleAdd() {
const { firstname, lastname, email, phone} = this.state;
const ID = uuid();
const newItemObject = {
key: ID,
firstname: firstname,
lastname: lastname,
email: email,
phone: phone,
image: null,
};
this.setState(prevState => ({
list: [...prevState.list, newItemObject]
}));
this.saveItems(this.state.list);
}
saveItems = list => {
AsyncStorage.setItem(LIST_STORAGE_KEY, JSON.stringify(list));
};
You are not saving your list but getting keys from the list. const obj = Object.keys(parsedList); you are saving array indexes to state.
getDataSync = async () => {
try {
const list = await AsyncStorage.getItem(LIST_STORAGE_KEY);
const parsedList = JSON.parse(list);
this.setState({
isDataReady: true,
list: Array.isArray(parsedList) && parsedList.length && parsedList || []
});
} catch (e) {
Alert.alert('Failed to load list.');
}
}
Also pass saveItems as a callback to save the correct data.
this.setState(prevState => ({
list: [...prevState.list, newItemObject]
}), () => this.saveItems(this.state.list));
The .setState() method is may be asynchronous, so the result of setting the state, cannot be used immediately after setting it. If you want to use the results of setting the state, you should use the callback (2nd param), which is called after the state is actually set:
this.setState(
prevState => ({
list: [...prevState.list, newItemObject]
}),
() => this.saveItems(this.state.list)
);
Related
I'm trying to filter a players array by comparing the names property to a roster array and rendering the matches from the players array.
When a user selects a year the getCollegeRoster() function returns players who have a year property matching the selection. From there I'm trying to filter and display the .name matches from the players array, but it seems i'm unable to update playerStateValue. I'm using recoil to manage state. Any insight would be much appreciated.
const getCollegeRoster = async () => {
setLoading(true);
try {
const playersQuery = query(
collection(firestore, `colleges/${communityData.id}/rosters`),
where("year", "==", selection),
);
const playerDocs = await getDocs(playersQuery);
const collegeRoster = playerDocs.docs.map((doc) => ({ id: doc.id, ...doc.data() }));
setRoster(collegeRoster as unknown as Roster[]);
console.log('collegePlayers', roster);
} catch (error: any) {
console.log("getCollegePlayers error", error.message);
}
setLoading(false);
};
const onSelection = (newSelection: any) => {
setSelection(newSelection);
console.log('newselect', newSelection)
getCollegeRoster();
const filteredArray = [...playerStateValue.players].filter((el) => ({
name: el.name,
match: [...roster].some((f) => f.name === el.name)
})
);
setPlayerStateValue((prev) => ({
...prev,
players: filteredArray as Player[],
playersCache: {
...prev.playersCache,
[communityData?.id!]: filteredArray as Player[],
},
playerUpdateRequired: false,
}));
} ```
also tried adding setplayerstatevalue into the getcollegeroster function:
onst getCollegeRoster = async () => {
console.log("WE ARE GETTING Players!!!");
console.log('communitydata', communityData);
setLoading(true);
try {
const playersQuery = query(
collection(firestore, `colleges/${communityData.id}/rosters`),
where("year", "==", selection),
);
const playerDocs = await getDocs(playersQuery);
const collegeRoster = playerDocs.docs.map((doc) => ({ id: doc.id, ...doc.data() }));
setRoster(collegeRoster as unknown as Roster[]);
console.log('collegePlayers', roster);
const filteredArray = [...playerStateValue.players].filter((el) => ({
name: el.name,
match: [...roster].some((f) => f.name === el.name)
})
);
setPlayerStateValue((prev) => ({
...prev,
players: filteredArray as Player[],
playersCache: {
...prev.playersCache,
[communityData?.id!]: filteredArray as Player[],
},
playerUpdateRequired: false,
}));
} catch (error: any) {
console.log("getCollegePlayers error", error.message);
}
setLoading(false);
};
{playerStateValue.players.map((player: Player, index) => (
<PlayerItem
key={player.id}
player={player}
// postIdx={index}
onPlayerVote={onPlayerVote}
userVoteValue={
playerStateValue.playerVotes.find((item) => item.playerId === player.id)
?.voteValue
}
onSelectPlayer={onSelectPlayer}
/>
I believe I found the problem. getCollegeRoster() is an async function which means it is being executed asynchronous.
That function is responsible for updating roster and you are using roster inside your filtering while it is being asynchronously updated.
There is no guarantee that roster is updated by the time you filter your array.
You have two ways of solving this. Either you execute setPlayerStateValue() inside of getCollegeRoster() or you wait for getCollegeRoster() to be done by preappending it with await and your onSelection function with async:
const onSelection = async (newSelection: any) => {
setSelection(newSelection);
console.log("newselect", newSelection);
await getCollegeRoster();
const filteredArray = [...playerStateValue.players].filter((el) => ({
name: el.name,
match: [...roster].some((f) => f.name === el.name),
}));
...
Edit:
Another scenario I can think of is that playerStateValue might be the culprit. In React setState works asynchronous as well, if you access playerStateValue via curr/prev-callback, it is guaranteed that you are accessing the values of the current state object while updating the state. Try this use of setPlayerStateValue:
setPlayerStateValue((prev) => {
const filteredArray = prev.players.filter((el) => ({
name: el.name,
match: [...roster].some((f) => f.name === el.name),
})) as Player[];
return {
...prev,
players: filteredArray,
playersCache: {
...prev.playersCache,
[communityData?.id!]: filteredArray,
},
playerUpdateRequired: false,
};
});
I'm trying to make a list in my react app. I have retrieved data from my database, and pushed it into a list. I have doublechecked that the data shows up correctly in the console, and it does, but array.map() returns nothing. I think the problem might be that array.map() runs two times. I don't know why it runs two times.
function Dashboard() {
const user = firebase.auth().currentUser;
const [teams, setTeams] = useState([])
const history = useHistory();
useEffect(() => {
getTeams()
if (user) {
} else {
history.push("/")
}
}, [])
function Welcome() {
if (user) {
return <h1>Welcome, {user.displayName}</h1>
} else {
}
}
const getTeams = () => {
firebase.firestore().collectionGroup('members').where('user', '==', user.uid).get().then((snapshot) => {
const docList = []
snapshot.forEach((doc) => {
docList.push({
teamId: doc.data().teamId,
})
})
const teamslist = []
docList.forEach((data) => {
firebase.firestore().collection('teams').doc(data.teamId).get().then((doc) => {
teamslist.push({
name: doc.data().name,
teamId: doc.id,
})
})
})
setTeams(teamslist)
})
}
const openTeam = (data) => {
console.log(data.teamId)
}
return (
<div>
<Welcome />
<div>
<ul>
{console.log(teams)}
{teams.map((data) => {
return (
<li onClick={() => openTeam(data)} key={data.teamId}>
<h1>{data.name}</h1>
<p>{data.teamId}</p>
</li>
)
})}
</ul>
</div>
</div>
)
}
export default Dashboard
The getTeams function has a bug where it isn't waiting for the firebase.firestore().collection('teams').doc(data.teamId).get().then promises to finish before calling setTeams, so it is called with an empty array, causing React to trigger a render with the empty array.
As the promises for fetching each team resolve they will be pushed to the same array reference, but this won't trigger a rerender in React since you're not calling setTeams again when the array changes.
Try this code, which won't call setTeams until each team promise generated from docList has been resolved.
const getTeams = () => {
firebase.firestore().collectionGroup('members').where('user', '==', user.uid).get().then((snapshot) => {
const docList = []
snapshot.forEach((doc) => {
docList.push({
teamId: doc.data().teamId,
})
})
const teamslist = [];
Promise.all(docList.map((data) => {
return firebase
.firestore()
.collection('teams')
.doc(data.teamId)
.get()
.then((doc) => {
teamslist.push({
name: doc.data().name,
teamId: doc.id,
})
})
}))
.then(() => setTeams(teamslist));
})
}
A smaller edit would be to call setTeams after each separate team promise resolves, which will trigger a React render each time a new team is resolved:
.then((doc) => {
teamslist.push({
name: doc.data().name,
teamId: doc.id,
});
// create a new array, since using the same array
// reference won't cause react to rerender
setTeams([...teamslist]);
})
Many thanks to #martinstark who provided you an answer while I was unavailable.
However, there are some more things that need to be covered.
User State
In your current component, you pull the current user from Firebase Authentication, but don't handle the state changes of that user - signing in, signing out, switching user. If a user is signed in and they were to navigate directly to your dashboard, firebase.auth().currentUser could be momentarily null while it resolves the user's login state, which would incorrectly send them off to your login page.
This can be added using:
const [user, setUser] = useState(() => firebase.auth().currentUser || undefined);
const userLoading = user === undefined;
useEffect(() => firebase.auth().onAuthStateChanged(setUser), []);
Next, in your first useEffect call, you call getTeams() whether the user is signed in or not - but it should depend on the current user.
useEffect(() => {
if (userLoading) {
return; // do nothing (yet)
} else if (user === null) {
history.push("/");
return;
}
getTeams()
.catch(setError);
}, [user]);
// This getTeams() is a () => Promise<void>
const getTeams = async () => {
const membersQuerySnapshot = await firebase.firestore()
.collectionGroup('members')
.where('user', '==', user.uid)
.get();
const docList = []
membersQuerySnapshot.forEach((doc) => {
docList.push({
teamId: doc.get("teamId"), // better perfomance than `doc.data().teamId`
});
});
const teamDataList = [];
await Promise.all(docList.map((data) => {
return firebase.firestore()
.collection('teams')
.doc(data.teamId)
.get()
.then(doc => teamDataList.push({
name: doc.get("name"),
teamId: doc.id
}));
}));
setTeams(teamDataList);
}
Optimizing getTeams() - Network Calls
The getTeams function in your question calls setTeams with the array [], which will be empty at the time of calling it as covered in #martinstark's answer. The "get team data" operations are asyncronous and you aren't waiting for them to resolve before updating your state and triggering a new render. While you are pushing data to them after the component has rendered, modifying the array won't trigger a new render.
While you could fetch the data for each team using db.collection("teams").doc(teamId).get(), each of these is requests is a network call, and you can only make a limited number of these in parallel. So instead of fetching 1 team per network call, you could fetch up to 10 teams per network call instead using the in operator and FieldPath.documentId().
Assuming the collectionGroup("members") targets the collections of documents at /teams/{aTeamId}/members which contain (at least):
"/teams/{aTeamId}/members/{memberUserId}": {
teamId: aTeamId,
user: memberUserId, // if storing an ID here, call it "uid" or "userId" instead
/* ... */
}
// this utility function lives outside of your component near the top/bottom of the file
function chunkArr(arr, n) {
if (n <= 0) throw new Error("n must be greater than 0");
return Array
.from({length: Math.ceil(arr.length/n)})
.map((_, i) => arr.slice(n*i, n*(i+1)))
}
// This getTeams() is a () => Promise<void>
const getTeams = async () => {
const membersQuerySnapshot = await firebase.firestore()
.collectionGroup('members')
.where('user', '==', user.uid)
.get();
const teamIDList = []
membersQuerySnapshot.forEach((doc) => {
teamIDList.push(doc.get("teamId")); // better perfomance than `doc.data().teamId`
})
const chunkedTeamIDList = chunkArr(teamIDList, 10) // split into batches of 10
const teamsColRef = firebase.firestore().collection('teams');
const documentId = firebase.firestore.FieldPath.documentId(); // used with where() to target the document's ID
const foundTeamDocList = await Promise
.all(chunkedTeamIDList.map((chunkOfTeamIDs) => {
// fetch each batch of IDs
return teamsColRef
.where(documentId, 'in', chunkOfTeamIDs)
.get();
}))
.then((arrayOfQuerySnapshots) => {
// flatten results into a single array
const allDocsList = [];
arrayOfQuerySnapshots.forEach(qs => allDocsList.push(...qs.docs));
return allDocsList;
});
const teamDataList = foundTeamDocList
.map((doc) => ({ name: doc.get("name"), teamId: doc.id }));
// sort by name, then by ID
teamDataList.sort((aTeam, bTeam) =>
aTeam.name.localeCompare(bTeam.name) || aTeam.teamId.localeCompare(bTeam.teamId)
)
// update state & trigger render
setTeams(teamDataList);
}
You can also make use of this utility function to simplify & optimize the code a bit. Which gives:
// This getTeams() is a () => Promise<void>
const getTeams = async () => {
const membersQuerySnapshot = await firebase.firestore()
.collectionGroup('members')
.where('user', '==', user.uid)
.get();
const teamIDList = []
membersQuerySnapshot.forEach((doc) => {
teamIDList.push(doc.get("teamId")); // better perfomance than `doc.data().teamId`
})
const teamsColRef = firebase.firestore().collection('teams');
const teamDataList = [];
await fetchDocumentsWithId(
teamsColRef,
teamIDList,
(doc) => teamDataList.push({ name: doc.get("name"), teamId: doc.id })
);
// sort by name, then by ID
teamDataList.sort((aTeam, bTeam) =>
aTeam.name.localeCompare(bTeam.name) || aTeam.teamId.localeCompare(bTeam.teamId)
)
// update state & trigger render
setTeams(teamDataList);
}
Optimizing getTeams() - Function Definition
As part of the last optimization, you could pull it out of your component or place it in its own file so that it's not redefined with every render:
// define at top/bottom of the file outside your component
// This getTeams() is a (userId: string) => Promise<{ name: string, teamId: string}[]>
async function getTeams(userId) => {
const membersQuerySnapshot = await firebase.firestore()
.collectionGroup('members')
.where('user', '==', userId)
.get();
const teamIDList = []
membersQuerySnapshot.forEach((doc) => {
teamIDList.push(doc.get("teamId")); // better perfomance than `doc.data().teamId`
})
const teamsColRef = firebase.firestore().collection('teams');
const teamDataList = [];
await fetchDocumentsWithId(
teamsColRef,
teamIDList,
(doc) => teamDataList.push({ name: doc.get("name"), teamId: doc.id })
);
// sort by name, then by ID
teamDataList.sort((aTeam, bTeam) =>
aTeam.name.localeCompare(bTeam.name) || aTeam.teamId.localeCompare(bTeam.teamId)
)
// return the sorted teams
return teamDataList
}
and update how you use it:
useEffect(() => {
if (userLoading) {
return; // do nothing
} else if (user === null) {
history.push("/");
return;
}
getTeams(user.uid)
.then(setTeams)
.catch(setError);
}, [user]);
I have API query and getting the result and setting those in a state variable in Oncompleted method of API query, Now i am updating the same state variable in another api query "onCompleted method.
I am not able to access the result from state what i have set before in first api query and below is my code
Query 1:
const designHubQueryOnCompleted = designHubProject => {
if (designHubProject) {
const {
name,
spaceTypes
} = designHubProject;
updateState(draft => { // setting state here
draft.projectName = name;
draft.spaceTypes = (spaceTypes || []).map(po => {
const obj = getTargetObject(po);
return {
id: po.id,
name: obj.name,
category: obj.librarySpaceTypeCategory?.name,
description: obj.description,
warning: null // trying to modify this variable result in another query
};
});
});
}
};
const { projectDataLoading, projectDataError } = useProjectDataQuery(
projectNumber,
DESIGNHUB_PROJECT_SPACE_TYPES_MIN,
({ designHubProjects }) => designHubQueryOnCompleted(designHubProjects[0])
);
Query 2:
const {
// data: designhubProjectSpaceTypeWarnings,
loading: designhubProjectSpaceTypeWarningsLoading,
error: designhubProjectSpaceTypeWarningsError
} = useQuery(DESIGNHUB_PROJECT_LINKED_SPACETYPE_WARNINGS, {
variables: {
where: {
projectNumber: { eq: projectNumber }
}
},
onCompleted: data => {
const projectSpaceTypeWarnings = data.designHubProjectLinkedSpaceTypeWarnings[0];
const warnings = projectSpaceTypeWarnings.spaceTypeWarnings.reduce((acc, item) => {
const spaceTypeIdWithWarningState = {
spaceTypeId: item.spaceTypeProjectObjectId,
isInWarningState: item.isInWarningState
};
acc.push(spaceTypeIdWithWarningState);
return acc;
}, []);
console.log(state.spaceTypes); // trying to access the state here but getting empty array
if (state.spaceTypes.length > 0) {
const updatedSpaceTypes = state.spaceTypes;
updatedSpaceTypes.forEach(item => {
const spaceTypeWarning = { ...item };
spaceTypeWarning.warning = warnings?.filter(
w => w.spaceTypeId === spaceTypeWarning.id
).isInWarningState;
return spaceTypeWarning;
});
updateState(draft => {
draft.spaceTypes = updatedSpaceTypes;
});
}
}
});
Could any one please let me know where I am doing wrong with above code Or any other approach to modify the state, Many thanks in advance!!
I am trying to add and delete an obect from an array, I have been able to figure out the add object part, but the deletion is not working. I have used filter() but it did nothing. Now I am using splice, it works but it deletes the first element, instead of the selected item. below is a sample code, and I have shown only the functions for better clarity.
handleDelete(item) {
this.setState(({ list}) => {
const newList = [...list];
newList.splice(item.key, 1);
console.log('deleted', newList);
return { list: newList };
});
}
handleAdd() {
const { firstname, lastname, email, phone} = this.state;
const ID = uuid();
const newItemObject = {
key: ID,
firstname: firstname,
lastname: lastname,
email: email,
phone: phone,
image: null,
};
this.setState(prevState => ({
list: [...prevState.list, newItemObject]
}));
}
I would like to
The item's key and index in the array are probably not the same. If the item is in the array, you can use Array.indexOf() to find it's index, and splice it out:
handleDelete(item) {
this.setState(({ list }) => {
const newList = [...list];
const index = newList.indexOf(item);
newList.splice(index, 1);
return {
list: newList
};
});
}
Or if you want to use Array.filter(), check if the key of of current element (o) is different from that of item:
handleDelete(item) {
this.setState(({ list }) => ({
list: list.filter(o => o.key !== item.key)
}))
}
I can retrieve data from a Firebase database, but when I try to assign the fetched data from the database, the object properties require you to invoke a getter (I mean I can't access them after assignment)
This is the Vue instance.
Yes, I know. This is formatted weirdly, this is something that VS Code does for me...
export default {
name: "Home",
data() {
return {
users: []
};
},
created() {
db.collection("users")
.get()
.then(snapshot => {
snapshot.forEach(doc => {
let user = doc.data();
user.id = doc.id;
this.users.push(user);
console.log(this.users);
});
});
}
};
When I open up the console I need to click on three dots to get the actual data.
The following should do the trick:
export default {
name: "Home",
data() {
return {
users: []
};
},
created() {
db.collection("users")
.get()
.then(snapshot => {
let usersArray = [];
snapshot.forEach(doc => {
let user = doc.data();
user.id = doc.id;
usersArray.push(user);
});
this.users = usersArray;
console.log(this.users);
});
}
};