英文:
fetch() in js (react hooks) - can I access data in third then?
问题
I'm practicing react and fetch api and I want to send some data but it does not work... Code:
fetch('http://localhost:3003/users', {method: 'POST',body: JSON.stringify({ name, password }),headers: {'Content-Type': 'application/json'}}).then(res => {if (res.ok) {return res.json();}throw new Error('Error');}).then(user => {setUser([...users, user]);console.log(user.id);setLoggedUserID(user.id);}).then(setLoggedUserID(13)) // Check added user's ID.then(errorUserChange(false)); // Change state and go to /loggedin page
In second then I receive user with name, password and id. When I console.log it, I can see proper id, but when I'm trying to send it with setLoggedUserID function to the state, I receive null. This function works fine in the next then (third), but over there I don't have access to data (above I've hardcoded 13). Whole fetch is in function called after form submission.
Any ideas? Thanks!
英文:
I'm practicing react and fetch api and I want to send some data but it does not work... Code:
fetch('http://localhost:3003/users', {method: 'POST',body: JSON.stringify({ name, password }),headers: {'Content-Type': 'application/json'}}).then(res => {if (res.ok) {return res.json();}throw new Error('Error');}).then(user => {setUser([...users, user]);console.log(user.id);setLoggedUserID(user.id);}).then(setLoggedUserID(13)) // Check added user's ID.then(errorUserChange(false)); // Change state and go to /loggedin page
In second then I receive user with name, password and id. When I console.log it, I can see proper id, but when I'm trying to send it with setLoggedUserID function to the state, I receive null. This function works fine in the next then (third), but over there I don't have access to data (above I've hardcoded 13). Whole fetch is in function called after form submission.
Any ideas? Thanks!
答案1
得分: 1
你需要将一个函数传递给then()。
你试图调用setLoggedUserID(13)并将其返回值作为回调函数传递。
英文:
You need to pass a function to then().
You are trying to call setLoggedUserID(13) and pass its return value as the callback function.
答案2
得分: 1
const res = await fetch('http://localhost:3003/users', {
method: 'POST',
body: JSON.stringify({ name, password }),
headers: {
'Content-Type': 'application/json'
}
});
const user = await res.json();
setUser(prev => [...prev, user]);
setLoggedUserID(user.id); // [loggedUserId, setLoggedUserID] = useState(null)
//
useEffect(() => {
if (loggedUserId) errorUserChange(false);
}, [loggedUserId]);
英文:
const res = await fetch('http://localhost:3003/users', {method: 'POST',body: JSON.stringify({ name, password }),headers: {'Content-Type': 'application/json'}});const user = await res.json();setUser(prev => [...prev, user]);setLoggedUserID(user.id); // [loggedUserId, setLoggedUserID] = useState(null)
//
useEffect(() => {if (loggedUserId) errorUserChange(false);}, [loggedUserId]);
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