I'm trying to figure out why I'm not able to retrieve data from the postgres database.
It works when I use async await, but when I try to to use Promise with .then(result).catch(error), it's not working.
Console log gives me Promise { <pending> }
getUsers
your text`const db = require("../config/db");
const getUsers = () => {
const query = "SELECT * FROM users";
const users = db
.query(query)
.then((result) => {
return result.rows;
})
.catch((error) => {
return error.message;
});
return users;
};
module.exports = {
getUsers,
};
index.js (Using Promise) -- Doesn't work.
const { getUsers } = require('../helpers/users')
export default function Home(props) {
return (
<ul>
{props.name}
{props.users.map(user => (
<li key={user.id}>{user.name}</li>
))}
</ul>
)
}
export function getServerSideProps(context) {
const users = getUsers()
.then((result) => {
return result.rows;
})
.catch((error) => {
return error.message;
})
return {
props: {
users
}
}
}
index.js (Using Async/Await) -- Works.
export async function getServerSideProps(context) {
const users = await getUsers()
return {
props: {
users
}
}
}
That should work (according the Next doc getServerSideProps is async function). So just add async keyword and return promise from that function:
export async function getServerSideProps(context) {
return getUsers()
.then((result) => {
return {props:{user:result.rows}};
})
.catch((error) => {
return {props:{user:error.message}};
})
}
Thank you Andrey and Bergi.
Since it's Promise, I did not have to include the async, but the rest of the code did indeed work!
export function getServerSideProps(context) {
getUsers()
.then((result) => {
return {
props: {
users: result
}
}
})
.catch((error) => {
return {
props: {
error: error.message
}
}
})
}
Related
From the docs, this is how you fetch data, but since it's outside the function, how do I track the loading state so users can know when a data section is loading.
async function getData() {
const res = await fetch('https://api.example.com/...');
if (!res.ok) {
throw new Error('Failed to fetch data');
}
return res.json();
}
export default async function Page() {
const data = await getData();
return <main></main>;
}
You can use custom hooks for that:
useData.js
async function useData() {
const [loading, setLoading] = useState(true)
cost [error, setError] = useState(false)
const [data, setData] = useState()
useEffect(() => {
const fetchData = async () => {
setLoading(true)
const res = await fetch('https://api.example.com/...');
if (!res.ok) {
setError(true)
return
}
setError(false)
setLoading(false)
setData(res.json())
}
fetchData()
}, [])
return {loading, error, data}
}
//page
export default function Page() {
const {data, loading, error} = useData();
if(loading){ return <p>Loading...</p>}
if(error){ return <p>Error...</p>}
if(!data){ return <p>No data!!!</p>}
return <main></main>;
}
Later, you can set up your hook to use an uri param so you can reuse this hook in multiple pages.
In my social media app in Home page i want to dispatch 3 actions from my api:
posts , users , userDetails
But this may show an error(500) on vercel because the request takes a lot of time to get all these data.
vercel Error
this error will not appear again after refreshing the page !!!
i think that's because the request takes a lot of time to get all the data.
-> getServersideProps Code
export const getServerSideProps = wrapper.getServerSideProps(
store => async (context) =>
{
const {req} = context
const session = await getSession({ req });
await store.dispatch(fetchPostsAction());
await store.dispatch(fetchUsersAction(4));
await store.dispatch(LoggedInUserAction({email:session.user.email}));
})
-> fetchPostsAction Code
"post/list",
async (_, { rejectWithValue, getState, dispatch }) => {
try
{
let link = `${URL}/api/posts`;
const { data } = await axios.get(link,{
headers: { "Accept-Encoding": "gzip,deflate,compress" }
});
console.log("#2 got the data",data)
return data;
} catch (error) {
if (!error?.response) throw error;
return rejectWithValue(error?.response?.data);
}
}
);
-> extraReducer Code
builder.addCase(createpostAction.pending, (state, action) => {
state.createPostLoading = true;
});
builder.addCase(createpostAction.fulfilled, (state, action) => {
state.postLists = [...state.postLists, action.payload.post].sort((a, b) => b.createdAt > a.createdAt ? 1 : -1)
state.createPostLoading = false;
state.isCreated = true;
state.appErr = null;
state.serverErr = null;
});
builder.addCase(createpostAction.rejected, (state, action) => {
state.createPostLoading = false;
state.appErr =
action?.payload?.message || action?.payload?.error?.message;
state.serverErr = action?.error?.message;
});
-> get posts from api Code
handler.get(async (req, res) =>
{
await db.connect();
try {
const posts = await Post.find().populate({
path: 'user',
model: 'User',
}).populate({
path:'comments',
options: {sort: {'createdAt' : -1} }
}).sort('-createdAt')
res.status(200).json({
success:true,
posts
});
} catch (err) {
res.status(500).json(err.message)
}
await db.disconnect();
})
so what is the best way to fetch all these data in next js ?
I hope there is a way to solve this problem
I'm playing around with nextjs
and I've trouble to debug a function like
this:
export const authInitialProps = isProtectedRoute => {
console.log("mylog");// this works
return ({ req, res }) => {
console.log("inner my log", req); // this doesn't work
};
};
Using in a page
ProfilePage.getInitialProps = async () => {
const auth = authInitialProps(true);
if (!typeof auth === "function") {
const user = await getUserProfile();
return { user };
}
return { user: null };
};
I never see "inner my log" both in chrome console
and in my console terminal.
What's the problem please?
Try this It may work:
ProfilePage.getInitialProps = async () => {
const auth = await authInitialProps(true); // await added
if (!typeof auth === "function") {
const user = await getUserProfile();
return { user };
}
return { user: null };
};
I think it should be async to not pass over it!
Im trying to implement the authy-node phone verification with firebase functions and my app in react-native the message is sent to the correct mobile phone but for some reason the data I get back from the api is null any ideas out there
My Api firebase functions
import * as functions from 'firebase-functions';
const authy = require('authy')('mySecret');
export const getCode = functions.https.onCall((data, context) => {
const {
number, countryCode
} = data;
return authy.phones().verification_start(number, countryCode, { via:
'sms', locale: 'en', code_length: '4' }, (err: any, res: any) => {
if (err) {
throw new functions.https.HttpsError(err);
}
return res;
});
});
and this is my call from my app
export default class test extends Component {
constructor() {
super();
}
componentWillMount() {
const getCode = firebase.functions().httpsCallable('getCode');
getCode({number: 'theCorrectNumber', countryCode: '44'})
.then(function (result) {
const data = result;
console.log(data)
}).catch( function (error){
console.log(error)
})
}
render() {
return (
<View/>
);
}
}
Twilio developer evangelist here.
From what I can see in the Authy Node library that I'm assuming you're using, making a request to the API does not return a Promise. Instead it is built with request and responds to asynchronous requests using callbacks only. You do deal with the callback, but you are returning the result of calling the asynchronous function, which is null, rather than the result from the callback.
Perhaps including a callback as part of the function call would work better:
import * as functions from 'firebase-functions';
const authy = require('authy')('mySecret');
export const getCode = functions.https.onCall((data, callback) => {
const { number, countryCode } = data;
return authy
.phones()
.verification_start(
number,
countryCode,
{ via: 'sms', locale: 'en', code_length: '4' },
callback
);
});
You can then use it like this:
export default class test extends Component {
constructor() {
super();
}
componentWillMount() {
const getCode = firebase.functions().httpsCallable('getCode');
getCode({ number: 'theCorrectNumber', countryCode: '44' }, (err, res) => {
if (err) {
throw new functions.https.HttpsError(err);
}
const data = res;
console.log(data);
});
}
render() {
return <View />;
}
}
Let me know if that helps at all.
I have a middleware that can go to the refresh token before the next action runs and then run the other action when the access token expires.
But if I make more than one request at a time and the access token is over, I am trying to get as much refresh token as I am requesting. I am checking the isLoading property in state to prevent this. But after the request, isLoading value is true in the reducer, it seems to be false in the middleware, so it requests again and again.
I am sending refreshTokenPromise in fetching_refresh_token action, but I never get state.refreshTokenPromise, it is always undefined.
I definitely have a problem with the state.
So here is my question, how can I access the changing state value in middleware?
Refresh token middleware: (this version hits the endpoint multiple times)
import { AsyncStorage } from 'react-native';
import { MIN_TOKEN_LIFESPAN } from 'react-native-dotenv';
import moment from 'moment';
import Api from '../lib/api';
import {
FETCHING_REFRESH_TOKEN,
FETCHING_REFRESH_TOKEN_SUCCESS,
FETCHING_REFRESH_TOKEN_FAILURE } from '../actions/constants';
export default function tokenMiddleware({ dispatch, getState }) {
return next => async (action) => {
if (typeof action === 'function') {
const state = getState();
if (state) {
const expiresIn = await AsyncStorage.getItem('EXPIRES_IN');
if (expiresIn && isExpired(JSON.parse(expiresIn))) {
if (!state.refreshToken.isLoading) {
return refreshToken(dispatch).then(() => next(action));
}
return state.refreshTokenPromise.then(() => next(action));
}
}
}
return next(action);
};
}
async function refreshToken(dispatch) {
const clientId = await AsyncStorage.getItem('CLIENT_ID');
const clientSecret = await AsyncStorage.getItem('CLIENT_SECRET');
const refreshToken1 = await AsyncStorage.getItem('REFRESH_TOKEN');
const userObject = {
grant_type: 'refresh_token',
client_id: JSON.parse(clientId),
client_secret: JSON.parse(clientSecret),
refresh_token: refreshToken1,
};
const userParams = Object.keys(userObject).map(key => encodeURIComponent(key) + '=' + encodeURIComponent(userObject[key])).join('&');
const refreshTokenPromise = Api.post('/token', userParams).then(async (res) => {
await AsyncStorage.setItem('ACCESS_TOKEN', res.access_token);
await AsyncStorage.setItem('REFRESH_TOKEN', res.refresh_token);
await AsyncStorage.setItem('EXPIRES_IN', JSON.stringify(res['.expires']));
dispatch({
type: FETCHING_REFRESH_TOKEN_SUCCESS,
data: res,
});
return res ? Promise.resolve(res) : Promise.reject({
message: 'could not refresh token',
});
}).catch((err) => {
dispatch({
type: FETCHING_REFRESH_TOKEN_FAILURE,
});
throw err;
});
dispatch({
type: FETCHING_REFRESH_TOKEN,
refreshTokenPromise,
});
return refreshTokenPromise;
}
function isExpired(expiresIn) {
return moment(expiresIn).diff(moment(), 'seconds') < MIN_TOKEN_LIFESPAN;
}
Refresh token reducer:
import {
FETCHING_REFRESH_TOKEN,
FETCHING_REFRESH_TOKEN_SUCCESS,
FETCHING_REFRESH_TOKEN_FAILURE } from '../actions/constants';
const initialState = {
token: [],
isLoading: false,
error: false,
};
export default function refreshTokenReducer(state = initialState, action) {
switch (action.type) {
case FETCHING_REFRESH_TOKEN:
return {
...state,
token: [],
isLoading: true,
};
case FETCHING_REFRESH_TOKEN_SUCCESS:
return {
...state,
isLoading: false,
token: action.data,
};
case FETCHING_REFRESH_TOKEN_FAILURE:
return {
...state,
isLoading: false,
error: true,
};
default:
return state;
}
}
In the meantime, when I send it to the getState to refreshToken function, I get to the changing state value in the refreshToken. But in this version, the refresh token goes to other actions without being refreshed.
Monkey Patched version: (this version only makes 1 request)
import { AsyncStorage } from 'react-native';
import { MIN_TOKEN_LIFESPAN } from 'react-native-dotenv';
import moment from 'moment';
import Api from '../lib/api';
import {
FETCHING_REFRESH_TOKEN,
FETCHING_REFRESH_TOKEN_SUCCESS,
FETCHING_REFRESH_TOKEN_FAILURE } from '../actions/constants';
export default function tokenMiddleware({ dispatch, getState }) {
return next => async (action) => {
if (typeof action === 'function') {
const state = getState();
if (state) {
const expiresIn = await AsyncStorage.getItem('EXPIRES_IN');
if (expiresIn && isExpired(JSON.parse(expiresIn))) {
if (!state.refreshTokenPromise) {
return refreshToken(dispatch, getState).then(() => next(action));
}
return state.refreshTokenPromise.then(() => next(action));
}
}
}
return next(action);
};
}
async function refreshToken(dispatch, getState) {
const clientId = await AsyncStorage.getItem('CLIENT_ID');
const clientSecret = await AsyncStorage.getItem('CLIENT_SECRET');
const refreshToken1 = await AsyncStorage.getItem('REFRESH_TOKEN');
const userObject = {
grant_type: 'refresh_token',
client_id: JSON.parse(clientId),
client_secret: JSON.parse(clientSecret),
refresh_token: refreshToken1,
};
if (!getState().refreshToken.isLoading) {
const userParams = Object.keys(userObject).map(key => encodeURIComponent(key) + '=' + encodeURIComponent(userObject[key])).join('&');
const refreshTokenPromise = Api.post('/token', userParams).then(async (res) => {
await AsyncStorage.setItem('ACCESS_TOKEN', res.access_token);
await AsyncStorage.setItem('REFRESH_TOKEN', res.refresh_token);
await AsyncStorage.setItem('EXPIRES_IN', JSON.stringify(res['.expires']));
dispatch({
type: FETCHING_REFRESH_TOKEN_SUCCESS,
data: res,
});
return res ? Promise.resolve(res) : Promise.reject({
message: 'could not refresh token',
});
}).catch((err) => {
dispatch({
type: FETCHING_REFRESH_TOKEN_FAILURE,
});
throw err;
});
dispatch({
type: FETCHING_REFRESH_TOKEN,
refreshTokenPromise,
});
return refreshTokenPromise;
}
}
function isExpired(expiresIn) {
return moment(expiresIn).diff(moment(), 'seconds') < MIN_TOKEN_LIFESPAN;
}
Thank you.
I solved this problem using axios middlewares. I think is pretty nice.
import { AsyncStorage } from 'react-native';
import Config from 'react-native-config';
import axios from 'axios';
import { store } from '../store';
import { refreshToken } from '../actions/refreshToken'; // eslint-disable-line
const instance = axios.create({
baseURL: Config.API_URL,
});
let authTokenRequest;
function resetAuthTokenRequest() {
authTokenRequest = null;
}
async function getAuthToken() {
const clientRefreshToken = await AsyncStorage.getItem('clientRefreshToken');
if (!authTokenRequest) {
authTokenRequest = store.dispatch(refreshToken(clientRefreshToken));
authTokenRequest.then(
() => {
const {
token: { payload },
} = store.getState();
// save payload to async storage
},
() => {
resetAuthTokenRequest();
},
);
}
return authTokenRequest;
}
instance.interceptors.response.use(
response => response,
async (error) => {
const originalRequest = error.config;
if (
error.response.status === 401
&& !originalRequest._retry // eslint-disable-line no-underscore-dangle
) {
return getAuthToken()
.then(() => {
const {
token: {
payload: { 'access-token': accessToken, client, uid },
},
} = store.getState();
originalRequest.headers['access-token'] = accessToken;
originalRequest.headers.client = client;
originalRequest.headers.uid = uid;
originalRequest._retry = true; // eslint-disable-line no-underscore-dangle
return axios(originalRequest);
})
.catch(err => Promise.reject(err));
}
return Promise.reject(error);
},
);
export default instance;
If you have a problem, do not hesitate to ask.
you could benefit from redux-sagas
https://github.com/redux-saga/redux-saga
redux-sagas is just background runner which monitors your actions and can react when some specific action is met. You can listen for all actions and react to all or you can react to only latest as mentioned in comments
https://redux-saga.js.org/docs/api/#takelatestpattern-saga-args
while redux-thunk is just another way to create actions on the go and wait for some I/O to happen and then create some more actions when I/O is done. It's more like synced code pattern and redux-sagas is more like multi-threaded. On main thread you have your app running and on background thread you have sagas monitors and reactions