I am hosting a react app in aws amplify using the aws-serverless version of express as the REST API, which sits inside of a lambda function. A big problem that I am facing is that asynchronous jobs in aws-serverless express cause the lambda function to complete before the promises resolve. Leaving me with no data and no error handling. This caused me to bring a lot of the asynchronous work to the front end of the application.
The problem here is that I need to bring a large amount of data into state. Right now, I am using a delay workaround (shown below) but instead need a programatic way to make sure state is finished updating before being used in the second useEffect hook (dependent on odds & failedTries props) instead of using the delay functionality.
Any help would be greatly appreciated.
const App = ({ signOut }) => {
const [odds, setOdds] = useState([]);
const [updateTime,setUpdateTime] = useState(0);
const [failedTries,setFailedTries] = useState(0);
useEffect(() => {
const setNflOdds = async () => {
let response = await updateNflOdds();
let data = response;
setOdds(data);
};
setNflOdds();
setUpdateTime(1);
const interval = setInterval(() => {
setNflOdds();
setUpdateTime(updateTime => updateTime +1);
}, 100000);
return () => clearInterval(interval);
}, []);
useEffect(() => {
const s3Push = (() => {
if(!odds.length) {
setFailedTries(failedTries => failedTries + 1);
} else {
const delay = ms => new Promise(res => setTimeout(res, ms));
const nflOddsRefDelay = async() => {
*//This is the current workaround, wait ten seconds before pushing odds state up to the s3 bucket*
await delay(10000);
oddsS3Helper(odds);
};
nflOddsRefDelay()
}
});
s3Push();
}, [odds, failedTries]);
With the above indicated delay workaround this works for my use case (13k records inside of the array) but the data size is highly variable and I want to figure out a way that no matter the data size it brings the entire call up to the s3 bucket.
below is the content of the functions being called in the useEffect hook
const pushToS3 = async ( file, key ) => {
const creds = await Auth.currentCredentials()
const REGION = {region};
const s3Client = new S3Client({
credentials: Auth.essentialCredentials(creds),
region: REGION
});
const params = {
Bucket: {s3 bucket name}
Key: key,
Body: file,
};
s3Client.send(new PutObjectCommand(params));
console.log("file is sent");
};
const oddsS3Helper = (async (odds) => {
console.log("inside s3 helper: ",odds);
let csv = '';
let headers = Object.keys(odds[0]).join(',');
let values = odds.map(odd => Object.values(odd).join(',')).join('\n');
csv += headers + '\n' + values;
const buffedFile = csv;
const key = 'nflprops.csv'
const delay = ms => new Promise(res => setTimeout(res, ms));
const propRefDelay = async() => {
await delay(5000);
await postNflOdds();
};
pushToS3( buffedFile, key );
await propRefDelay();
});
async function getNflGames() {
const apiName = {name of serverless API inside of lambda};
const path = {path name};
const init = {
headers: {} // OPTIONAL
};
const data = await API.get(apiName, path, init);
return data;
};
async function getNflOdds(gameId) {
const apiName = {name of serverless API inside of lambda};
const path = {path name};
const init = {
headers: {}, // OPTIONAL
body: { gameId }
};
const data = await API.post(apiName, path, init);
return data;
};
async function updateNflOdds() {
const ojNflGames = await getNflGames();
const nflGameProps = [];
const nflOddsPush = ( async () => {
try {
await ojNflGames.data.map( async (game) => {
const ojNflOdds = await getNflOdds(game.id)
await ojNflOdds.data[0].odds.map((line) => {
nflGameProps.push(
{
gameId: game.id,
oddsId: line.id,
sports_book_name: line.sports_book_name,
name: line.name,
price: line.price,
checked_date: line.checked_date,
bet_points: line.bet_points,
is_main: line.is_main,
is_live: line.is_live,
market_name: line.market_name,
home_rotation_number: line.home_rotation_number,
away_rotation_number: line.away_rotation_number,
deep_link_url: line.deep_link_url,
player_id: line.player_id,
}
);
});
});
} catch (err) {
console.log("there was an error", err);
}
});
try {
await nflOddsPush();
} catch(err) {
console.log("odds push errored: ", err);
}
console.log("inside of updateNflOdds function: ",nflGameProps);
return nflGameProps;
};
Related
This code is designed to recursively iterate through a selected directory using the file system access api , and sent it via axios post request.
I have an encountered 2 problems :
I am struggling to find the right way to to enter subdirectories (now it only works for a directory with only files and no subDirs)
as you can see , i set a timeout before the post request , for some reason I cant identify , the promise in savedOCS function , probably resolves before it should.
I have the following code :
async uploadDirectory () {
const directoryHandle = await window.showDirectoryPicker();
const t0 = performance.now();
console.log(`t0 ${t0}`);
this.setState({chosenDirectory: directoryHandle.name} , ()=> {
console.log(this.state.chosenDirectory);
});
await this.handleDirectoryEntry(directoryHandle);
const t4 = performance.now();
console.log(`t4 ${t4}`);
setTimeout(() => {
this.axios.post(
'/DirectoryTransfer', {
directory: this.state.chosenDirectory,
directoryFiles: this.state.directoryFiles
}
).then((resData) => {
// this.fetchRemoteFileSystem();
const t5 = performance.now();
console.log(`t5 ${t5}`);
}).catch((error) => {
console.log(error)
})
}, 5000);
}
async handleDirectoryEntry(directoryHandle,subdir) {
let fileEntries = [];
console.log(directoryHandle);
for await (const entry of directoryHandle.values()) {
console.log(entry);
if(entry.kind === "file" && subdir === '') {
fileEntries.push(await entry.getFile());
}
}
console.log(fileEntries);
await this.saveDocs(fileEntries);
}
saveDocs = async (files) => {
const filePromises = files.map((file) => {
return new Promise ((resolve ,reject)=> {
const fileReader = new FileReader();
fileReader.onload = async ()=> {
try {
let directoryFiles = this.state.directoryFiles || [];
console.log('before setState: ', directoryFiles)
let response = false;
const t2 = performance.now();
console.log(`t2 ${t2}`)
await this.setState(
(prevState) => ({
directoryFiles: [...prevState.directoryFiles, { name: file.name, data: fileReader.result }]
}),
() => {
response = true;
console.log("after setState: ", this.state.directoryFiles);
const t3 = performance.now();
console.log(`t3 ${t3}`)
}
);
resolve(response);
} catch(err) {
reject(err)
}
}
fileReader.onerror = (err) => {
reject(err);
}
fileReader.readAsText(file);
})
})
const fileInfos = await Promise.all(filePromises);
return fileInfos;
}
i tried to find a way to iterate subDirs using recursion , and to async read files inside a directory.
current results :
the code reads the files fine.
without the timeout it sends a post request with an empty array of files.
doesn't have an implementation for subDirs.
So i have this function that i want to run once when the app start. This function task is to create userId then i will run another function to fetch data from firebase with the userId that created before. But the fetch function didn't start or it didnt do the task well, there is no sign of error, that's what make it more confusing. If i press the fetch function by button it work correctly.
the state
const [task, setTask] = useState(); // bisa di sebut sebagai controller text input
const [taskItems, setTaskItems] = useState([]); // state untuk list task
const [userId, setUserId] = useState();
const [isLoading, setIsLoading] = useState(true);
const baseUrl =
'https://react-http-post-RANDOM_KEY-default-rtdb.firebaseio.com/task/' + userId;
this is function to create userId function on init app
const handleCreateUser = async () => {
setIsLoading(true);
try {
const value = await AsyncStorage.getItem('userId');
if (value !== null) {
setUserId(value);
} else {
const uniqueId = makeid(6);
await AsyncStorage.setItem('userId', 'user' + uniqueId);
setUserId('user' + uniqueId);
}
await fetchDatabase();
} catch (error) {
console.log('errorrr AsyncStorage' + error);
}
setIsLoading(false);
};
this is function to fetch data from firebase
const fetchDatabase = async () => {
console.log('infinite looping');
try {
const response = await fetch(baseUrl + '.json');
if (!response.ok) {
throw new Error('Something went wrong!');
}
const data = await response.json();
// looping Map/Object dengan key sebagai indexnya
const loadedTask = [];
for (var id in data) {
loadedTask.push({
key: id,
text: data[id].text,
isComplete: data[id].isComplete,
});
}
setTaskItems(loadedTask);
} catch (error) {
setError(error.message);
}
};
this is how i call the useEffect
useEffect(() => {
handleCreateUser();
}, []);
The first thing I see is that you are not using await correctly. It should be before fetchDatabase(); function that is inside handleCreateUser like so:
await fetchDatabase();
The word await is there when you have to call an asynchronous function and you have to wait for this function to be completed.
Edit
To use only one useEffect you can check if your fetch function received your data by:
// or whatever statusCode you get when the data are present
if(reponse.statusCode === 200) {
// the await is not needed because it is present for the reponse abov
const data = response.json();
// looping Map/Object dengan key sebagai indexnya
const loadedTask = [];
for (var id in data) {
loadedTask.push({
key: id,
text: data[id].text,
isComplete: data[id].isComplete,
});
}
setTaskItems(loadedTask);
}
i got the answer, by using 2 useEffect
useEffect(() => {
handleCreateUser();
}, []);
useEffect(() => {
fetchDatabase();
}, [userId]);
My .net core react web application works fine, except that when I try to publish it gives me the following error:
Occurred while linting C:\.....Fetch.js: 79
Rule: "react-hooks/exhaustive-deps"
This is my code:
const populateTable1Data = async () => {
var response = await axios.get(apiurl + { params: { id: props.id1 } });
var data = await response.data;
setTable1Data(data);
}
const populateTable2Data = async () => {
var response = await axios.get(apiurl + { params: { id: props.id2 } });
var data = await response.data;
setTable2Data(data);
setLoading(false);
}
useEffect(() => {
const load = async () => {
await populateTable1Data();
await populateTable2Data();
setLoading(false)
}
load()
}, []);
Problem is that I have a very similar useEffect inside another component which doesn't give errors though:
const populateTableData = async () => {
const response = await axios.get(apiurl + key);
const data = await response.data;
setTableData(data);
setLoading(false);
}
useEffect(() => {
populateTableData();
}, [])
If anyone has the same problem, I solved by doing this:
const populateTable1Data = async (dataProps) => {
var response = await axios.get(apiurl + { params: { id: dataProps.id1 } });
var data = await response.data;
setTable1Data(data);
}
const populateTable2Data = async (dataProps) => {
var response = await axios.get(apiurl + { params: { id: dataProps.id2 } });
var data = await response.data;
setTable2Data(data);
setLoading(false);
}
useEffect(() => {
const load = async () => {
await populateTable1Data(props);
await populateTable2Data(props);
setLoading(false)
}
load()
}, [props]);
I essentially passed the props on the function call, I don't know why does it have to be this way, I'll leave the answer here in case anyone else needs it while waiting for someone to be kind enought to explain the reason for this.
I wanna add multiple photo to db by Array.map() and after that add Array with url storage to collection.
I have problem with async function, because i should wait for this function await addImages() but something is not good.
const addImages = async () => {
image.map(async (imagePhoto) => {
const childPath = `post/${firebase.auth().currentUser.uid}/${Math.random().toString(36)}`;
const response = await fetch(imagePhoto);
const blob = await response.blob();
const task = firebase
.storage()
.ref()
.child(childPath)
.put(blob);
const taskProgress = snapshot => {
console.log(`transferred: ${snapshot.bytesTransferred}`)
}
const taskCompleted = () => {
task.snapshot.ref.getDownloadURL().then((snapshot) => {
imageDB.push(snapshot)
})
}
const taskError = snapshot => {
console.log(snapshot)
}
task.on("state_changed", taskProgress, taskError, taskCompleted);
})
}
const addToDbServices = async () => {
await addImages();
firebase.firestore().collection("services")
.doc(firebase.auth().currentUser.uid)
.collection("userServices")
.add({
nameService,
errorCode,
description,
imageDB,
status,
creation: firebase.firestore.FieldValue.serverTimestamp()
}).then(() => {
Alert.alert('Serwis', 'Twoje zgłoszenie zostało pomyślnie dodane'),
navigation.goBack()
})
}
image.map(async (imagePhoto) => {...})
This creates an array of promises. These are executed but not awaited by default, so code execution continues regardless whether the operations are finished or not. If you want to await all these promises you can use Promis.all() like that:
const addImages = async () => {
const pendingOperations = image.map(async (imagePhoto) => {...});
// wait until all images are processed
return Promise.all(pendingOperations); // or await Promise.all(pendingOperations);
}
const addToDbServices = async () => {
await addImages();
...
}
As described in comments between my code snippet, the asynchronicity is not working as expected. For each id, an object/item should return but it only returns one item since my async await isn't implemented properly. What could be a possible workaround?
Thanks in advance
useEffect(() => {
axios.get('url-here').then((res) => {
res.data.favProperties?.map((el) => {
console.log(el) // this returns multitple id's of saved/liked items
axios.get('url-here').then(async (r) => {
if (r.data) {
console.log(r.data) // Problem starts here
// This returns the full object of the liked items
// But only one object is returned, not every object for which an id was stored
await storageRef
.child(r.data.firebaseRef + '/' + r.data.images[0])
.getDownloadURL()
.then((url) => {
// Here i need to fetch the image for each object
console.log(url)
})
.catch((err) => console.log(err))
}
})
})
})
}, [])
I think breaking down your operations into functions will prevent this Promise Hell. I would recommend using async await for these kinda operations. Also I was confused about the last part of console logging the download URL, by my guess you're trying to save all the download URLs for these liked items in an array.
useEffect(() => {
firstFunction();
}, []);
const firstFunction = async () => {
const { data } = await axios.get("url-here");
const favProperties = data.favProperties;
const fetchedUrls = await Promise.all(
favProperties?.map(async (el) => (
await secondFunction(el.id) /** use el to pass some ID */
))
);
};
const secondFunction = async (someId) => {
/** your second URL must point to some ID (or some parameters) specific API otherwise
running same op in a loop without variations doesn't make any sense */
const { data } = await axios.get(`some-other-url/${someId}`);
if (data) {
console.log(data);
const fetchedUrl = await storageThing(data);
return fetchedUrl;
}
};
const storageThing = async ({ firebaseRef, images }) => {
try {
const downloadURL = await storageRef
.child(firebaseRef + "/" + images[0])
.getDownloadURL();
console.log(downloadURL);
return downloadURL;
} catch (error) {
console.log(error);
return '';
}
};