I'm working on a blockchain project and currently facing the interaction between front-end (react) and smartcontract. I need to retrieve my places that have been pushed on the blockchain to show them on the website:
The smart contract piece that I'm interested interacting to atm:
contract Prenotation {
struct Place{
string name;
string description;
bool isActive; //tells if the place is active
uint256 price; //price per day in wei
address owner; //owner of the place
//keeps score if the place is booked on a particular day
//example: isBooked[4] will denote that the place has been booked on th 3th of Jan
//example 2: isBooked[31] -> the place is booked for the 1th of Feb
bool[] isBooked;
}
//Sequential unique placeId for every new Place
uint256 public placeId;
mapping(uint256 => Place) public places;
...
That's how I tried to retrieve those Places (inside PrenotationContext.jsx):
const getEthereumContract = () => {
const provider = new ethers.providers.Web3Provider(ethereum);
const signer = provider.getSigner();
const prenotationContract = new ethers.Contract(contractAddress, contractABI, signer);
return prenotationContract;
}
export const PrenotationProvider = ({children}) => {
...
const [places, setPlaces] = useState([]);
...
const fetchAllPlaces = async () => {
try {
if(!ethereum) return alert("Please install MetaMask");
const prenotationContract = getEthereumContract();
const placeId = await prenotationContract.methods.placeId().call()
console.log(placeId)
//return object containing places object
const places = [];
for (var i = 0; i < placeId; i++) {
const place = await prenotationContract.methods.places(i).call();
places.push({
id: i,
name: place.name,
description: place.description,
price: parseInt(place.price._hex) / (10 ** 18)
})
}
setPlaces(places)
} catch (error) {
console.log(error);
throw new Error("No ethereum object");
}
}
I fall into the catch with this error:
TypeError: Cannot read properties of undefined (reading 'placeId')
at fetchAllPlaces (PrenotationContext.jsx:55:57)
at checkIfWalletConnected (PrenotationContext.jsx:82:31)
I tried to verify if I correctly retrieve the contract and logging it on console after calling getEthereumContract I can successfully see it.
Contract inside the web console
In the checkIfWalletConnected I simply call the fetchAllPlaces method.
It's my first project working with solidity, react and all this so I really don't know how to solve it.
In your current for implementation, if extracting fails in the middle of the operation, you are not going to get all places, you will get some of them. Instead
let places
try{
// check if placeId is a string or number. I think Should be string
const placeId = await prenotationContract.methods.placeId().call()
places = await Promise.all(
// since your for loop is till placeId
Array(parseInt(placeId))
.fill()
.map((element, index) => {
// since places is public, solidity assgins a getter automatically
return prenotationContract.methods.places(index).call();
})
);
} catch (e) {
console.log("error in extracting places", e);
}
Related
I am trying to make barbershop web app where costumer can see list of free appointments and when they reserve free appointment I want to delete that field from firebase.
I have a collection which represents one barber.
This is how it looks in firebase.
As you see radno_vrijeme is object or map in firebase which contains 6 arrays, and in each array there is list of free working hours.
In my function I am able to do everthing except last line where I need to update firebase collection.
const finishReservation = async () => {
try {
const freeTimeRef = collection(db, `${barber}`);
const q = query(freeTimeRef);
const querySnap = await getDoc(q);
querySnap.forEach(async (doc) => {
const radnoVrijeme = doc.data().radno_vrijeme;
// Find the index of the hour you want to delete
const index = radnoVrijeme["Mon"].indexOf(hour);
// Remove the hour from the array
radnoVrijeme["Mon"].splice(index, 1);
// Update the document in the collection
console.log(radnoVrijeme);
const radnoVrijemeMap = new Map(Object.entries(radnoVrijeme));
await freeTimeRef.update({ radno_vrijeme: radnoVrijemeMap });
});
} catch (error) {
console.log(error);
}
};
I tried to pass it as JSON stringified object, but it didn't work. I always get this error :
"FirebaseError: Expected type 'ya', but it was: a custom Ia object"
When you are trying to fetch multiple documents using a collection reference or query, then you must use getDocs():
const finishReservation = async () => {
try {
const freeTimeRef = collection(db, `${barber}`);
const q = query(freeTimeRef);
const querySnap = await getDocs(q);
const updates = [];
querySnap.forEach((d) => {
const radnoVrijeme = d.data().radno_vrijeme;
const index = radnoVrijeme["Mon"].indexOf(hour);
radnoVrijeme["Mon"].splice(index, 1);
const radnoVrijemeMap = new Map(Object.entries(radnoVrijeme));
updates.push(updateDoc(d.ref, { radno_vrijeme: radnoVrijemeMap }))
});
await Promise.all(updates);
console.log("Documents updated")
} catch (error) {
console.log(error);
}
};
getDoc() is used to fetch a single document using a document reference.
Context
I'm retrieving data from the ESPN API to fetch weekly NFL matchup data. So, I'm making 18 api calls each time I need to fetch this data to account for all 18 weeks in the NFL season. I'm then creating an array with the data I need from the responses to those calls and writing out 18 files that align with each week in the NFL season (week1.json, week2.json, etc.).
Problem
The problem is that when I call my endpoint, I am seeing 2 things intermittently, and not necessarily at the same time:
(1) Some of the json files(week1.json, week2.json, etc.) include only a portion of the expected array. So, instead of 16 objects in the array, I may see only 4, or only 6, etc. Why would I only see a portion of the response data written to the array that's ultimately written to the .json files?
(2) Not all files are written to each time the endpoint is called. So, I may see that only week1-week5's .json files are written. Why aren't all of them updated?
Problem Code
// iterate 18 times
for (let i = 0; i < 18; i++) {
let weekNumber;
weekNumber = i + 1;
const week = fs.readFileSync(`./pickem/week${weekNumber}.json`, 'utf8');
const weekJson = JSON.parse(week);
// empty weekJson.games array
weekJson.games = []
// get all items
axios.get(`https://sports.core.api.espn.com/v2/sports/football/leagues/nfl/seasons/2022/types/2/weeks/${weekNumber}/events?lang=en®ion=us`)
.then(response => {
const schedule = [];
// get all items from response
const items = response.data.items
// console.log(response.data.items)
items.forEach(item => {
// make get call to $ref
axios.get(item.$ref)
.then(response => {
// get name
const name = response.data.name
// get date
const date = response.data.date
// get event id
const eventid = response.data.id
// get team ids
let team1 = response.data.competitions[0].competitors[0].id
let team2 = response.data.competitions[0].competitors[1].id
// create new object
const newObject = {
name: name,
date: date,
eventid: eventid,
team1: team1,
team2: team2
}
// add games for week
weekJson.games.push(newObject);
fs.writeFileSync(`./pickem/week${weekNumber}.json`, JSON.stringify(weekJson));
})
.catch(error => {
console.log(error)
})
})
}).catch(error => {
console.log(error)
})
}
Updated Code
router.get('/getschedules', (req, res) => {
async function writeGames() {
// iterate 18 times
for (let i = 0; i < 18; i++) {
let weekNumber;
weekNumber = i + 1;
const week = fs.readFileSync(`./pickem/week${weekNumber}.json`, 'utf8');
const weekJson = JSON.parse(week);
// empty weekJson.games array
weekJson.games = []
// get all items
// Add await keyword to wait for a week to be processed before going to the next one
await axios.get(`https://sports.core.api.espn.com/v2/sports/football/leagues/nfl/seasons/2022/types/2/weeks/${weekNumber}/events?lang=en®ion=us`)
.then(async (response) => { // add async to be able to use await
const schedule = [];
// get all items from response
const items = response.data.items
console.log(response.data.items)
// Use standard loop to be able to benefit from async/await
for (let item of items) {
// make get call to $ref
// wait for an item to be processed before going to the next one
await axios.get(item.$ref)
.then(response => {
// get name
const name = response.data.name
// get date
const date = response.data.date
// get event id
const eventid = response.data.id
// get team ids
let team1 = response.data.competitions[0].competitors[0].id
let team2 = response.data.competitions[0].competitors[1].id
// create new object
const newObject = {
name: name,
date: date,
eventid: eventid,
team1: team1,
team2: team2
}
// add games for week
weekJson.games.push(newObject);
})
.catch(error => {
console.log(error)
})
}
// moved out of the for loop since you only need to write this once
fs.writeFileSync(`./pickem/week${weekNumber}.json`, JSON.stringify(weekJson));
}).catch(error => {
console.log(error)
})
}
}
writeGames();
})
Your issue might come from the fact that you are looping over an array of item that triggers parallel asynchronous calls and write weekJson before you get the entire data. (But theoretically your code should work if writeSyncFile is really synchronous, maybe there are locks on the file system that prevents node to write properly?)
You could try to make everything sequential and only write weekJson once instead of everytime you go over an item:
EDIT
I updated my original code proposition by keeping parallel calls and it worked for me (it's similar to OP's code but I only write the json file once per week).
Then I tried to run OP's code and it was working fine as well. So this makes me think that the problem isn't from the code itself but rather how it's called. As a pure node script, there doesn't seem to be any issue. But I just noticed that OP is using it server side as the result of an API call.
Having an API write so many JSON concurrently is probably not the best idea (especially if the api is called multiple times almost simultaneously). You could either
just return the games in the response
or precompute the results
or fetch and write them only once then cache the result to be reused
Then I wonder if due to the server context, there is not some kind of timeout since OP said that with my initial solution, only the first week was created.
const axios = require("axios");
const fs = require("fs");
async function writeGames() {
const writeWeekGamesPromises = [];
// iterate 18 times
for (let weekNumber = 1; weekNumber < 19; weekNumber++) {
// give week a default value in case the json file doesn't exist (for repro purpose)
let week = "{}";
try {
week = fs.readFileSync(`./pickem/week${weekNumber}.json`, "utf8");
} catch (e) {
console.log(`error reading week ${weekNumber} json file:`, e);
// file doesn't exist yet
}
const weekJson = JSON.parse(week);
// empty weekJson.games array
const games = [];
weekJson.games = games;
// get all items
// Add await keyword to wait for a week to be processed before going to the next one
writeWeekGamesPromises.push(axios
.get(
`https://sports.core.api.espn.com/v2/sports/football/leagues/nfl/seasons/2022/types/2/weeks/${weekNumber}/events?lang=en®ion=us`
)
.then(async (eventListResponse) => {
// add async to be able to use await
const schedule = [];
console.log(JSON.stringify(eventListResponse.data),'\n');
// get all items from response
const items = eventListResponse.data.items;
// console.log(eventListResponse.data.items); // this seems to be useless since we log the whole data just above
// parallelize calls and wait for all games from a week to be fetched before writing the file
await Promise.all(
items.map((item) => {
// we return the promise so that Promise.all will wait for all games to be pushed before going on writing the file
return axios
.get(item.$ref)
.then((response) => {
// get name, date and eventid
const {name, date, id: eventid} = response.data;
// get team ids
let team1 = response.data.competitions[0].competitors[0].id;
let team2 = response.data.competitions[0].competitors[1].id;
games.push({ name, date, eventid, team1, team2 });
})
.catch((error) => {
console.log(error);
});
})
);
// Now that all game data is ready, write in the file
fs.writeFileSync(
`./pickem/week${weekNumber}.json`,
JSON.stringify(weekJson)
);
})
.catch((error) => {
console.log(error);
}));
}
// Waiting for all games from all weeks to be processed
await Promise.all(writeWeekGamesPromises);
}
async function runAndLogTime() {
const start = Date.now();
await writeGames();
console.log(`took ${(Date.now() - start) / 1000}s to write all json files`);
}
runAndLogTime();
I am trying to create a script that pulls from the coin market cap API and displays the current price. The script is working fine on the back end when I assign the variable a value. However, when I try to run the function on sheets the returned value is null.
function marketview(ticker) {
var url = "https://pro-api.coinmarketcap.com/v1/cryptocurrency/quotes/latest?CMC_PRO_API_KEY=XXX&symbol=" + ticker;
var data = UrlFetchApp.fetch(url);
const jsondata = JSON.parse(data);
Logger.log(jsondata.data[ticker].quote['USD'].price)
}
My execution logs show that the scripts are running, but when when I use the function and try and quote ETH for example, the script is running for BTC.
When I do this on the backend and assign ETH the script works fine and returns the right quote. Any ideas on what I'm missing?
I did the same with coingecko API and add an issue having all my requests being rejected with quota exceeded error.
I understood that Google sheets servers IPs address were already spamming coingecko server. (I was obviously not the only one to try this).
This is why I used an external service like apify.com to pull the data and re-expose data over their API.
This is my AppScripts coingecko.gs:
/**
* get latest coingecko market prices dataset
*/
async function GET_COINGECKO_PRICES(key, actor) {
const coinGeckoUrl = `https://api.apify.com/v2/acts/${actor}/runs/last/dataset/items?token=${key}&status=SUCCEEDED`
return ImportJSON(coinGeckoUrl);
}
You need ImportJSON function, available here: https://github.com/bradjasper/ImportJSON/blob/master/ImportJSON.gs
Then in a cell I write: =GET_COINGECKO_PRICES(APIFY_API_KEY,APIFY_COINGECKO_MARKET_PRICES), you will have to create two field named APIFY_API_KEY and APIFY_COINGECKO_MARKET_PRICES in order for this to work.
Then register on apify.com, then you'll have to create an actor by forking apify-webscraper actor.
I set the StartURLs with https://api.coingecko.com/api/v3/coins/list, this will give me the total number of existing crypto (approx 11000 as of today), and number of page so I can run the request concurrently (rate limit is 10 concurrent requests on coingecko), then I just replace /list with /market and set the proper limit to get all the pages I need.
I use the following for the tasks page function:
async function pageFunction(context) {
let marketPrices = [];
const ENABLE_CONCURRENCY_BATCH = true;
const PRICE_CHANGE_PERCENTAGE = ['1h', '24h', '7d'];
const MAX_PAGE_TO_SCRAP = 10;
const MAX_PER_PAGE = 250;
const MAX_CONCURRENCY_BATCH_LIMIT = 10;
await context.WaitFor(5000);
const cryptoList = readJson();
const totalPage = Math.ceil(cryptoList.length / MAX_PER_PAGE);
context.log.info(`[Coingecko total cryptos count: ${cryptoList.length} (${totalPage} pages)]`)
function readJson() {
try {
const preEl = document.querySelector('body > pre');
return JSON.parse(preEl.innerText);
} catch (error) {
throw Error(`Failed to read JSON: ${error.message}`)
}
}
async function loadPage($page) {
try {
const params = {
vs_currency: 'usd',
page: $page,
per_page: MAX_PER_PAGE,
price_change_percentage: PRICE_CHANGE_PERCENTAGE.join(','),
sparkline: true,
}
let pageUrl = `${context.request.url.replace(/\/list$/, '/markets')}?`;
pageUrl += [
`vs_currency=${params.vs_currency}`,
`page=${params.page}`,
`per_page=${params.per_page}`,
`price_change_percentage=${params.price_change_percentage}`,
].join('&');
context.log.info(`GET page ${params.page} URL: ${pageUrl}`);
const page = await fetch(pageUrl).then((response) => response.json());
context.log.info(`Done GET page ${params.page} size ${page.length}`);
marketPrices = [...marketPrices, ...page];
return page
} catch (error) {
throw Error(`Fail to load page ${$page}: ${error.message}`)
}
}
try {
if (ENABLE_CONCURRENCY_BATCH) {
const fetchers = Array.from({ length: totalPage }).map((_, i) => {
const pageIndex = i + 1;
if (pageIndex > MAX_PAGE_TO_SCRAP) {
return null;
}
return () => loadPage(pageIndex);
}).filter(Boolean);
while (fetchers.length) {
await Promise.all(
fetchers.splice(0, MAX_CONCURRENCY_BATCH_LIMIT).map((f) => f())
);
}
} else {
let pageIndex = 1
let page = await loadPage(pageIndex)
while (page.length !== 0 && page <= MAX_PAGE_TO_SCRAP) {
pageIndex += 1
page = await loadPage(pageIndex)
}
}
} catch (error) {
context.log.info(`Fetchers failed: ${error.message}`);
}
context.log.info(`End: Updated ${marketPrices.length} prices for ${cryptoList.length} cryptos`);
const data = marketPrices.sort((a, b) => a.id.toLowerCase() > b.id.toLowerCase() ? 1 : -1);
context.log.info(JSON.stringify(data.find((item) => item.id.toLowerCase() === 'bitcoin')));
function sanitizer(item) {
item.symbol = item.symbol.toUpperCase()
return item;
}
return data.map(sanitizer)
}
I presume you are hiting the same issue I had with coinmarketcap, and that you could do the same with it.
You're not return ing anything to the sheet, but just logging it. Return it:
return jsondata.data[ticker].quote['USD'].price
I want to execute a function which consists of multiple sub-queries operating in multiple collections. They are then executed in Promise.all(). The problem is, that changes made by the first query are saved to the db even if the second or third query might fail (e.g. bonus is null). How could I prevent that from happening?
Some context: The purpose of this function is to track the transactions in which customers (who collect points in a loyalty program) cash in collected points to get the selected bonus in exchange.
export const addNewBonus = (req,res) => {
let newBonus = new Bonus(req.body)
//save new Bonus into database
var f1 = newBonus.save()
//increment timesChosen for the selected bonus of the involved shop
var f2 = Shop.findOne({ "_id": req.body.shopId})
.then((shop) => {
const bonus = shop.bonuses.id(req.body.bonusId)
if(bonus == null) throw "Bonus with specified bonusID not found for this shop";
else bonus.timesChosen = bonus.timesChosen + 1
return shop.save()
})
//update user's points
var f3 = User.findOne({ "_id": req.body.userId})
.then((user) => {
const currentPointAmount = user.pAmount;
if(currentPointAmount < req.body.bonusPrice) throw "Not enough Points on user account to choose this bonus"
else{
user.pAmount = user.pAmount - req.body.bonusPrice
}
return user.save()
});
Promise.all([f1, f2, f3])
.then(results => {
res.send(results)
})
.catch( err => {res.send(err)})
}
I'm trying to create a simple example of payments over the XRPL using Ripple-lib. The idea is to send several payments to different accounts stored in an array. I've made it kind of work in a different way as it is expected, but when using the 'then' method (as the docs recommend) does not work at all.
I'm a total newbie to Javascript so I don't have a good grasp on the language nor asyncronous coding and promises. When using the 'then' paradigm, the code stops working and no output can be seen in the console. This is the code I'm currently using. In the comments inside the 'SendXRP' function I explain the problem. How can this be re-arranged? Between the two ways, what is the proper one to code it?
'use strict';
const RippleAPI = require('ripple-lib').RippleAPI;
const sender = 'r*********************************';
const secret = 's****************************';
const destinations = ['r*********************************',
'r*********************************',
'r*********************************'];
const amount = 5;
// Instantiate Ripple API
const api = new RippleAPI({
server: "wss://s.altnet.rippletest.net:51233"
});
run();
async function sendXRP(amount, fee, destination, memo) {
// Update amount
amount = (amount - fee).toString();
// Build payment
const payment = {
source: {
address: sender,
maxAmount: {
value: amount,
currency: 'XRP'
}
},
destination: {
address: destination,
amount: {
value: amount,
currency: 'XRP'
}
},
memos: [
{
data: memo
}
]
};
// Build instuctions
const instructions = {
maxLedgerVersionOffset: 5
};
console.log('Sending ' + amount + ' to ' + destination);
// THIS KIND OF WORKS FOR NOW
// Prepare the payment
const preparedTX = await api.preparePayment(sender, payment, instructions);
// Sign the payment
const signedTX = api.sign(preparedTX.txJSON, secret);
// Submit the payment
const result = await api.submit(signedTX['signedTransaction']);
// Return TX hash on successful TX
if ('resultCode' in result && result['resultCode'] == 'tesSUCCESS') {
return signedTX.id;
} else {
return null;
}
// THIS IS MORE SIMILAR TO HOW IT IS DONE IN THE DOCS! NOT WORKING!
// ALSO, HOW DO I RETURN THE RESULT OF API.SIGN TO THE MAIN FUNCTION?
// Prepare the payment
// api.preparePayment(sender, payment, instructions).then(preparedTX => {
// // Sign the payment
// api.sign(preparedTX.txJSON, secret).then(signedTX => {
// // Submit the payment
// api.submit(signedTX['signedTransaction']);
// })
// }).catch(console.error);
}
function run() {
// Connect to Ripple server
api.connect().then(() => {
return api.getFee();
}).then(async fee => {
for (var i in destinations) {
var hash = await sendXRP(amount, Number(fee), destinations[i], 'memotext');
console.log(hash);
}
}).then(() => {
return api.disconnect();
}).catch(console.error);
}
Could it be that some of the transactions failed to send? If it failed, the result variable from sendXRP should have the txresult, but since you returned null if the result code is not tesSUCCESS, it doesn't return the result information.
const result = await api.submit(signedTX['signedTransaction']);
if ('resultCode' in result && result['resultCode'] == 'tesSUCCESS') {
return signedTX.id;
} else {
return null;
}
Before, when I tried submitting transactions consecutively, it would fail and return error code tefPAST_SEQ.
"The sequence number of the transaction is lower than the current sequence number of the account sending the transaction." from https://developers.ripple.com/tef-codes.html
I recommend removing the if('resultCode' in result...) block and check the transaction result. If the transactions failed with tefPAST_SEQ error, my solution to this is set the account sequence in instructions manually or add setTimeOut after each submit.