Develop Reference

Trying to send params to axios in get - react

I'm new here on the site, and new to React.
I built a function that works great in nodejs. There are rare cases where I want to run this function according to the parameters I send it to, so I try to send it the parameters but I think I can not, I try to print it - and I do not get a print of the parameters I want to send.
i run the function throw click at buttom in react:
<Button onClick={() => {
const result = [1,2,3,4,5,"test"];
props.makeMatchVer2(result);
}}>
make match ver2
</Button>
the action I'm run in axios:
export const makeMatchVer2 = (data) => (dispatch) => {
dispatch({ type: LOADING_DATA });
axios
.get('/kmeans', {
params: {
filterArray: data
}
})
.then((res) => {
dispatch({
type: MAKE_MATCH,
payload: res.data
});
})
.catch((err) => {
dispatch({
type: MAKE_MATCH,
payload: []
});
});
};
the function I'm build in nodeJS:
exports.addUserKmeansMatch = (req, res) => {
console.log("addUserKmeansMatch function start:");
console.log(req.data);
if(req.params)
{
console.log(req.params);
}
let userIndex = 0;
let engineers = [];
let engineersHandles = [];
let engineerDetailsNumeric = {};
db.collection("preferences").get().then(querySnapshot => {
querySnapshot.forEach(doc => {
const engineerDetails = doc.data();
if (engineerDetails.handle === req.user.handle) {
engineersHandles.unshift(engineerDetails.handle);
delete engineerDetails.handle;
engineerDetailsNumeric = convertObjectWithStrToNumber(engineerDetails);
engineers.unshift(engineerDetailsNumeric);
}
else {
engineersHandles.push(engineerDetails.handle);
delete engineerDetails.handle;
engineerDetailsNumeric = convertObjectWithStrToNumber(engineerDetails);
engineers.push(engineerDetailsNumeric);
}
});
kmeans.clusterize(engineers, { k: 4, maxIterations: 5, debug: true }, (err, result) => {
if (err) {
console.error(err);
return res.status(500).json({ error: err.code });
} else {
const cluster = result.clusters;
let foundedMatches = GetUserSerialGroup(userIndex, [...cluster], [...engineers]);
let foundedMatchesHandle = GetUserSerialGroupHandle(userIndex, [...cluster], [...engineersHandles]);
let totalTest = {
foundedMatches: foundedMatches,
foundedMatchesHandle: foundedMatchesHandle,
cluster: cluster,
engineersHandles: engineersHandles,
engineers: engineers
};
let userMatchHandle = reduceUserMatchHandle(foundedMatchesHandle);
userMatchHandle.handle = req.user.handle;
db.doc(`/match/${req.user.handle}`)
.set(userMatchHandle)
.then(() => {
return res.json({ message: "Details added successfully" });
})
.catch((err) => {
console.error(err);
return res.status(500).json({ error: err.code });
});
}
})
})
};
Through the button, I send parameters to the function, but I do not see their print, probably something does not work, but I do not know why, I'm new to it

makeMatchVer2 is a thunk. You should call it with dispatch: dispatch(props.makeMatchVer2(result))

The code is correct, I accidentally sent the wrong object, I have 2 objects with almost identical names, one array and the other an object. And I accidentally sent the object instead of the array, it's working right now, thank you.

How to use promise and loop over mongoose collection

I'm making chat inside my website. To store data I use Chat, User, Messages collections.
I want results to be in Array containing:
[{
username (another one, not me)
last update
last message
}]
In Chat model I have only chatid and array of two members, so I need to loop through User collection to get user name using user id from it. I want to save in array all names (in future I would also like to loop through messages to get latest messages for each chatid). Issue is that when I return chatsList it is empty. I think I need somehow to use Promise, but I'm not completely sure how it should work.
Chat.find({ members: userId })
.then(chats => {
let chatsList = [];
chats.forEach((chat, i) => {
let guestId = chat.members[1 - chat.members.indexOf(userId)];
User.findOne({ _id: guestId })
.then(guest => {
let chatObj = {};
name = guest.name;
chatsList.push(name);
console.log("chatsList", chatsList)
})
.catch(err => console.log("guest err =>", err))
})
return res.json(chatsList)
})
.catch(err => {
errors.books = "There are no chats for this user";
res.status(400).json(errors);
})

Indeed, Promise.all is what you are looking for:
Chat.find({ members: userId })
.then(chats => {
let userPromises = [];
chats.forEach((chat, i) => {
let guestId = chat.members[1 - chat.members.indexOf(userId)];
userPromises.push(User.findOne({ _id: guestId }));
});
return Promise.all(userPromises).then(guests => {
let chatsList = [];
guests.forEach(guest => {
chatsList.push(guest.name);
});
return res.json(chatsList);
});
});
});
although it would probably be better to do a single call to DB with a list of ids ($in query). Something like this:
Chat.find({ members: userId })
.then(chats => {
let ids = [];
chats.forEach((chat, i) => {
let guestId = chat.members[1 - chat.members.indexOf(userId)];
ids.push(guestId);
});
return User.find({_id: {$in: ids}}).then(guests => {
let chatsList = [];
guests.forEach(guest => {
chatsList.push(guest.name);
});
return res.json(chatsList);
});
});
});
You may want to additionally validate if every id had a corresponding guest.

You are running into concurrency issues. For example, running chats.forEach, and inside forEach running User.findOne().then: The return statement is already executed before the User.findOne() promise has resolved. That's why your list is empty.
You could get more readable and working code by using async/await:
async function getChatList() {
const chats = await Chat.find({members: userId});
const chatsList = [];
for (const chat of chats) {
let guestId = chat.members[1 - chat.members.indexOf(userId)];
const guest = await User.findOne({_id: guestId});
chatsList.push(guest.name);
}
return chatsList;
}
Then the code to actually send the chat list back to the user:
try {
return res.json(await getChatList());
} catch (err) {
// handle errors;
}

You can try this:
Chat.find({ members: userId }).then(chats => {
let guestHashMap = {};
chats.forEach(chat => {
let guestId = chat.members.filter(id => id != userId)[0];
// depending on if your ID is of type ObjectId('asdada')
// change it to guestHashMap[guestId.toString()] = true;
guestHashMap[guestId] = true;
})
return Promise.all(
// it is going to return unique guests
Object.keys(guestHashMap)
.map(guestId => {
// depending on if your ID is of type ObjectId('asdada')
// change it to User.findOne({ _id: guestHashMap[guestId] })
return User.findOne({ _id: guestId })
}))
})
.then(chats => {
console.log(chats.map(chat => chat.name))
res.json(chats.map(chat => chat.name))
})
.catch(err => {
errors.books = "There are no chats for this user";
res.status(400).json(errors);
})

Firestore simple leaderboard function

I'm tring to write a cloud function that ranks my users under the /mobile_user node by earned_points and assigns them a rank. I have successfully done this but now i want to write those same 10 users to another node called leaderboard. How can i accomplish this?
Here is my current function which already ranks them from 1 to 10:
exports.leaderboardUpdate2 = functions.https.onRequest((req, res) =>{
const updates = [];
const leaderboard = {};
const rankref = admin.firestore().collection('mobile_user');
const leaderboardRef = admin.firestore().collection('leaderboard');
return rankref.orderBy("earned_points").limit(10).get().then(function(top10) {
let i = 0;
console.log(top10)
top10.forEach(function(childSnapshot) {
const r = top10.size - i;
console.log(childSnapshot)
updates.push(childSnapshot.ref.update({rank: r}));
leaderboard[childSnapshot.key] = Object.assign(childSnapshot, {rank: r});
i++;
console.log(leaderboard)
});
updates.push(leaderboardRef.add(leaderboard));
return Promise.all(updates);
}).then(() => {
res.status(200).send("Mobile user ranks updated");
}).catch((err) => {
console.error(err);
res.status(500).send("Error updating ranks.");
});
});
This successfully updates the /mobile_user node where all my users are but i want to "export" those 10 users to the leaderboard node once the function executes.
(Note that the leaderboard node should have only 10 records at all times)

There are two problems in your Cloud Function:
Firstly you cannot directly use the childSnapshot object (neither with Object.assign nor directly) to create a new document. You have to use childSnapshot.data(), see https://firebase.google.com/docs/reference/js/firebase.firestore.DocumentSnapshot
Secondly, you use childSnapshot.key while it should be childSnapshot.id, see the same document than above.
Finally, note that, with your code structure, the users document are added as maps under a unique leaderboard document. I am not sure it is exactly what you want, so you may adapt your code for this specific point.
So the following should work:
exports.leaderboardUpdate2 = functions.https.onRequest((req, res) => {
const updates = [];
const leaderboard = {};
const rankref = admin.firestore().collection('mobile_user');
const leaderboardRef = admin.firestore().collection('leaderboard');
return rankref
.orderBy('earned_points')
.limit(10)
.get()
.then(function(top10) {
let i = 0;
console.log(top10);
top10.forEach(function(childSnapshot) {
const r = top10.size - i;
updates.push(childSnapshot.ref.update({ rank: r }));
leaderboard[childSnapshot.id] = Object.assign(childSnapshot.data(), {
rank: r
});
i++;
});
updates.push(leaderboardRef.add(leaderboard));
return Promise.all(updates);
})
.then(() => {
res.status(200).send('Mobile user ranks updated');
})
.catch(err => {
console.error(err);
res.status(500).send('Error updating ranks.');
});
});
Following your comment, here is a new version, that writes a doc, in the leaderboard Collection, for each mobile_user. Note that we use a DocumentReference and together with the set() method, as follows: leaderboardRef.doc(childSnapshot.id).set()
exports.leaderboardUpdate2 = functions.https.onRequest((req, res) => {
const updates = [];
const leaderboard = {};
const rankref = admin.firestore().collection('mobile_user');
const leaderboardRef = admin.firestore().collection('leaderboard');
return rankref
.orderBy('earned_points')
.limit(10)
.get()
.then(function(top10) {
let i = 0;
console.log(top10);
top10.forEach(function(childSnapshot) {
const r = top10.size - i;
updates.push(childSnapshot.ref.update({ rank: r }));
updates.push(
leaderboardRef.doc(childSnapshot.id).set(
Object.assign(childSnapshot.data(), {
rank: r
})
)
);
i++;
});
return Promise.all(updates);
})
.then(() => {
res.status(200).send('Mobile user ranks updated');
})
.catch(err => {
console.error(err);
res.status(500).send('Error updating ranks.');
});
});

Node js - function to return array of objects read from sequelize database

I'm trying to create a function in node js which reads database values in and pushes them into an array, and then at the end returns this array. My functions looks like this at the moment:
function getInvoicesCount() {
let promiseInvoices = [];
let userInvCount = 0;
let deletedUserInvCount = 0;
let userInvAmount = 0;
let deletedUserInvAmount = 0;
let monthWiseInvCount = [];
db.userInvoices
.findAll({
attributes: [
'deleted_at',
[sequelize.fn('COUNT', sequelize.col('id')), 'count'],
[sequelize.fn('SUM', sequelize.col('invoice_amount')), 'amount'],
[sequelize.fn('MONTH', sequelize.col('invoice_date')), 'month']
],
group: ['invoice_date', 'deleted_at'],
paranoid: false
})
.then(result => {
result.forEach(function(element) {
userInvCount += element.dataValues.count;
userInvAmount += element.dataValues.amount;
if (element.dataValues.deleted_at != null) {
deletedUserInvAmount += element.dataValues.amount;
deletedUserInvCount += element.dataValues.count;
}
monthWiseInvCount.push(element.dataValues);
});
if (monthWiseInvCount.map(a => a === 'deleted_at')) {
monthWiseInvCount.map(a => delete a.deleted_at);
}
promiseInvoices.push(
userInvCount,
userInvAmount,
deletedUserInvCount,
deletedUserInvAmount,
monthWiseInvCount
);
});
return promiseInvoices;
}
In the main part of the code I would like to call this funtion and use a .then to get the returned array
Can you help me out how I can return a promise in the function and how will the array be accessible in the .then part?

Here are the changes you need to do to get expected result :
function getInvoicesCount() {
...
return db.userInvoices.findAll({ //<-------- 1. First add return here
...
}).then(result => {
...
return promiseInvoices; //<----------- 2. Put this line inside the then
});
// return promiseInvoices; //<----------- Remove this line from here
}
getInvoicesCount().then(data => {
console.log(data); // <------- Check the output here
})
Explanation for this :
To get .then when you can function , function should return promise ,
but in you case you are just returning a blank array ,
As per the sequlize doc , db.userInvoices.findAll returns the
promise so all you need to do is add return before the this function
, First step is done
You were return promiseInvoices; at wrong place , why ? , coz at
that you will never get the result , as the code above it run in async
manner as it is promise , so you will always get the balnk array , to
get the expected result you should return it from
db.userInvoices.findAll's then function as shown above in code

You should return the results from then to access it in the chain.
function getInvoicesCount() {
const promiseInvoices = []
let userInvCount = 0
let deletedUserInvCount = 0
let userInvAmount = 0
let deletedUserInvAmount = 0
const monthWiseInvCount = []
return db.userInvoices
.findAll({
attributes: [
'deleted_at',
[sequelize.fn('COUNT', sequelize.col('id')), 'count'],
[sequelize.fn('SUM', sequelize.col('invoice_amount')), 'amount'],
[sequelize.fn('MONTH', sequelize.col('invoice_date')), 'month'],
],
group: ['invoice_date', 'deleted_at'],
paranoid: false,
})
.then((result) => {
result.forEach((element) => {
userInvCount += element.dataValues.count
userInvAmount += element.dataValues.amount
if (element.dataValues.deleted_at != null) {
deletedUserInvAmount += element.dataValues.amount
deletedUserInvCount += element.dataValues.count
}
monthWiseInvCount.push(element.dataValues)
})
if (monthWiseInvCount.map(a => a === 'deleted_at')) {
monthWiseInvCount.map(a => delete a.deleted_at)
}
return promiseInvoices.push(
userInvCount,
userInvAmount,
deletedUserInvCount,
deletedUserInvAmount,
monthWiseInvCount,
)
})
}
You can now use
getInvoicesCount().then(() => {
//do something here
})

getData(htmlData,tags)
.then(function(data) {
console.log(data); //use data after async call finished
})
.catch(function(e) {
console.log(e);
});
function getData() {
return new Promise(function(resolve, reject) {
//call async task and pass the response
resolve(resp);
});
}

In general you can return a promise like this:
function returnPromise() {
return new Promise((resolve, reject) => {
resolve({foo: 'bar'});
});
}
So while the other answer is completely correct, you can use the above structure to create a function that returns a promise like this:
function getInvoicesCount() {
return new Promise((resolve, reject) => {
let promiseInvoices = [];
let userInvCount = 0;
let deletedUserInvCount = 0;
let userInvAmount = 0;
let deletedUserInvAmount = 0;
let monthWiseInvCount = [];
db.userInvoices
.findAll({
attributes: [
'deleted_at',
[sequelize.fn('COUNT', sequelize.col('id')), 'count'],
[sequelize.fn('SUM', sequelize.col('invoice_amount')), 'amount'],
[sequelize.fn('MONTH', sequelize.col('invoice_date')), 'month']
],
group: ['invoice_date', 'deleted_at'],
paranoid: false
})
.then(result => {
result.forEach(function(element) {
userInvCount += element.dataValues.count;
userInvAmount += element.dataValues.amount;
if (element.dataValues.deleted_at != null) {
deletedUserInvAmount += element.dataValues.amount;
deletedUserInvCount += element.dataValues.count;
}
monthWiseInvCount.push(element.dataValues);
});
if (monthWiseInvCount.map(a => a === 'deleted_at')) {
monthWiseInvCount.map(a => delete a.deleted_at);
}
promiseInvoices.push(
userInvCount,
userInvAmount,
deletedUserInvCount,
deletedUserInvAmount,
monthWiseInvCount
);
resolve(promiseInvoices); // When you are done, you resolve
})
.catch(err => reject(err)); // If you hit an error - reject
});
}
However that is a rather big function, would recommend splitting it up in smaller parts.

Web scraping and promises

I am using cheerio and node to do web scraping, but I have a problem with promises. I can scrape an article list from a page but in that list, we have more links for single pages. I need to scrape single pages as well for each item on the list.
I will show you my code for the better solution.
import rp from 'request-promise'
import cheerio from 'cheerio'
import conn from './connection'
const flexJob = `https://www.flexjobs.com`
const flexJobCategory = ['account-management', 'bilingual']
class WebScraping {
//list of article e.g for page 2
results = [] // [[title], [link for page],...]
contentPage = [] //content for each page
scrapeWeb(link) {
let fullLink = `${link}/jobs/${flexJobCategory[1]}?page=2`
const options = {
uri: fullLink,
transform(body) {
return cheerio.load(body)
}
}
rp(options)
.then(($) => {
console.log(fullLink)
$('.featured-job').each((index, value) => {
//html nodes
let shortDescription = value.children[1].children[1].children[3].children[1].children[1].children[0].data
let link = value.children[1].children[1].children[1].children[1].children[1].children[0].attribs.href
let pageLink = flexJob + '' + link
let title = value.children[1].children[1].children[1].children[1].children[1].children[0].children[0].data
let place = value.children[1].children[1].children[1].children[1].children[3].children[1].data
let jobType = value.children[1].children[1].children[1].children[1].children[3].children[0].children[0].data
this.results.push([title, '', pageLink.replace(/\s/g, ''), '', shortDescription.replace(/\n/g, ''), place, jobType, 'PageContent::: '])
})
})
.then(() => {
this.results.forEach(element => {
console.log('link: ', element[2])
this.scrapePage(element[2])
});
})
.then(() => {
console.log('print content page', this.contentPage)
})
.then(() => {
//this.insertIntoDB()
console.log('insert into db')
})
.catch((err) => {
console.log(err)
})
}
/**
* It's going to scrape all pages from list of jobs
* #param {Any} pageLink
* #param {Number} count
*/
scrapePage(pageLink) {
let $this = this
//console.log('We are in ScrapePage' + pageLink + ': number' + count)
//this.results[count].push('Hello' + count)
let content = ''
const options = {
uri: pageLink,
transform(body) {
return cheerio.load(body)
}
}
rp(options)
.then(($) => {
//this.contentPage.push('Hello' + ' : ');
console.log('Heloo')
})
.catch((err) => {
console.log(err)
})
}
/**
* This method is going to insert data into Database
*/
insertIntoDB() {
conn.connect((err) => {
var sql = "INSERT INTO contact (title, department, link, salary, short_description, location, job_type, page_detail) VALUES ?"
var values = this.results
conn.query(sql, [values], function (err) {
if (err) throw err
conn.end()
})
})
}
}
let webScraping = new WebScraping()
let scrapeList = webScraping.scrapeWeb(flexJob)
So, at 'scrapeWeb' method, at second '.then', I am calling 'scrapePage' method, however, the third promise executed before promise inside 'scrapePage' method.

You need a little more control flow at that stage. You do not want that .then()'s promise to resolve until all the calls are resolved.
You could use a Promise library like bluebird to do a Promise.each or a Promise.map for all the results you want to run.
Or use async/await to set up like .then(async () => {}) and do not use .forEach.
for(let element of this.results){
console.log('link: ', element[2])
await this.scrapePage(element[2])
}

You have a race condition problem.
The first tweak you'll need is having scrapePage returning a Promise.
scrapePage(pageLink) {
let $this = this
let content = ''
const options = {
uri: pageLink,
transform(body) {
return cheerio.load(body)
}
}
return rp(options);
}
In the second than, you need to invoke all child pages scraping eg :
.then(() => {
return Promise.all(this.results.map(childPage => this.scrapePage(childPage)));
})
This will wrap all scrapes of child pages into promises and only if all of them are resolved the code will flow.