Develop Reference

Passing in list elements in javascript to a different function

I'm trying to do a web scraping exercise where some values are being retrieved and are being stored in a list variable. I am then passing in the list variable as a parameter in a different function. The problem with my approach is I am getting an error when calling the different function. I believe I'm getting this error because I am not passing in the list elements into the function appropriately. In the function, I am reading from a Yahoo Stock API used to retrieve stock data. If I were to hardcode a stock symbol into the parameter for the function, it works without any issue. Since I am passing in a parameter, I am getting this error. Below is my code and the error I am getting. Any feedback would be helpful.
Code
const cheerio = require('cheerio');
const axios = require('axios');
const yahooStockPrices = require('yahoo-stock-prices');
var stockSymbol = []
async function read_fortune_500() {
try {
const { data } = await axios({ method: "GET", url: "https://en.wikipedia.org/wiki/List_of_S%26P_500_companies", })
const $ = cheerio.load(data)
const elemSelector = '#constituents > tbody > tr > td:nth-child(1)'
$(elemSelector).each((parentIndex, parentElem) => {
let keyIndex = 0
if (parentIndex <= 9){
$(parentElem).children().each((childIndex, childElem) => {
const tdValue = $(childElem).text()
if (tdValue) {
//stockObject[keys[keyIndex]] = tdValue
stockSymbol = tdValue
}
})
console.log(stockSymbol)
}
})
} catch (err) {
console.error(err)
}
return stockSymbol;
}
async function collect_stocks(stockSymbol) {
stockSymbol = read_fortune_500()
const stockResult = await yahooStockPrices.getCurrentData(stockSymbol);
console.log(stockResult);
}
collect_stocks(stockSymbol)
Error
/node_modules/yahoo-stock-prices/yahoo-stock-prices.js:75
.split('regularMarketPrice')[1]
^
TypeError: Cannot read properties of undefined (reading 'split')
at Request._callback (/node_modules/yahoo-stock-prices/yahoo-stock-prices.js:75:21)
at Request.self.callback (/node_modules/request/request.js:185:22)
at Request.emit (node:events:390:28)
at Request.emit (node:domain:475:12)
at Request.<anonymous> (/node_modules/request/request.js:1154:10)
at Request.emit (node:events:390:28)
at Request.emit (node:domain:475:12)
at IncomingMessage.<anonymous> (/node_modules/request/request.js:1076:12)
at Object.onceWrapper (node:events:509:28)
at IncomingMessage.emit (node:events:402:35)

The parameter stockSymbol seems to be empty when you pass it to your desired function therefore, when yahoo-stock-prices try to apply a split on it, it fails.

How to solve сannot read property 'databaseURL' of null in Cloud Functions for Firebase?

I have a table titled 'bestOffers' in Cloud Firestore
I am using a function that calls when a document is added to a table.
The event settings are like this:
Event type: create
The path to the document: bestOffers/{id}
Function:
And when I run the function, I get a cannot read property 'databaseURL' of null error
Can you please tell me what am I doing wrong?
Code:
const functions = require('firebase-functions')
const admin = require('firebase-admin')
admin.initializeApp()
exports.sendNotification = functions.database.ref('bestOffers/{id}').onWrite(async (change, context) => {
})
Tracing:
TypeError: Cannot read property 'databaseURL' of null
at resourceGetter (/workspace/node_modules/firebase-functions/lib/providers/database.js:92:54)
at cloudFunctionNewSignature (/workspace/node_modules/firebase-functions/lib/cloud-functions.js:102:13)
at cloudFunction (/workspace/node_modules/firebase-functions/lib/cloud-functions.js:151:20)
at Promise.resolve.then (/layers/google.nodejs.functions-framework/functions-framework/node_modules/#google-cloud/functions-framework/build/src/invoker.js:198:28)
at process._tickCallback (internal/process/next_tick.js:68:7)

Have a look at the signature of the handler function that is passed to onWrite. It has two parameters: a Change<DataSnapshot> and an EventContext.
You declare your Cloud Function with:
...onWrite(async () => {...});
You should do as follows:
.onWrite(async (change, context) => {
const beforeData = change.before.val(); // data before the write
const afterData = change.after.val(); // data after the write
});
and, then, use the change object to get the data stored at the node that triggered the Cloud Function.

Calling async method from instanced Object gives error: TypeError: Object(...) is not a function

I am currently developing an app for educational purposes and facing a problem that is probably trivial but can't get around and solve it.
So basically I am trying to fetch some data from an external API (using Axios for that). I have divided my code into modules that I am exporting to index.js file and from that, I am instancing new Object and calling my async method getResults() which in return should give me data from API. From that point a get error
TypeError: Object(...) is not a function.
Here is an example code:
Module Search.js:
export default class Search {
constructor(query, num) {
this.query = query;
this.num = num;
}
async getResults() {
const url = 'API_URL';
const key = 'API_KEY';
try {
const res = await axios(`${url}?query=${this.query}&number=${this.num}&apiKey=${key}`);
this.result = res.data.results;
console.log(this.result);
} catch (error) {
console.log(error);
}
}
}
And here is index.js file:
import Search from "./models/Search";
const s = new Search('cheese', 2);
s.getResults()
And finally error in console:
TypeError: Object(...) is not a function
at Search._callee$ (Search.js:42)
at tryCatch (runtime.js:65)
at Generator.invoke [as _invoke] (runtime.js:303)
at Generator.prototype.<computed> [as next] (runtime.js:117)
at asyncGeneratorStep (Search.js:5)
at _next (Search.js:7)
at eval (Search.js:7)
at new Promise (<anonymous>)
at Search.eval (Search.js:7)
at Search.getResults (Search.js:65)
I am probably doing something wrong here, any help and insight would be appreciated. Thanks.

await axios(`${url}?query=${this.query}&number=${this.num}&apiKey=${key}`);
This is the line creating error,
axios is an object which you are trying to use as function
You probably wish to use get/post method provided by axios to call your endpoint
await axios.get(`${url}?query=${this.query}&number=${this.num}&apiKey=${key}`);
You can have a look how you want to use axios https://github.com/axios/axios

Cloud Firestore: TypeError: Cannot read property 'ref' of undefined

Cloud Firestore: TypeError: Cannot read property 'ref' of undefined
I'm using Cloud Functions to update the comments number in the parent collection of Cloud Firestore, so when a comment added the Cloud Functions can automatically update the comment number.
exports.updateCommentNumbers = functions.firestore
.document('postlist/{postlistId}/comments/{commentsID}')
.onCreate(event =>
{
const collectionRef = event.after.ref.parent;
const countRef = collectionRef.parent.child('comment_number');
//const previousValue = event.data.previous.data();
let increment;
if (event.after.exists() )
{
increment = 1;
}
else
{
return null;
}
return countRef.transaction((current) =>
{
return (current || 0) + increment;
}).then(() =>
{
return console.log('Comments numbers updated.');
});
});
I got error which I don't understand. Could you tell me what's wrong?
TypeError: Cannot read property 'ref' of undefined
at exports.updateCommentNumbers.functions.firestore.document.onCreate.event
(/user_code/index.js:46:35)
at Object. (/user_code/node_modules/firebase-functions/lib/cloud-functions.js:112:27)
at next (native)
at /user_code/node_modules/firebase-functions/lib/cloud-functions.js:28:71
at __awaiter (/user_code/node_modules/firebase-functions/lib/cloud-functions.js:24:12)
at cloudFunction (/user_code/node_modules/firebase-functions/lib/cloud-functions.js:82:36)
at /var/tmp/worker/worker.js:716:24
at process._tickDomainCallback (internal/process/next_tick.js:135:7)

As show in this upgrade guide the signature of Cloud Functions for Firebase has changes when it switched to v1.0.
If you used this before v1.0:
exports.dbWrite = functions.firestore.document('/path').onWrite((event) => {
const beforeData = event.data.previous.data(); // data before the write
const afterData = event.data.data(); // data after the write
});
It now is:
exports.dbWrite = functions.firestore.document('/path').onWrite((change, context) => {
const beforeData = change.before.data(); // data before the write
const afterData = change.after.data(); // data after the write
});
Instead of rewriting the code for you, I recommend you update it based on that documentation, or check where you got the code from to see if there's an updated version.

Cloud Messaging in Cloud Functions: admin.messagin(...).send is not a function

My function is triggered by a database event and uses Firebase Cloud Messaging to send a notification to a topic. My first function works fine, but the second one keeps throwing this error:
2018-02-20T21:16:49.878Z E receiveMessage: TypeError: admin.messaging(...).send is not a function
at exports.receiveMessage.functions.database.ref.onCreate (/user_code/index.js:55:27)
at Object.<anonymous> (/user_code/node_modules/firebase-functions/lib/cloud-functions.js:59:27)
at next (native)
at /user_code/node_modules/firebase-functions/lib/cloud-functions.js:28:71
at __awaiter (/user_code/node_modules/firebase-functions/lib/cloud-functions.js:24:12)
at cloudFunction (/user_code/node_modules/firebase-functions/lib/cloud-functions.js:53:36)
at /var/tmp/worker/worker.js:695:26
at process._tickDomainCallback (internal/process/next_tick.js:135:7)
here is the index.js file:
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
// // Create and Deploy Your First Cloud Functions
// // https://firebase.google.com/docs/functions/write-firebase-functions
//
// exports.helloWorld = functions.https.onRequest((request, response) => {
// response.send("Hello from Firebase!");
// });
exports.recceiveInvitation = /* the function that works */;
exports.receiveMessage = functions.database.ref('/messages/{chatId}/{time}').onCreate((event) => {
const chatId = event.params.chatId;
console.log('messages', chatId);
var sender = event.data.val().name;
var messageContent = event.data.val().message;
if(messageContent.length >= 100){
messageContent = messageContent.substring(0,97)+"...";
}
const payload = {
data: {
title: `New Message from ${sender}`,
body: messageContent
},
topic: chatId
};
return admin.messaging().send(payload);
});
I ran npm install firebase-admin, but I did not help.

change this:
return admin.messaging().send(payload);
to this:
return admin.messaging().sendToTopic(topicname,payload);
to be able to send notifications to topics.
You can do the above, or check the note below
Note:
You need to update the firebase-admin npm package, to be able to use send():
npm install firebase-admin#latest
more info here:-
https://firebase.google.com/support/release-notes/admin/node
https://firebase.google.com/docs/cloud-messaging/admin/send-messages

let message = {notification: {title: "your title",body: "your message",},token:"token of user device"
};
admin.messaging().send(message)