We Keep Coding

How to get child Snapshots inside snapshots on Google Cloud functions (Firebase)?

I'm trying to get some for Loops running inside a google cloud functions everytime I delete my /users node.
This is the code I'm using
exports.deleteUserAssets = functions.database.ref('/users/{userId}').onWrite((change, context) => {
const beforeData = change.before.val();
const afterData = change.after.val();
const userBuildings = Object.keys(beforeData.isAdmin); // get the buildings of the user stored in the user/userId/isAdmin node .. so far so good
const userId = beforeData.userIDforCloudFunctions; // I'm getting this from a /users/userid/userIDforCloudFucntions node ...so far so good (i've been logging it to confirm)
// making sure it was a delete operation ... so far so good
if (afterData !== null) {
return 0;
}
else {
// on each building
for (var i = 0; i < userBuildings.length; i++) {
let eachBuilding = [userBuildings[i]]
// HERE IS WERE THE PROBLEM IS: Trying to delete all depts + rooms + doors
admin.database().ref('/buildings/' + eachBuilding)
.child("hasDepts")
.once("value")
.then(function(snapshot) { // This is where it goes south – snapshot is returning null
snapshot.forEach(function(childSnapshot) {
var deptKeyString = childSnapshot.key; // will try to get the keys of the departments stored under this space
var deptsOnNode = admin.database().ref('/depts/' + deptKeyString);
deptsOnNode.remove(); // and use the keys to delete each of the depts on depts
});
});
admin.database().ref('/buildings/' + eachBuilding).set({}); // this is working
admin.database().ref('/buildingsUserUid/' + userId + '/' + eachBuilding).remove(); // this is working
}
}
return 0;
});
The snapshot of admin.database().ref('/buildings/' + eachBuilding).child("hasDepts") is returning null.
How can I get to it? Besides admin.database().ref() I've tried to reach it with firebase.database().ref() which is the command/object i use to get this running on frontend functions. I've also tried functions.database() with no result.

Taking in consideration what Doug Stevenson mentioned in his second comment:
exports.deleteUserAssets = functions.database.ref('/users/{userId}').onDelete((change, context, event) => {
const beforeData = change.before.val(); // data before the write (data of all the doors child nodes)
const afterData = change.after.val(); // data before the write (data of all the doors child nodes)
const userBuildings = Object.keys(beforeData.isAdmin); // get the buildings of the user
const userId = beforeData.userIDforCloudFunctions;
// make sure user was deleted
if (afterData !== null) {
return 0;
}
else {
// on each building
for (var i = 0; i < userBuildings.length; i++) {
let eachBuilding = [userBuildings[i]]
// Need to RETURN the whole chain of promises
return admin.database().ref('/buildings/' + eachBuilding)
.child("hasDepts")
.once("value")
.then(function(snapshot) {
console.log(snapshot.val()) // this now works
snapshot.forEach(function(childSnapshot) {
console.log(childSnapshot.val()) // this works as well
var deptKeyString = childSnapshot.key; // get the keys of the departments stored under this space
var deptsOnNode = admin.database().ref('/depts/' + deptKeyString);
// and you can keep on going deeper if you return promises
return deptsOnNode
.child('hasRooms')
.once('value')
.then(function(grandchildSnapshot){
console.log(grandchildSnapshot.val())
grandchildSnapshot.forEach(function(grandGrandchildSnapshot){
var roomKeyString = grandGrandchildSnapshot.key;
var roomsOnDepts = admin.database().ref('/rooms/' + roomKeyString);
admin.database().ref('/roomOwners/' + userId + '/' + roomKeyString).remove();
// and return again here...
return roomsOnDepts
.child('hasDoors')
.once('value')
.then(function(grandgrandGrandchildSnapshot){
grandgrandGrandchildSnapshot.forEach(function(grandgrandGrandchildSnapshot){
var doorKeyString = grandgrandGrandchildSnapshot.key;
var doorsOnRooms = admin.database().ref('/doors/' + doorKeyString);
doorsOnRooms.remove();
let clipOwners = admin.database().ref('/clipOwners/' + doorKeyString);
clipOwners.remove();
})
roomsOnDepts.remove();
})
})
deptsOnNode.remove(); // use the keys to delete the depts on depts main Node
})
});
admin.database().ref('/buildings/' + eachBuilding).set({});
admin.database().ref('/buildingsUserUid/' + userId + '/' + eachBuilding).remove();
});
}
}
return 0;
});

Why Won't This Firebase Callable Function Return A Value?

I have a callable function that should return a value, but the only thing ever returned is null. Below is the current version of the function. I have also tried having a return on the first promise (the original once call), and at the end in another then returning the GUID. It actually returned data in that case, but it returned immediately and the GUID was empty.
How can I accomplish my goal and still return the GUID? I don't know when the function is called if I will use a new GUID that I generate, or one that already exists in the database.
There is a similar question here: Receiving returned data from firebase callable functions , but in that case it was because he never returned a promise from the function. I am returning a promise on all code paths. Unless I have to return the initial promise from the once call? In which case, how can I return the GUID when I don't know it yet?
I am also trying to throw an error in a couple of places and the error shows up in the logs for the function, but is never sent to the client that called the function.
I am going off of the examples here: https://firebase.google.com/docs/functions/callable
Sorry for the code bomb.
Calling the function:
var newGame = firebase.functions().httpsCallable('findCreateGame');
newGame({}).then(function(result) {
// Read result of the Cloud Function.
//var sGameID = result.data.guid;
console.log(result);
}).catch(function(error) {
console.log(error);
});
Function:
exports.findCreateGame = functions.https.onCall((data, context) => {
console.log("findCurrentGame Called.")
/**
* WHAT NEEDS DONE
*
*
* Pull in user's information
* Determine their win/loss ratio and search for a game using transactions in either low medium or high queue
* If there are no open games in their bracket, search the one above, then below
* If no open games anywhere, create a new game in their bracket
* If an open game is found, write the UID to the game and add the game's ID to the user's profile
*
*/
var uid = context.auth.uid;
var section = "";
var sUsername = "";
var sProfilePic = "";
var currentGames = null;
var sGUID = "";
//Get the user's info
var userref = admin.database().ref('users/' + uid);
userref.once("value", function(data) {
var ratio = 0;
var wins = parseInt(data.val().wins);
var losses = parseInt(data.val().losses);
var lives = parseInt(data.val().lives);
if (lives < 1){
//This user is out of lives, should not have been able to get here
//Throw an exception so that we can see why it failed
throw new functions.https.HttpsError('permission-denied', 'You do not have enough lives to start a new game.');
}
sUsername = data.val().username;
sProfilePic = data.val().profilepicture;
//Handle if they have no losses
if (losses == 0){
ratio = 100;
} else {
ratio = (wins / losses) * 100;
}
//If they have played less than 5 games, put them in noob tier
if (wins + losses < 5){
ratio = 0;
}
if (ratio <= 33){
section = "noob";
} else if (ratio > 33 && ratio <= 66){
section = "average";
} else {
section = "expert";
}
}).then(() => {
//Get all of the games this user is currently in
admin.database().ref('games').orderByChild(uid).once('value', function(data) {
currentGames = data.val();
}).then(() => {
//Generate a new GUID in case we need to set up a new game
sGUID = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
var r = Math.random() * 16 | 0, v = c == 'x' ? r : (r & 0x3 | 0x8);
return v.toString(16);
});
var queueref = admin.database().ref('gamequeue/' + section);
queueref.transaction(function(currentGUID) {
if (currentGUID == null){
//Write our GUID in the queue
return sGUID;
} else {
//Get the id of the game we just got
sGUID = currentGUID
return null;
}
}).then((res) => {
if (res.snapshot.val() != null){
//This means we are creating the game lobby
//Generate a new answer
var newAnswer = "";
while (newAnswer.length < 4){
var temp = Math.floor(Math.random() * 9) + 1;
temp = temp.toString();
if (!newAnswer.includes(temp)){
newAnswer += temp;
}
}
var obj = {username: sUsername, score: 0, profilepicture: sProfilePic};
return admin.database().ref('games/' + sGUID).set({id: sGUID, requestor: uid, [uid]: obj, answer: newAnswer, turn: uid, status: 'pending'}).then(() => {
return {guid: sGUID};
});
} else {
//We found a game to join
//If we are in a duplicate request situation, make sure the GUID is a string
if (typeof(sGUID) != 'string'){
sGUID = Object.keys(sGUID)[0];
}
//Make sure we didn't find our own game request
if (currentGames[sGUID] != null){
//Add this GUID back to the queue, we shouldn't have removed it
return admin.database().ref('gamequeue/' + section + '/' + sGUID).set('');
//Throw an exception that says you can only have one open game at a time
throw new functions.https.HttpsError('already-exists', 'We are still finding a match for your last request. You are only allowed one open request at a time.');
} else {
//Get the current game info
admin.database().ref('games/' + sGUID).once('value', function(data) {
var sRequestor = data.val().requestor;
var sOpponentUsername = data.val()[sRequestor].username;
var sOpponentProfilePic = data.val()[sRequestor].profilepicture;
//Write all of our info to the game
return admin.database().ref('games/' + sGUID).update({[sRequestor]: {opponentusername: sUsername, opponentprofilepicture: sProfilePic}, [uid]: {username: sUsername, score: 0, opponentusername: sOpponentUsername, opponentprofilepicture: sOpponentProfilePic}, status: 'active'}).then(() => {
return {guid: sGUID};
});
});
}
}
});
});
})
});

The documentation for callable functions explains:
To return data after an asynchronous operation, return a promise. The
data returned by the promise is sent back to the client.
You have many asynchronous operations that must be chained together. A return needs to be added to each of these statements (as shown):
return userref.once("value", function(data) {...
return admin.database().ref('games').orderByChild(uid).once('value', function(data) {...
return queueref.transaction(function(currentGUID) {...
return admin.database().ref('games/' + sGUID).once('value', function(data) {...

Node / MySQL - code: 'ER_PARSE_ERROR', when trying to insert ~800 records

I am working on small idea to collect errors from pages and to store them in DB and then use graph API to display information visually.
There is 8 sites and on each of them there is 100 entries - so 800 transactions per time.
I loop through each site and then sub-loop through table of errors and collect them.
I got it working if I make insert query on each of those sub-loops for all 800 entries but I am getting some sort of memory leak from so many transactions and after few minutes - Node breaks due to memory exceeding.
So I tried queuing all 800 entries into Array of Arrays and then performing multi-insert at the end of every iteration but I am getting ER_PARSE_ERROR.
var tabletojson = require('tabletojson');
var mysql = require("mysql");
var striptag = require("striptags");
var fs = require("fs");
var path = require('path');
var startCollector;
var iterations = 0;
var insertions = 0;
var duplicated = 0;
var datas = [];
var clients = ["ClientA", "ClientB", "ClientC", "ClientD", "ClientE", "ClientF", "ClientG", "ClientH"];
var appDir = path.dirname(require.main.filename);
var errorList = ["err1", "err2", "err3", "err4", "err5", "err6"];
var con = mysql.createPool({
host: "localhost",
user: "User",
password: "Password",
database: "errors"
});
function CollectErrors() {
startCollector = new Date();
for(var a = 0; a < clients.length; a++) {
(function(a) {
tabletojson.convertUrl("http://example.com" + clients[a] + "/page.php?limit=100", { stripHtmlFromCells: false }, function(response) {
var rs = response[0];
for(var l = rs.length-1; l > -1; l--) {
var newDate = formatDate(striptag(rs[l]["Date"]), striptag(rs[l]["Time"]));
var user = getUser(striptag(rs[l]["User"]));
var msg = striptag(rs[l]["Error"]);
var splitError = rs[l]["Error"].split("<a href=\"");
var link = getUrl(splitError[1]);
var id = getId(link);
var type = getType(striptag(splitError[0]));
var temp = [newDate, link, type, user, clients[a], id, msg];
datas.push(temp);
}
});
})(a);
}
con.getConnection(function(err, connection) {
connection.query("INSERT IGNORE INTO entries (time, url, type, author, client, uid, message) VALUES ?", [datas], function(err, rows) {
console.log(err);
});
connection.release();
datas = [];
});
setTimeout(CollectErrors, 10000);
}
function formatDate(date, time) {
var newdate = date.split("/").reverse().join("-");
var newtime = time+":00";
return newdate + " " + newtime;
}
function getUrl(uri) {
return "http://example.com/"+uri.split("\">Details")[0];
}
function getId(url) {
return decodeURIComponent((new RegExp('[?|&]' + "id" + '=' + '([^&;]+?)(&|#|;|$)').exec(url) || [null, ''])[1].replace(/\+/g, '%20')) || null;
}
function getType(error) {
for(var a = 0; a < errorList.length; a++) {
if(error.indexOf(errorList[a]) !== -1) {
return errorList[a];
}
}
return "Other";
}
function getUser(user) {
if(user == "" || user == " " || user == null) {
return "System";
}
return user;
}
CollectErrors();
I've tried mysql.createConnection too but that also gave me same issue.
I've been stuck for past 12 hours and I can't see what's wrong, I've even tried populating Datas table with just strings but got same error.

I've changed your code to use ES6 and correct modules features.
Useful links: correct pooling with mysql, correct insert query, async/await, IIFE, enhanced object
const tabletojson = require('tabletojson'),
mysql = require("mysql"),
striptag = require("striptags"),
fs = require("fs"),
path = require('path');
const startCollector,
iterations = 0,
insertions = 0,
duplicated = 0;
let datas = [];
const clients = ["ClientA", "ClientB", "ClientC", "ClientD", "ClientE", "ClientF", "ClientG", "ClientH"];
const appDir = path.dirname(require.main.filename);
const errorList = ["err1", "err2", "err3", "err4", "err5", "err6"];
const con = mysql.createPool({
host: "localhost",
user: "User",
password: "Password",
database: "errors"
});
// We'll use async/await from ES6
const collectErrors = async() => {
// Up to here I've only changed syntax to ES6
let startCollector = new Date();
// We'll try to iterate through each client. And we use here for..of syntax to allow us using await
for (let client of clients) {
// Please, check that client value return correct data. If not, change for..of to your for..each and client variable to clients[a]
const tbj = await tabletojson.convertUrl("http://example.com" + client + "/page.php?limit=100", {
stripHtmlFromCells: false
});
const result = tgj[0];
for (rs of result) {
// I can't check this part, but I hope your example was with correct values.
let newDate = formatDate(striptag(rs[l]["Date"]), striptag(rs[l]["Time"]));
let user = getUser(striptag(rs[l]["User"]));
let link = getUrl(splitError[1]);
let msg = striptag(rs[l]["Error"]);
let id = getId(link);
let splitError = rs[l]["Error"].split("<a href=\"");
let getType = getType(striptag(splitError[0]));
// ES6 enhanced object syntax
datas.push({
newDate,
user,
msg,
id,
splitError,
link,
getType,
temp: [newDate, link, type, user, client, id, msg]
});
}
}
// OK, here we have fulfilled datas array. And we want to save it.
con.getConnection((err, connection) => {
// Please, notice, here I've changed your insert query to prepared statement.
connection.query("INSERT IGNORE INTO entries SET ?", datas, (err, rows) => {
console.log(err);
connection.release();
datas = [];
});
});
// I don't see why do you need timeout here, so I've left it commented.
// setTimeout(CollectErrors, 10000);
};
// Here your other methods go....
// And to call your async function we'll use IIFE
(async() => {
await collectErrors();
})();
Probably there may be errors with mysql insert, but that's not for sure. If occurred, please write in comments and I'll help you with that.

LearnYouNode: Juggling Async without BL/Async/After

I was following this tutorial when a wild step 9 appears.
This problem is the same as the previous problem (HTTP COLLECT) in that you need to use http.get(). However, this time you will be provided with three URLs as the first three command-line arguments.
You must collect the complete content provided to you by each of the URLs and print it to the console (stdout). You don't need to print out the length, just the data as a String; one line per URL. The catch is that you must print them out in the same order as the URLs are provided to you as command-line arguments.
My code was (It doesn't work fine just when he pleases):
http = require("http");
var url = [process.argv[2], process.argv[3], process.argv[4]];
var responses = [];
var completed_responses = 0;
for(var i in url){
http.get(url[i], function(response){
var content = "";
//if(completed_responses == url.length){
response.setEncoding("utf-8");
response.on("data", function(data){
content += data;
})
response.on("error", console.error);
response.on("end", function(end){
console.log(content);
});
})
}
And the answer was:
var http = require("http");
var bl = require("bl");
var results = [];
var count = 0;
function printResults(){
for(var i = 0; i < 3; i++)
console.log(results[i]);
}
function httpGet(index){
http.get(process.argv[2 + index], function(response){
response.pipe(bl(function(err, data){
if (err)
return console.error(err);
results[index] = data.toString();
count++;
if(count == 3)
printResults()
}))
})
}
for(var i = 0; i < 3; i++)
httpGet(i);
What is the right answer WITHOUT BL/AFTER/ETC?
Thanks to all!

I've done that tutorial myself when I was first learning node and I remember that step of the tutorial. The solution was fairly underwhelming. Anyway, for your answer:
NodeJs Asynchronous programming - Coordinating parallel calls
You can check the code in the question and make the fixes I suggested in my answer. That should solve it without BL/Async/Whatever else that tutorial mentions.

Here is my code for the Juggling Async challenge without using any third-party libraries.
var http = require("http");
var urls = [process.argv[2], process.argv[3], process.argv[4]];
var urlResults = new Array("", "", "");
var allDoneCount = 0;
urls.forEach(function (_url) {
http.get(_url, function (resp) {
resp.on("data", function (data) {
if (_url === urls[0]) {
urlResults[0] += data.toString();
} else if (_url === urls[1]) {
urlResults[1] += data.toString();
} else {
urlResults[2] += data.toString();
}
})
resp.on("end", function () {
allDoneCount++;
if (allDoneCount === 3) {
console.log(urlResults[0]);
console.log(urlResults[1]);
console.log(urlResults[2]);
}
})
resp.on("error", function (err) {
console.log(err);
})
}).on("error", function (err) {
console.log(err);
})
})

This is how you can do it without any external modules(except http ;P).
const http = require('http'); //http module
let results = ["", "", ""]; //this will store the data from http.get()
let counter = 0; //to keep a counter for no of httpget's done
//it will iterate when counter is 3 i.e. the 'end' for all
function print() {
for (let i = 0; i < 3; i++) {
console.log(results[i]);
}
}
//accept index(for process.argv) as parameter
function httpGetter(i) {
//http.get method on the url first encountered, 2+i because 2 values are reserved
http.get(process.argv[2 + i], (res) => {
//for converting (res)ponse to string/alternatively toString() method can be used
res.setEncoding('utf8');
//event data on the url, callback with recived chunk as parameter
res.on('data', function(chunk) {
//appending the recived chunk to that element of results corresponding to 'i' of httpGetter function
results[i] += chunk;
});
//event end, when no more data is read
//runs every time for each value of 'i' that is for each url
res.on('end', function() {
//to keep count
counter++;
//when 3 that is when data from all inputs receved
if (counter === 3) {
//print function simply iterating over results array
print();
}
});
})
}
//inputs are recieved from here
for (let i = 0; i < 3; i++) {
//i can be index for results
httpGetter(i);
}

Cannot read 'xyxyx' property of undefined even if element exist

I have two HTML inputs (type="email", type="number") and my Angular app watches them using $formatters and $parsers. The errors are stored in an array and when user insert an email which contains "#gmail" the error is removed from the array.
app.controller('form1Controller', function($scope, UserService) {
$scope.formCompleted = false;
$scope.errors = UserService.errors;
//handle the user email input.
$scope.storeEmailErr = function(data) {
var correctKey = "#gmail";
var key = "#userEmail";
var res = {};
if (data != null) {
res = $scope.handleError(data, emailIn, correctKey, key, $scope.errors);
$scope.errors = res[0];
UserService.errors = res[0];
emailIn = res[1];
}
};
//handle the user email input.
$scope.storeIdErr = function(data) {
var correctKey = "0000";
var key = "#userId";
var res = {};
if (data != null) {
res = $scope.handleError(data, idIn, correctKey, key, $scope.errors);
$scope.errors = res[0];
idIn = res[1];
}
};
}
This is the code that adds and removes errors from array. And here i suppose is the problem
function theIndexOf(val) {
console.log("find index in array of length: " + errorsDescription.length)
for (var i = 0; i < errorsDescription.length; i++) {
if (errorsDescription[i].selector === val) {
return i;
}
}
}
app.run(function($rootScope){
$rootScope.handleError = function(data, elemIn, correctKey, key, errorArray){
var idx = theIndexOf(key);
console.log("get index >>>>> " + idx);
var obj = errorsDescription[idx];
//if user didn't put correct word i.e. #gmail or 0000
if (data.indexOf(correctKey) < 0) {
if (!elemIn) {
errorArray.push(obj);
elemIn = true;
}
} else {
if (elemIn) {
$.each(errorArray, function(i){
if(errorArray[i].selector === key) {
errorArray.splice(i, 1);
elemIn = false;
}
});
}
}
return [errorArray, elemIn];
}
});
The problem is that when I insert i.e. "test#gmail.com", the error is deleted from the array and when I insert correct data again it tells me that cannot read 'yyy' property of undefined.
Here is my plunker.
https://plnkr.co/edit/l0ct4gAh6v10i47XxcmT?p=preview
In the plunker, type in the fields 'test#gmail' and test0000 for the Number, then remove data then insert again the same data to see the problem
Any help would be much appreciated!

EDIT: Working plunkr here: https://plnkr.co/edit/8DY0Cd5Pvt6TPVYHbFA4
The issue is here:
var obj = errorsDescription[idx];
//if user didn't put correct word i.e. #gmail or 0000
if(data.indexOf(correctKey) < 0){
// console.log("You must put correct word");
if(!elemIn){
errorArray.push(obj);
elemIn = true;
}
}
When your Personal Number error is removed, the logic above pushes undefined to your errorArray (because elemIn is false). Your storeIdErr methond:
$scope.storeIdErr = function(data){
var correctKey = "0000";
var key = "#userId";
var res = {};
if(data != null){
res = $scope.handleError(data, idIn, correctKey, key, $scope.errors);
$scope.errors = res[0];
idIn = res[1];
}
};
reads this value (res[0]) and stores it in $scope.errors which ultimately is iterated over on the next input event by:
function theIndexOf(val){
console.log("find index in array of length: " + errorsDescription.length)
for(var i = 0; i < errorsDescription.length; i++){
if(errorsDescription[i].selector === val){
return i;
}
}
}
due to your factory returning that object when asked for errors. To fix this, you should keep a static list that you never remove from which provides the error definitions. This is what you should refer to when you push to errorArray in your first code block.

The issue you are having is with this block of code here:
$.each(errorArray, function(i){
if(errorArray[i].selector === key) {
errorArray.splice(i, 1);
elemIn = false;
}
});
When you call splice, you are modifying the length of the array. $.each is looping over the length of the array, and is not aware of the length change. (I don't know the internal workings of $.each, but I'm guessing it caches the length of the array before starting, for performance reasons.) So, after you splice out the first error, the loop is still running a second time. At this point, errorArray[1] no longer exists, which is causing your undefined error.
See this question for reference: Remove items from array with splice in for loop