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How to fix "Function returned undefined, expected Promise or value" error when function loops

I have an android application I developed, that allows the sign up of users. I wrote a firebase cloud function that triggers when a User is created, to generate a 5-digit random integer value for the user who just signed up and it stores the generated code in firebase real time database in the following structure.
MainProject
|
|-Codes
|-UniqueUID_1
|-code:72834
|-UniqueUID_2
|-code:23784
The function that I deployed in order to make sure that the code generation is in the backend, is as seen below. There is a value "checker" which is initialised as 0. I use this value to determine when to exit the while loop. Basically I want the function to generate a 5-digit random value, then check the real time database if that generated value exists in all entries under "Codes", then if it does not exist, append it to the Codes under the relevant UID. If it exists, checker remains zero and the loop continues.
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
var checker = 0;
exports.createUserCode = functions.auth.user().onCreate(event => {
while (checker == 0){
var newRand = getUserCode(89999,10000);
var userObject = {
uCode : newRand
};
//run a db query to strategically check value generated
return admin.database().ref("Codes/").orderByChild("uCode").equalTo(newRand).once("value",snapshot => {
if (!snapshot.exists()){
checker = 1;
//add uCode into respective uid slot under Codes
console.log(""+newRand+" : "+event.uid);
return admin.database().ref('Codes/' + event.uid).set(userObject);
}else{
checker = 0;
console.log("uCode "+newRand+" exists");
console.log("uCode generation failed for: "+event.uid);
}
});
}
});
function getUserCode(size, add){
return Math.floor(Math.random()*size+add);
}
I tested it and it worked fine. I thought the problem was solved. However, on the 7th to 11th trial, it gave me a Function returned undefined, expected Promise or value error. I tried it again after a while, and it generated the code fine. Some one else tested it and it brought the same error.
How can I fix this issue to ensure it always works? Thanks in advance.

It's really not clear to me what this function is supposed to do, and the top-level while loop doesn't make sense to me. However, I can see there are a few things wrong with what this code is doing.
First of all, it's depending on the global state checker too heavily. This value will not be the consistent for all function invocations, because they all won't be running on the same server instance. Each running server instance will see a different value of checker. Please watch this video series for more information about how Cloud Functions runs code.
Second of all, when checker has a value of 1 when the function starts, the function will do exactly what the error message says - it will return undefined. It should be pretty easy to see how this happens by reading the code.
To fix this, I suggest first coming up with a clear description of what this function is supposed to do when invoked. Also, I would strongly suggest eliminating dependency on global variables, unless you are absolutely certain you understand what you're doing and the effect they have.

I had the same problem a while ago. ESLint won't allow the function to complete because it evaluates whether every part of your code returns a promise.
From what i can see the first part of the if does return something. Try returning a boolean in the else block.
if (!snapshot.exists()){
checker = 1;
//add uCode into respective uid slot under Codes
console.log(""+newRand+" : "+event.uid);
return admin.database().ref('Codes/' + event.uid).set(userObject);
}else{
checker = 0;
console.log("uCode "+newRand+" exists");
console.log("uCode generation failed for: "+event.uid);
return false;
}

Returning empty string on a input that has a value

I have a date input in my page, which I'm using Daterangepicker framework to populate it.
Here is the code of how I start my page!
$(function(){
startSelectors();
var variaveis = returnInputVars();
var rede = variaveis[0];
var codLoja = variaveis[1];
var period = variaveis[2];
console.log('1.'+rede+' 2.'+codLoja+' 3.'+period);
});
function returnInputVars(){
var rede = $("#dropdown-parceria").val();
var codLoja = $("#dropdown-loja").val();
var periodo = $("#datepicker-range").val();
return [rede, codLoja, periodo];
};
The function startSelectors() is set to start my datepicker and other fields, which is working perfectly. After it, I create a var called "variaveis" to fill
with the values of each field because I will use then later (this functions also works perfectly at other scripts of my page).
Running the page, my console returns this:
The funny thing is, if I type at the console this, the value is shown, just while starting the script is does not work!
Anybody experienced something like this?
***UPDATE
Adding this script to my start function:
console.log($("#datepicker-range"));
The value is shown, but the second console.log don't:
EDIT 1. FIDDLE (Suggested by #halleron)

To ensure things are loaded in the correct order, it is useful to apply a page sniffer code snippet that will scan the page continuously until a condition is met, or until a preset counter limit is reached (to prevent strain on browser memory). Below is an example of what I typically use that would fit your scenario.
I think because you are dealing with asynchronous loading, you can't have a global variable that holds the values in a global scope without an interval to detect when it can be used. Otherwise, it will attempt to read the variable when it is not yet ready.
You can invoke functions anywhere you like. But I would keep all of your variables contained within the page_sniffer_2017() because that is a controlled environment where you know that everything successfully loaded and you know that the variables are ready to be accessed without error.
That way, regardless of connection speed, your functions will only fire when ready and your code will flow, sequentially, in the right order.
Within the ajax success options, always add a class to the body of the document that you can search on to determine if it has finished loading.
$(document).ready(function() {
page_sniffer_2017();
});
function page_sniffer_2017() {
var counter = 0;
var imgScanner = setInterval(function() {
if ($("#datepicker-range").length > 0 && $("#datepicker-range").val().length && jQuery('body').hasClass('date-picker-successfully-generated')) {
var periodoDatepicker = $("#datepicker-range").val(); // ok
console.log(periodoDatepicker); // ok
var variaveis = returnInputVars(replaceDate(periodoDatepicker)); // ok
console.log(variaveis[0], variaveis[1], variaveis[2]);
//startNewSelectors(variaveis);
// start ajax call
generateData(variaveis[0], variaveis[1], variaveis[2]);
clearInterval(imgScanner);
} else {
//var doNothing = "";
counter++;
if (counter === 100) {
console.log(counter);
clearInterval(imgScanner);
}
}
}, 50);
}

Can't overwrite object saved with rhaboo in javascript

I'm trying to save an object with rhaboo in javascript. The first time after initialising it is working but when I'm trying to save it again it gives me the
rhaboo.min.js:1 Uncaught TypeError: Cannot read property 'refs' of undefined error. I pinned down the error to the line where I save the keyArray with notes.write('presentationNotes', keyArray);
How I get the error in detail:
I open my webapplication with a clean localStorage (nothing is saved) and rhaboo gets initialised. After that I navigate to a document and open the notes-div with the notes-button. I write something in the notes-area and hit the notes-submit button to save the notes with rhaboo to localStorage. I do the same for a second document. For now everything works. Both notes get saved correctly so that I have an object like this:
keyArray = {activeDoc1: ['note1', 'note2'], activeDoc2: ['note1', 'note2']}
saved in rhaboo in notes.presentationNotes. Then I reload my webapplication and rhaboo is already initialised. I navigate to the documents as before and check if I can load the saved notes. This works as expected but when I try to hit the notes-submit button again it gives me the aforementioned error. What am I doing wrong?
var notes = Rhaboo.persistent('Presentation Notes');
$(document).ready(function(event) {
var keyArray, activeDoc;
if (!notes.initialised) {
notes.write('initialised', true);
notes.write('presentationNotes', {});
console.log('Rhaboo Initialised');
keyArray = {};
} else {
console.log('Rhaboo already initialised');
keyArray = notes.presentationNotes;
console.log('notes.presentationNotes onLoad = ');
console.log(notes.presentationNotes);
}
//Notes open
$(document).on('click', '#notes-button', function() {
$('.notes-div').show();
activeDoc = $('.node.active').attr('id');
if (notes.presentationNotes[activeDoc] != null) {
//Iterate notes
$.each(notes.presentationNotes[activeDoc], function(index, value) {
$('#notes-area').append(value + '\n');
});
}
});
//Notes save
$(document).on('click', '#notes-submit', function() {
$('.notes-div').hide();
var str = $('#notes-area').val();
var array = str.split("\n");
keyArray[activeDoc] = array;
//Save notes
notes.write('presentationNotes', keyArray);
//Clear textarea
$('#notes-area').val('');
});
}

Without the HTML I haven't been able to try this, so I'm just guessing here, but I suspect your problem will go away if you stop using keyArray and activeDoc. The whole point of rhaboo is that it is not a place to store your data. It IS your data.
I see no transient data in your program, i.e., no data which you actively want to delete when the user goes away and comes back. All the data is supposed to be persistent, therefore it should all be under the Rhaboo.persistent.
That's the philosophy, but to be more specific, I think your problem is here:
keyArray[activeDoc] = array;
When I wonder what keyArray is is find:
keyArray = notes.presentationNotes;
so the earlier line actually says:
notes.presentationNotes[activeDoc] = array;
but it says on the tin that that should read:
notes.presentationNotes.write(activeDoc, array);
The upshot is that that the hooks that make rhaboo work have not been inserted into array, as notes.presentationNotes.write would have done.
When you next said:
notes.write('presentationNotes', keyArray);
it meant:
notes.write('presentationNotes', notes.presentationNotes).
which is clearly not what you meant. Rhaboo doesn't suspect that array has no hooks yet because it can see that notes.presentationNotes does have hooks.
I also forget to use write sometimes, and it really bugs me that JS offers no way to hook into the creation of a NEW key within an object X, no matter what you've done to X. Without that limitation, there'd be no need for write and it could be foolproof.

Refresh to repeat control not working normal after deleting 1 row

I have a field named "selectedTime" in a document, this fields stores the selected timings added by user.Adding times is working perfect.This is back-end.
Now I will explain this issue of selecting date from front end.I have given a button add to add times.The custom control of date-time gets added to repeat control on click of Add button.Even if I check in document it shows the list of selected times.Even this works fine.
Now if I want to delete a selected time from repeat control randomly, it deleted that particular record from document, but on the page the last record of the repeat gets disappears,
I was assuming that this is the issue with partial refresh of repeat control,I have even tried that but no result.Full refresh breaks the page.
java script code for the delete button
`var doc:NotesDocument = database.getDocumentByUNID(context.getUrlParameter("refId"))
var selectedTimes:java.util.Vector = doc.getItemValue("selectedTimes");
if(selectedTimes != null){
var sdtString = getComponent("inputHidden1").getValue();
if(selectedTimes.contains(sdtString))
selectedTimes.remove(sdtString);
doc.replaceItemValue("selectedTimes",selectedTimes);
doc.save();
};
var url:XSPUrl = context.getUrl();
view.postScript("window.refresh('"+url+"')");`
I know it is difficult to understand what i want to explain but any suggestion on this will be appreciated.
Even if anybody have any idea to delete the a field values of a documents,In my case field name is "selectedTimes" and the values are added times in repeat control, Please share.
Edit 1:
//Repeat Control
var doc:NotesDocument = database.getDocumentByUNID(context.getUrlParameter("refId"))
var selectedTimes:java.util.Vector = doc.getItemValue("selectedTimes");
return selectedTimes;

Another try could be link the repeat with a viewScope instead of the document:
1) In the event beforeLoadPage/afterLoadPage: Get the value from the document, and put it in a viewScope variable:
// beforeLoadPage event:
// ... get the doc
viewScope.selectedTimes = doc.getItemValue("selectedTimes");
2) In the repeat control, use the viewScope:
<xp:repeat value="#{viewScope.selectedTimes}"...
3) When an update is done, update both the viewScope and the document:
//...update the View Scope variable and get the document:
doc.replaceItemValue("selectedTimes", viewScope.selectedTimes);
This could be a hint if the document would be added as DataSource:
Do you have the document included in the XPage as a DataSource? In that case, try to get and update the NotesXspDocument instead of the Document from the DB:
XPage:
<xp:this.data>
<xp:dominoDocument var="xspDocument"
action="editDocument"
documentId="#{param.unid}">
</xp:dominoDocument>
</xp:this.data>
SSJS code: work directly with the XspDocument
var selectedTimes:java.util.Vector = xspDocument.getItemValue("selectedTimes");
...
xspDocument.replaceItemValue("selectedTimes", selectedTimes);
This could be a hint if the value would not be removed from the document:
In sdtString you are getting a String value:
var sdtString = getComponent("inputHidden1").getValue();
If you have the time values stored as NotesDateTimes, you will get this type of value inside the Vector and the remove method won't find the String and nothing will be removed.
// In a Vector<NotesDateTime> the String cannot be found:
selectedTimes.remove(sdtString);
Be sure you remove the same type of value you get in the Vector

Variable not updating in script string, yet it updates

Very confused here.
I have a search box which reads a list of school names from my database. When I select a school, the id (from the db) gets put in a hidden textbox.
I also have a search box which reads a list of courses from my database. However, I made the query so that it only reads the courses from the selected school.
It does that, in theory.
I was planning to pass the school id, which I grab from the hidden box, to the search script which in turn passes it to my database query. However, the variable I put my school id in doesn't seem to be updating.. yet it does. Let me explain.
I come on the page. The school for my test account has id 1. The id number in my hidden box is indeed 1. I search for a school which I know has some courses assigned to it: the id number in the box changes to 3.
I have a JS variable called school_id which I declared outside of my $(document).ready. I assume that means it's global (that's what I got taught even though SO told me once it isn't really the correct way to do this. Still have to look into that). I wrote a function which updates this variable when the school search box loses focus:
$("#school").blur(function() {
school_id = $("#school_id").val();
});
A quick javascript:alert(school_id); in my browser bar also shows the updated variable: it is now 3 instead of 1.
Onto the search script part of my page (excerpt of the script):
script:"/profiel/search_richting?json=true&limit=6&id=" + school_id + "&"
As you can see, I pass the school_id variable to the script here. However, what seems to be happening is that it always passes '1', the default variable when the page loads. It simply ignores the updated variable. Does this string get parsed when the page loads? In other words, as soon as the page loads, does it actually say &id=1? That's the only idea I can come up with why it would always pass '1'.
Is there a way to make this variable update in my script string? Or what would be the best way to solve this? I'm probably missing out on something very simple here again, as usual. Thanks a lot.
EDIT
Updated per request. I added a function getTheString as was suggest and I use the value of this function to get the URL. Still doesn't work though, it still seems to be concatenating before I get a chance to update the var. HOWEVER, with this code, my ajax log says id:[object HTMLInputElement], instead of id:1. Not sure what that means.
<script type="text/javascript">
var school_id;
$(document).ready(function() {
$("#school").blur(function() {
school_id = $("#school_id").val();
});
// zoekfunctie
var scholen = {
script:"/profiel/search_school?json=true&limit=6&",
varname:"input",
json:true,
shownoresults:false,
maxresults:6,
callback: function (obj) { document.getElementById('school_id').value = obj.id; }
};
var as_json = new bsn.AutoSuggest('school', scholen);
var richtingen = {
script: getTheString(),
varname:"input",
json:true,
shownoresults:true,
maxresults:6
};
var as_json2 = new bsn.AutoSuggest('studierichting', richtingen);
});
function getTheString() {
return "/profiel/search_richting?json=true&limit=6&id=" + school_id + "&";
}
</script>

This is because the URL is static, it is not updated as the ID changes.
You should update the URL as part of the code you wrote to get the ID:
$("#school").blur(function() {
school_id = $("#school_id").val();
// update URL here ...
});

Aren't you concatenating script:"/profiel/search_richting?json=true&limit=6&id=" + school_id + "&" before the event is fired and the var updated?

Okay. So the problem was my third party plug-in instead of the code I wrote. I fixed this by editing the code of the autoSuggest plugin so it now includes my id field in the AJAX request.
var url = this.oP.script+this.oP.varname+"="+encodeURIComponent(this.sInp)+"&id="+ $("#school_id").val();
Thanks to everyone who tried to help me out!