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When I try to use Node.js in Visual Studio Code’s terminal, I get “document is not defined” error messages

I’m brand new to programming and I’m currently working on a MySQL database. I’m using Visual Studio Code for all of my JavaScript, HTML, and CSS files.
I have a JavaScript server file that is giving me issues. Our professor gave us his code for the server JavaScript file (which is posted below), his client JavaScript file (which is named contacts.js), and his HTML file.
He told us to open the server JavaScript file, open a terminal and type: node contacts.js. However, doing this gives me error messages that say that the document is not defined.
Occasionally, I'll even get "module not found" errors.
We just did a similar project last week and the terminal worked just fine with a similar node.js command, but I’m running into issues now and don’t know what to do. Hours on Google haven’t helped at all and my professor can’t be contacted for the entire week.
I’m not sure how to get beyond this “document not defined” error. Any help would be appreciated.
Below is the server JavaScript file:
// The following statements are for database connection and queries
var mysql = require('mysql'); // use the msql libraries. Must use 'npm install msyql --save' before using
var bodyParser = require('body-parser'); // use the body-parser library for JSON use. Must 'npm install body-parser --save'
// Set up the SQL connection to the MYSQL database. This will all need to match what you set up in your DB
var connection = mysql.createConnection({
host:'localhost',
user: 'mike',
password: '********',
database: 'contacts'
});
// do the actual connecting by calling the connect method and log the result
connection.connect();
console.log("After connection to DB established in server, setting up web server");
//The following are for web server setup - we are using the express library that makes this all pretty easy
const express = require('express'); // use express library. must use 'npm install express --save'
const cors = require('cors'); // use cors library. must use 'npm install cors --save'
const app = express(); // get the express application object
const path = require('path'); // use the path library for managing paths. must use 'npm install path --save'
const port = 3000; // constant for the port we're using.
// set up the use of JSON url-encoding. Allows us to put all the arguments in the url
app.use(bodyParser.urlencoded({extended: false}));
app.use(bodyParser.json());
// We want to also serve static pages. This command sets that up. In my case, I created a subdirectory called 'public'
// and put the main html page (contacts.html), the javascript client file (contacts.js) and the CSS file (contacts.css)
// in that directory, and therefore I can get everything I need by just goint to (localhost:3000) and it all just works
app.use(express.static('public'));
// This is our main save handler (express calls these 'middleware'). The request coming from the client is a post
// and all the parameters/values are in the query object in the request object (req).
// All the field names here must match the names in the form (name='blah') which we use when we craft the request
// in the javascript saveContact().
// NOTE: we have to use the cors() method to make this all work. Look up cors (Cross-Origin Resource Sharing) to learn about it
app.post('/save', cors(), function (req, res) {
console.log("trying to save contact (post)"); // Log what we're doing
console.log(req); // log the actual request
var curId = req.query.Id; // Get the Id from the query object
var firstName = req.query.fname; // get the fname from the query object
var lastName = req.query.lname; // get the lname from the query object
var age = req.query.age; // etc. etc. etc.
var phone = req.query.phone;
var email = req.query.email;
// We can use the same handler for both cases of saving information:
// 1)we INSERT the new contact in the DB - the Id is 0 in this case
// 2)we UPDATE an existing contact in the DB - the Id is the correct Id for the contact we're updating
// Here we're crafting the appropriate SQL statements using the values above - either INSERT or UPDATE
if (curId > 0) {
var sql = `UPDATE contacts SET fname = '${firstName}', lname = '${lastName}', age = ${age}, phone = '${phone}', email = '${email}' WHERE Id = ${curId}`;
} else {
var sql = `INSERT INTO contacts (fname, lname, age, phone, email) VALUES ('${firstName}', '${lastName}', '${age}', '${phone}', '${email}')`;
}
// Here we're creating the query and the callback function for when we get a response from the DB asynchronously
// This same method executes the SQL call to the database connection we established earlier (above)
connection.query(sql, function (err, result) {
console.log("Trying to save contact into DB"); // log what we're doing
if (err) throw err; // If we get an error, send the error along
console.log(result.affectedRows + " record(s) saved");
res.status(201).send(result); // set the status code (201 = successful add) and send it
console.log(`result of post is: ${result}`); // log the result
console.log(result);
});
});
// This handler is for deleting a user given a valid Id.
// NOTE: we have to use the cors() method to make this all work. Look up cors (Cross-Origin Resource Sharing) to learn about it
app.post('/delete', cors(), function (req, res) {
console.log("trying to delete contact (post)"); // log what we're doing
console.log(req); // log the actual request we received
var curId = req.query.Id; // get the Id from the query object
console.log(curId); // log the Id
// As long as we have a valid Id (in variable curId), we craft the sql statement and execute the query
// all the SQL commands are asynchronous so we provide a callback function
if (curId > 0) {
var sql = `DELETE FROM contacts WHERE Id = ${curId}`; // This is the right SQL statement
connection.query(sql, function (err, result) {
console.log("Trying to delete contact from DB"); // log what we're trying to do
if (err) throw err; // if we get an error, pass it along to the client
console.log(result.affectedRows + " record(s) deleted");
res.status(200).send(result); // otherwise set the status to success (200) and send the result to the client
console.log(`result of post is:`); // log the result
console.log(result);
});
}
});
// THis is our static GET Handler if you just open a browser and type in 'http://localhost:3000'. the '/' means root
// and so this our default page (often called 'index.html' but in this case it's our 'contacts.html')
// Simply send the contacts.html page by getting the default path (wherever we have this javascript file)
app.get('/', function (req, res) {
console.log(req.params);
res.sendFile(path.join(__dirname + '\\contacts.html'));
});
// This is our handler for getting the full list of contacts
// NOTE: we have to use the cors() method to make this all work. Look up cors (Cross-Origin Resource Sharing) to learn about it
app.get('/list', cors(), function (req, res) {
console.log(`inside list GET function, req object is ${req}`);
console.log(req);
// Craft the simple select statement that just gets everything in the contacts table
var sql = `SELECT * FROM contacts`;
//Create the query and execute it, sending the appropriate result back to the client
connection.query(sql, function (err, result) {
console.log(`Trying to get list from DB - result is ${result}`);
console.log(`Inside get list - result first row is ${result[0]}`);
if (err) throw err; // if we get an error, pass it along to the client
res.send(result); // simply send the result of the query to the client.
console.log(`result of GET to list is: ${result}`);
});
});
// This is what actually starts the express server, listening on the port constant we defined at the beginning
// of the file (in this case I'm using 3000) and logging what we're doing.
app.listen(port, () => console.log(`Example app listening on port ${port}!`));
Below is the client JavaScript file:
// This JavaScript file is in support of the contacts application.
// Users can see and manage all their contacts, where a contact is [Id, firstname, lastname, age, phone, email]
// There are functions to manage the http interactions with the server backend
// and to manage the screen/user experience
// This is a globally available array of contacts we get back from the server. Set it initially to an empty array
document.contactList = [];
// This is the function queries the server (using an HTTP GET) to get the list of contacts
// We save the contacts to a globable variable in the document (contactList) and we fill
// both the table at the bottom of the document and a drop-down list used for management
// both of those functionality are function calls ('fillContactTable()' and 'fillContactSelect()')
function getContacts() {
console.log(`Getting contact list from server`); // log what we're doing
var xhttp = new XMLHttpRequest(); // create a variable for HTTP protocol
xhttp.onreadystatechange = function() { // callback function for when a response occurs
console.log(this.responseText); // log the response
// readyState is the XMLHttpRequest state that means we're done. Status is what is returned from the server
// a status code anywhere in the 200's is success. SO if we're done and get a success return code, then we're good!
if (this.readyState == 4 && (this.status >= 200 && this.status < 300)) {
console.log(`Got the contact list successfully`); // Log that we're good
document.contactList = this.responseText; // The response is the actual list of contacts.Set to globabl var in document
fillContactTable(); // Fill the table
fillContactSelect(); // Fill the drop down list (select element)
} else {
console.log(`failed to get contact list`); // Log failure if that's what we got
}
}
// We've set the callback function that handles the result. This is the actual setting up the http request (the open method)
// and the actual sending of the http request (send method)
xhttp.open("GET", "http://localhost:3000/list", true);
xhttp.send();
}
// Given an Id of a contact, get the rest of the contact information and return it
// The pLocal parater is in case we want to get the contact information from the server instead of getting it from
// the global variable (document.contactList). Default is to be local.
function getContactById(pId, pLocal = true) {
console.log(`Getting contact by ID = ${pId}`); // log what we're doing
if (pLocal) { // If we're local, get the data from document.contactList
var contactsJSON = JSON.parse(document.contactList); // parse the contactList into JSON format - easier to deal with
// Loop through all the contacts in the JSON formated list of contacts to look for the one we want (by Id)
for (loopIndex = 0; loopIndex < contactsJSON.length; loopIndex++) {
if (contactsJSON[loopIndex].Id == pId) { // if Id's match, we're good but log what we found
console.log(`Found contact in getContactById. Index = ${loopIndex}`);
console.log(contactsJSON[loopIndex]);
return contactsJSON[loopIndex]; // Return the found contact
}
}
console.log(`Did not find the contact in getContactById`); // log the fact that we didn't find it and return null
return null;
// For now, if we're not local just return null. Will add the code to get the data from the server later
} else {
return null;
}
}
// Simple function that just clears the form that we use for showing, creating new, and updating contacts
function clearEditForm() {
console.log("clearing the contact form"); // Log what we're doing
// Set all the values to empty (or 0 for the Id - that has to be a number)
document.getElementById('contact_id').value = 0;
document.getElementById('contact_fname').value = "";
document.getElementById('contact_lname').value = "";
document.getElementById('contact_age').value = "";
document.getElementById('contact_phone').value = "";
document.getElementById('contact_email').value = "";
// Now control the user experience. Hide the ID fields and change the name of the button to "Insert"
document.getElementById('contact_id').hidden = true;
document.getElementById('contact_id_label').hidden = true;
document.getElementById('save_button').innerHTML = "Insert Contact";
document.getElementById('save_button').name = "Insert Contact";
}
// Main function that saves the contact form. We have two cases to deal with:
// 1) We're inserting a new contact. In that case, the Id (curId below) will be 0
// 2) We're updating an exesting contact. In that case, the Id will NOT be 0
// If the ID is not a number >= 0, we have a problem so we don't do anything
function saveContact() {
console.log("Attempting to save contact"); // Log what we're doing
// Get all the values from the elements in the form by name.
var curId = document.getElementById('contact_id').value;
var curFName = document.getElementById('contact_fname').value;
var curLName = document.getElementById('contact_lname').value;
var curAge = document.getElementById('contact_age').value;
var curPhone = document.getElementById('contact_phone').value;
var curEmail = document.getElementById('contact_email').value;
console.log(`Trying to save contact in saveContact. Id = ${curId}`);
// As long as we have a valid Id (number at least 0) we'll make the http request (a POST)
if (curId >= 0) {
var xhttp = new XMLHttpRequest(); // Create a new HTTP object and put it in xHTTP variable
// As in all of our interactions implementing http, we supply a callback function for when we actually get a response
// Remember, all http request/responses should be asynchronous, and so we have to use callbacks
xhttp.onreadystatechange = function() {
console.log(this.responseText); // log what's happening
// If readyState shows we're done (value == 4) and status code is in the 200's we got a success response
if (this.readyState == 4 && (this.status >= 200 && this.status < 300)) {
console.log(`saved the contact successfully`); // Log our success
getContacts(); // Re-get our contact list since it has changed
} else {
console.log(`failed to save contact `); // Log our failure response
console.log(this.status); // log the actual status code
console.log(this.responseText); // log the actual response text
}
}
// Here we're crafting the http POST request with all the parameters urlencoded. Look up url encoding to understand it
// As usual, the open method is used to set up the call, and the send method actually sends the request
xhttp.open("POST", `http://localhost:3000/save?Id=${curId}&fname=${curFName}&lname=${curLName}&age=${curAge}&phone=${curPhone}&email=${curEmail}`, true);
xhttp.send();
}
}
// Function to delete a contact by creating the right server http request (a POST)
// We'll pass the Id of the contact we want to delete in the url (url-encoded)
// We'll get the name of the contact to be deleted and prompt the user to verify that they want to really delete the contact
// look up the window method 'confirm' to understand how that works
function deleteContact() {
console.log("Attempting to delete contact"); // Log what we're doing
var contactList = document.getElementById('contacts_list'); // get the drop-down select element in the form
var curId = contactList.value; // get the value of the form, which will be an Id of the contact to be deleted
var curIndex = contactList.selectedIndex; // We need the index of the option chosen to get the name for prompting the user
var curName = contactList.options[curIndex].text; // get the name from the option list based on the index
console.log(`Trying to verify delete. curid = ${curId}, curIndex = ${curIndex}, and curName = ${curName}`);
// Prompt the user to confirm using the window.confirm method. If they say ok, confirm returns true
// if they say cancel, confirm returns false. We're checking for the false, thus the not (!) at the beginning of the condition
if (!confirm(`Are you sure you want to delete contact: ${curName}?`)) {
return; // If we're here they said cancel, so just return out of here
}
console.log(`Trying to delete contact in fillEditForm. Id = ${curId}`);
if (curId.length > 0) { // Make sure we have a good Id
var xhttp = new XMLHttpRequest(); // create the http object
// Here's our callback for the asynchronous return. As long as we get a good status code, we update the form appropriately
xhttp.onreadystatechange = function() {
console.log(this.responseText); // log the actual response
// readyState 4 means we're done, and status in the 200's means success, so re-get the contact list from the server
if (this.readyState == 4 && (this.status >= 200 && this.status < 300)) {
console.log(`deleted the contact successfully`);
clearEditForm(); // clear the form since we deleted the contact
getContacts(); // get the contacts from the server
} else {
console.log(`failed to delete contact list`);
}
}
// Create the actual request and send it.
xhttp.open("POST", `http://localhost:3000/delete?Id=${curId}`, true);
xhttp.send();
}
}
// Simple function to clear the table element. We delete all the rows backwards. Make the function generic by allowing
// a parameter (pTable) which is the name of the table to be reset if there is more than one on the form
function tableDeleteRows(pTable = "") {
var curTable;
if (pTable.length == 0) {
curTable = document.getElementById('contacts_table');
} else {
curTable = document.getElementById(pTable);
}
// We start at the end of the rows (rows[length-1]), deleting backwards until we delete all of them
for (i = curTable.rows.length - 1; i >= 0; i--) {
curTable.deleteRow(i);
}
}
// Simple function to clear a drop-down select element. We delete all the rows backwards. Make the function generic by allowing
// a parameter (pSelect) which is the name of the select element to be reset if there is more than one on the form
function selectDeleteOptions(pSelect = "") {
var curSelect;
if (pSelect.length == 0) {
curSelect = document.getElementById('contacts_list');
} else {
curSelect = document.getElementById(pSelect);
}
// Go backward from the end of the list of options in the select, removing them until we remove all of them
for (i = curSelect.length - 1; i >= 0; i--) {
curSelect.remove(i);
}
}
// Assuming we have a contact chosen in the drop-down select element, fill the edit form with all the values for that contact
function fillEditForm() {
console.log("filling the contact form"); // Log what we're doing
var contactList = document.getElementById('contacts_list'); // get the drop-down list
var curId = contactList.value; // the selected element Id is the value of the list
console.log(`Trying to find contact in fillEditForm. Id = ${curId}`);
var curContact = getContactById(curId); // Get the whole contact by calling the function
console.log(curContact); // log the contact we're using to fill the form
// As long as we have a good contact, we fill the form
if (curContact != null) {
document.getElementById('contact_id').value = curContact['Id'];
document.getElementById('contact_fname').value = curContact['fname'];
document.getElementById('contact_lname').value = curContact['lname'];
document.getElementById('contact_age').value = curContact['age'];
document.getElementById('contact_phone').value = curContact['phone'];
document.getElementById('contact_email').value = curContact['email'];
}
// after we fill the form, we set elements appropriate to things like update and delete instead of add new
document.getElementById('contact_id').hidden = false;
document.getElementById('contact_id').disabled = true;
document.getElementById('contact_id_label').hidden = false;
document.getElementById('save_button').innerHTML = "Update Contact";
document.getElementById('save_button').name = "Update Contact";
}
// This function fills the table at the bottom of the document with all the contacts and all the information
function fillContactTable() {
console.log("Filling the contacts table in the form"); // Log what we're doing
tableDeleteRows("contacts_table"); // Reset the table
// if we don't have anything in the global contact list - forget it and return
if (document.contactList.length == 0) {
console.log("the contact list/array is empty!");
return;
}
// We have contacts in the global array, so first parse the array into JSON and process it
var contactsJSON = JSON.parse(document.contactList);
var properties = ['Id', 'fname', 'lname', 'age', 'phone', 'email']; // we need the property names
var tr, curRow; // variables for table properties
var contactTable = document.getElementById("contacts_table"); // get the table element
// cycle through the rows in the contacts array
for (var rowIndex = 0; rowIndex < contactsJSON.length; rowIndex++) {
console.log(`Creating table rows, rowindex is ${rowIndex}`);
tr = document.createElement('tr'); //create a new table row element
curRow = contactsJSON[rowIndex]; // get the current row from the array
console.log(curRow); // log the data in the current row
// Cycle through the columns - defined in the property array above and add column elements to the row in the table
for (var i = 0; i < properties.length; i++) {
console.log(`Creating table columns for row ${i}, property is ${properties[i]} value is ${curRow[properties[i]]}`);
var td = document.createElement('td'); // create a data element for the column
td.appendChild(document.createTextNode(curRow[properties[i]])); //Append the property data to the new data element
tr.appendChild(td); // append the new data element to the row element
}
contactTable.appendChild(tr); // append the row element to the table element
}
console.log("Finished procesing contacts list");
}
// Fill the drop-down select. First reset the select (removing all options), then recreate it
function fillContactSelect() {
console.log("Filling the contacts drop down select in the form"); // log what we're doing
selectDeleteOptions("contacts_list"); // Reset the select element clearing all options
// if we don't have anything in the global contact list - forget it and return
if (document.contactList.length == 0) {
console.log("the contact list/array is empty!");
return;
}
// We have contacts in the global array, so first parse the array into JSON and process it
var contactsJSON = JSON.parse(document.contactList);
var properties = ['Id', 'fname', 'lname']; // only need Id, fname, lname for drop down
var option, curRow; // variables for table properties
var contact = document.getElementById("contacts_list"); // get the select drop down element
// cycle through the rows in the contacts array
for (var rowIndex = 0; rowIndex < contactsJSON.length; rowIndex++) {
console.log(`Creating select items, rowindex is ${rowIndex}`);
option = document.createElement('option'); //create a select option element
curRow = contactsJSON[rowIndex]; // get the current row from the array
console.log(curRow); // log the data in the current row
// the value of this option will be the id, since that's what we'll use to get a contact. The text is fname + lname
option.value = curRow["Id"];
option.appendChild(document.createTextNode(`${curRow['fname']} ${curRow['lname']}`));
contact.appendChild(option); // append the option to the select element
}
console.log("Finished procesing contacts list");
}
// When the windo first loads, get the list of contacts which will also fill the table and drop down list
window.onload = function() {
getContacts();
};

You are running the wrong JS file. You want to do:
node contactserver.js
At the moment you are running contacts.js, which is client-side code.
To expand on this, you're seeing that error because document is a global variable available in browsers, but not in Node.js. Frontend code designed to run in a browser often relies in browser APIs that simply don't exist on a server, so attempting to run a client-side only file in a server environment will throw errors when it can't find global objects that only exist in a browser.
(Props to #Jon Church for the explanation from the comments below)

Turns out that contacts.js was the wrong file. Typing into the terminal: node contactsserver.js was the solution.

Meteor: sending the document id via email

I have a newsletter which relies on meteor's email package.
As soon as an admin submits a new news & events entry to the collection, all subscribers receive this via email. This also works.
However, I want to have add the new concrete link of the news & events entry to the page.
The route for the news and events page:
// Specific news and events
Router.route('/news-and-events/:_id', {
name: 'newsAndEventsPage',
waitOn: function(){
return [
Meteor.subscribe('newsevents'),
Meteor.subscribe('images'),
Meteor.subscribe('categories'),
Meteor.subscribe('tags'),
]
},
data: function(){
return NewsEvents.findOne({_id: this.params._id});
},
});
The admin route (a form page) for adding a new entry:
// Admin news
Router.route('/admin-news-events', {
name: 'adminNewsEvents',
waitOn: function(){
return [
Meteor.subscribe('newsevents'),
Meteor.subscribe('images'),
]
},
data: function(){
return false
},
});
After submitting the post to the collection, I tried to catch the entry and pass the id, but I just get undefined.
My admin template.js (edited):
'submit form': function (evt, template) {
evt.preventDefault();
var temp = {};
temp.title = $('#title').val();
temp.description = $('#description').summernote('code');
temp.type = $('input[name=netype]:checked').val();
temp.createdAt = moment().format('ddd, DD MMM YYYY hh:mm:ss ZZ');
Meteor.call('NewsEvents.insert', temp);
Bert.alert("New entry added.");
//Fire the email to all Subscribers
var entry = NewsEvents.findOne(this._id);
var entryId = entry.id;
//NOT WORKING
var news = '<a href='+Meteor.absoluteUrl()+'news-and-events/'+entryId+'></a>';
for (i = 0; i < Subscribers.find().count(); i++) {
var email_ = Subscribers.find().fetch()[i].email;
Meteor.call('sendEmail',
email_, //To
'Open Strategy Network <xxx.yyy#zzz.yyy.xx>', //from
'Open Strategy Network News and Events', //subject
news);
}
}
Server methods:
Meteor.methods({
'NewsEvents.insert': function (doc) {
if (this.userId) {
NewsEvents.insert(doc);
}
}
});
...
//Send emails
'sendEmail': function (to, from, subject, text) {
// check([to, from, subject, text], [String]);
this.unblock();
Email.send({
to: to,
from: from,
subject: subject,
html: text
});
},
Thanks a lot.

.find() returns a cursor, not an object. You can either do:
var entry = NewsEvents.findOne(this._id);
var entryId = entry.id;
Or more simply since you already have the _id:
var entryId = this._id;
Or even more simply:
var news = '<a style:"text-decoration: none;"
href='Meteor.absoluteUrl()+'news-and-events/'+this._id+'></a>';
Also, you are trying to send the email while your insert is happening asynchronously.
Meteor.call('NewsEvents.insert', temp); // this might take some time to complete
var entry = NewsEvents.findOne(this._id); // `this` is not going to refer to the just added NewsEvent
Instead, do the notifications in a callback from the method:
Meteor.call('NewsEvents.insert', temp, function(err, result){
if ( !err ){
// assuming that `result` will be the _id of the inserted object!!
var news = '<a href='+Meteor.absoluteUrl()+'news-and-events/'+result+'></a>';
Subscribers.find().forEach(function(s){
Meteor.call('sendEmail',
s.email, //To
'Open Strategy Network <violetta.splitter#business.uzh.ch>', //from
'Open Strategy Network News and Events', //subject
news
);
}
}
});
Your NewsEvents.insert method needs to return the _id of the inserted object:
Meteor.methods({
'NewsEvents.insert'(doc) {
if (this.userId) return NewsEvents.insert(doc);
}
});
Now, even the above will be slow since you're doing Meteor.call() in a loop. Secondly, you've opened up your server as a mail relay since anyone can use the sendEmail method to send any email to anyone from the console inside your app. If you want to do this efficiently, put the notification code inside your NewsEvents.insert method and do it all on the server without all the back and forth!!

If I understood correctly, you want to have ID of the inserted document. Its fairly simple.
In the method that inserts:
var docId = Somethings.insert({ //fields here });
Now you can use that docId in the same method for sending emails.
If you also want to send the documentId to the client side, you can use error, result in Meteor.call() like this:
Meteor.call('methodName', arg, arg2, function(err, res){
if(!err){
//do something with res. in this case the res is inserted docId as I returned docId in the method
Router.go('/some-route/' + docId)
} else {
//do something with err
}
});
The error above comes from errors you throw in methods. For the result, you need to return a value which can be the inserted docId:
return docId
Tidied up method:
methodName: function (arg, arg2){
//equals to err in the `Meteor.call()`
if(arg !== 'something'){
throw new Meteor.Error('This is an error')
}
//insert new document
var docId = Somethings.insert({
fieldOne: arg,
fieldTwo: arg2
});
//send email to each subscriber. I don't know your exact DB fields so, its up to you. You did this in a different call.
var cursor = Subscribers.find();
cursor.forEach(function(ss){
//send email here. You can use each subscriber data like ss._id or ss.email. However you insert them...
});
//Equals to res in `Meteor.call()`. sends a result to the client side method call. inserted docId in this case
return docId
},
PS: If this doesn't answer you question, that means I didn't understand what you're trying to achieve exactly. Leave me a comment and I'll edit the answer.
EDIT
I used one method for both sending emails and inserting the document but still, you can pass error/result exactly like how I did and then do another call for emails using the id in result.

Parse.com get users from subquery in other class Cloud Code

I have the class Friends on Parse:
Class Friends{
"from" : Pointer(_User)
"to" : Pointer(_User)
"allowSee" : Boolean
"block" : Boolean
"createdAt" : Date
"updatedAt" : Date
}
I have a Parse.Query where I get my friends, but this is Class Friends not class User. I try do a cicle for get the users in el field "from" but the array users return void
var user = Parse.User.current();
var me = {__type: 'Pointer',className: '_User', objectId: user.id}
var qFriends = new Parse.Query("Friends");
qFriends.equalTo("to", me);
qFriends.equalTo("allowSee", true);
qFriends.find().then(function(results){
for (i = 0; i < results.length; i++) {
var uFriendId = results[i].get("from").id;
var getUserById = new Parse.Query("_User");
getUserById.equalTo("objectId", uFriendId);
getUserById.first({
success: function(user) {
users.push(user);
},
error: function(error){
console.log(error);
}
})
}
return users;
}).then(function(friends){
response.success(friends);
}, function(error){
response.error();
});
Do exist way of get users by array of objectIds?, example:
var from =["f8dfg3","32fsg5s","43t4gsd"];
var arrUsers = getUser(from); // return array of PFUser with objectId in array from
Thanks,

Because your Friends class keeps pointers to users, there is a good way, in a single step, to eagerly fetch the related users. Before running the query, add:
qFriends.include("from");
qFriends.include("to");
Upon completion, the related users will be fetched, so you can get at them as follows:
qFriends.find().then(function(results){
for (i = 0; i < results.length; i++) {
var friend = results[i];
var fromUser = friend.get("from");
var toUser = friend.get("to");
// these will be fetched, so you can say things like:
console.log(fromUser.username);
// and so on
Incidentally, there's no need to build a pointer from the current user to qualify the query, the current user will do just fine as follows:
qFriends.equalTo("to", Parse.User.current());
Also, your goal should be covered with just the include() advice above, but at some point you might need to query the related objects in the results block the way your original post code attempts. The OP code makes two mistakes there: (1) you can just fetch(result.get("from")), the object -- no need to extract the objectId and call either get() or first() as you do. (2) all of those functions just named are asynchronous. The loop that launches them will terminate before any of them begin, so the line return users; will necessarily return nothing. The correct approach is to fill an array with the fetch()-returned promises and then return a new promise from Parse.Promise.when(fetchPromises);

Return all models from mongodb as an object or array?

I am using sockets with mongodb, for a user who is trying to create a new name, I need to check all the models in the database to see if it exists.
I am doing it all wrong, basically I am trying to do something like this.
var allUsers = [];
models.Message.find({}, function(err, data) {
for(var i=0; i < data.length; i++) {
allUsers.push(data[i].username);
}
});
console.log(allUsers)
I'm sitting here struggling even getting the allUsers out of the function, and I am thinking this is not even the best way to do this. With allUsers I was just going to check to see if the new username existed in the array.
So to futher extend what I am doing here is some socket.io code. I was going to run some validation like this if I could get the allUsers to work.
socket.on('new user', function (data, callback) {
if(data in allUsers) {
callback(false);
} else {
callback(true);
socket.userName = data;
socket.connected = true;
users[socket.userName] = socket;
io.sockets.emit('user name', {usernames: users[socket.userName].userName, connected: users[socket.userName].connected});
}
});
But without it working, this is no good. So my question is with what I have provided (socket.io, mongodb) how do I get all the models and validate if a new user which is passed in data exists in the database?

models.Message.find is async, the result of the async operation is only available when the async operation has finished.so console.log(allUsers) will always yield an empty array.
should be something like (pseudo js code):
socket.on('new user', function (data, callback) {
models.User.findOne({username:data.username},function(err,user){
if(err){/*deal with error here */}
else if(user){/*username already taken
respond with appropriate socket message here */
socket.emit('user name already taken',{somemessage});
}
else{/* user with username not found */
/*create new user into database then emit socket message */
var user = new models.User(data);
user.save(function(err,user){
socket.emit('user name',{somemessage});
})
}
});
});

Serial Promises and Response.Success in Cloud Code

I'm a little confused about where to place a response.success() when using serial Promises.
Here's the situation: I've got a cloud function that accepts an array of email addresses and the current user. The function does the following:
Finds the current user based upon it's user object id.
Iterates over the array of emails addresses
Find if there is an existing user for each given email address
If there is an existing user, we check to see if the existing user and the current user are friends
If they are not friends, it creates a friendship.
Now when I run this function without a response.success(), it does exactly what I expect it to and the friendships entries are created. But no matter where I place the response in the code, I get the resulting response.success message and none of the serialized promises execute.
Why the resulting success/failure matters: I'm executing this function from an iOS app and I'd like to properly handle the success or failure cases correctly on the iOS side.
Here is the cloud function:
Parse.Cloud.define("friendExistingUsers", function(request, response) {
// Get our parameters
var addresses = request.params.emailAddresses;
var userId = request.params.user;
// Query for our user
var userQuery = new Parse.Query("User");
userQuery.equalTo("objectId", userId)
userQuery.first().then(function(currentUser) {
// if we find the user, walk the addresses
var promise = Parse.Promise.as("success");
_.each(addresses, function(address) {
console.log(address);
// add a then to our promise to handle whether a relationship is
// being created.
promise = promise.then(function() {
// find if there is a user for that address
var emailQuery = new Parse.Query("User");
emailQuery.equalTo("email", address);
emailQuery.first().then(function(addressUser) {
if (typeof addressUser != 'undefined') {
// found one.
console.log(addressUser);
// figure out if our current user and this user are
// friends.
var friendQuery = new Parse.Query("FVFriendship");
friendQuery.equalTo("from", currentUser);
friendQuery.equalTo("to", addressUser);
friendQuery.first().then(function(relationship) {
if (typeof relationship != 'undefined') {
// if they are, we need to pass.
console.log("Found a relationship: " = relationship)
} else {
// They are not. Add the friendship
var Friendship = Parse.Object.extend("FVFriendship");
var friendship = new Friendship();
friendship.set("from", currentUser);
friendship.set("to", addressUser);
friendship.save().then(function(result) {
console.log("Created a friendship: " + result)
});
};
});
} else {
// we did not find a user for that address
console.log("No user for " + address);
};
});
});
});
console.log(promise);
return promise;
}).then(function() {
response.success("success");
});
});
Thanks in Advance. Let me know if there's anything else I can add.

Your .then callback function attached to promise should return a promise. Missing this is a common mistake when using promises.
Also Parse doesn't seem to show objects with console.log as browsers do, so I wrap them into JSON.stringify().