Understanding promises a little more - javascript

I'm struggling to make this works. i'm dealing with sequelize promisses and i want to return the queried elements to the view, but instead its returning null. I know its because promises are async requests and it does not return a result immediatly after you call it, ok, but how to return the values, put it into an array and than return the array?
this is the code i have so far.
router.post('/register', function(req, res, next) {
var sales = req.body.sales;
var person = req.body.personID;
var promisses = [];
var delivery = req.body.delivery;
for(var i =0;i<sales.length;i++){
var product_id = sales[i].product_id;
var amount = sales[i].amount;
var price = sales[i].produto_price;
var salePromisse = Sale.create({
'product_id': product_id,
'person_id': person,
'amount': amount,
'price': price,
'total': amount*price
});
//i couldnt find a word which describes what movimentacao means...lets keep it.
var movimentacao = Movimentacao.create({
"tipo": 0,
"id_product": product_id,
"id_provider": "",
"data": new Date(),
"price": amount*price
});
promisses.push(salePromisse);
promisses.push(movimentacPromisse);
}
Promise.all(promisses).then(function (promissesArray){
var name = "";
var suc = 0;
var total = 0;
var salesResult = [];
var salesObject = {};
if(!delivery){
res.send({msg: "aaaaa"});
}else{
promissesArray.forEach(function(pro){
if(pro!==null && pro !== undefined){
if(pro['$modelOptions'].tableName === undefined){
Product.findById(pro.product_id).then(function (product){
salesObject.product = product.name;
salesObject.price= pro.price;
salesObject.amount = pro.amount;
salesObject.total = pro.total;
total += salesObject.total;
salesResult.push(salesObject);
salesObject = {};
return Person.findById(per);
}).then(function (person) {
name = person.name;
});;
}
}
});
//here is where i would like to return to the view salesResult and name.
//res.render("folder/view", {sales: salesResult, person: name});
console.log(salesResult);
}
});
});
Well, the promisses array has the CREATE instance for each of my models, and i'm creating a few types of it.
I want to insert on the database, check if the promise resolved is dealing with an specific table (the field modelOptions is undefined on it, i already debugged), query all the other results because on the promisses array i have just the id, and than put into the array to be able to return to the view, but on the console.log on the last line, it returns null. How can i improve the code to be able to do all i want and than return to the view?
Dont worry, all the model related variables are beeing declared above.
Thanks.

Related

JavaScript - Issues recovering a map in an object after being saved in localStorage

I've been dealing with this for some time. I've a list of sections in which the user checks some checkboxes and that is sent to the server via AJAX. However, since the user can return to previous sections, I'm using some objects of mine to store some things the user has done (if he/she already finished working in that section, which checkboxes checked, etc). I'm doing this to not overload the database and only send new requests to store information if the user effectively changes a previous checkbox, not if he just starts clicking "Save" randomly. I'm using objects to see the sections of the page, and storing the previous state of the checkboxes in a Map. Here's my "supervisor":
function Supervisor(id) {
this.id = id;
this.verif = null;
this.selections = new Map();
var children = $("#ContentPlaceHolder1_checkboxes_div_" + id).children().length;
for (var i = 0; i < children; i++) {
if (i % 2 == 0) {
var checkbox = $("#ContentPlaceHolder1_checkboxes_div_" + id).children()[i];
var idCheck = checkbox.id.split("_")[2];
this.selections.set(idCheck, false);
}
}
console.log("Length " + this.selections.size);
this.change = false;
}
The console.log gives me the expected output, so I assume my Map is created and initialized correctly. Since the session of the user can expire before he finishes his work, or he can close his browser by accident, I'm storing this object using local storage, so I can change the page accordingly to what he has done should anything happen. Here are my functions:
function setObj(id, supervisor) {
localStorage.setItem(id, JSON.stringify(supervisor));
}
function getObj(key) {
var supervisor = JSON.parse(localStorage.getItem(key));
return supervisor;
}
So, I'm trying to add to the record whenever an user clicks in a checkbox. And this is where the problem happens. Here's the function:
function checkboxClicked(idCbx) {
var idSection = $("#ContentPlaceHolder1_hdnActualField").val();
var supervisor = getObj(idSection);
console.log(typeof (supervisor)); //Returns object, everythings fine
console.log(typeof (supervisor.change)); //Returns boolean
supervisor.change = true;
var idCheck = idCbx.split("_")[2]; //I just want a part of the name
console.log(typeof(supervisor.selections)); //Prints object
console.log("Length " + supervisor.selections.size); //Undefined!
supervisor.selections.set(idCheck, true); //Error! Note: The true is just for testing purposes
setObj(idSection, supervisor);
}
What am I doing wrong? Thanks!
Please look at this example, I removed the jquery id discovery for clarity. You'll need to adapt this to meet your needs but it should get you mostly there.
const mapToJSON = (map) => [...map];
const mapFromJSON = (json) => new Map(json);
function Supervisor(id) {
this.id = id;
this.verif = null;
this.selections = new Map();
this.change = false;
this.selections.set('blah', 'hello');
}
Supervisor.from = function (data) {
const id = data.id;
const supervisor = new Supervisor(id);
supervisor.verif = data.verif;
supervisor.selections = new Map(data.selections);
return supervisor;
};
Supervisor.prototype.toJSON = function() {
return {
id: this.id,
verif: this.verif,
selections: mapToJSON(this.selections)
}
}
const expected = new Supervisor(1);
console.log(expected);
const json = JSON.stringify(expected);
const actual = Supervisor.from(JSON.parse(json));
console.log(actual);
If you cant use the spread operation in 'mapToJSON' you could loop and push.
const mapToJSON = (map) => {
const result = [];
for (let entry of map.entries()) {
result.push(entry);
}
return result;
}
Really the only thing id change is have the constructor do less, just accept values, assign with minimal fiddling, and have a factory query the dom and populate the constructor with values. Maybe something like fromDOM() or something. This will make Supervisor more flexible and easier to test.
function Supervisor(options) {
this.id = options.id;
this.verif = null;
this.selections = options.selections || new Map();
this.change = false;
}
Supervisor.fromDOM = function(id) {
const selections = new Map();
const children = $("#ContentPlaceHolder1_checkboxes_div_" + id).children();
for (var i = 0; i < children.length; i++) {
if (i % 2 == 0) {
var checkbox = children[i];
var idCheck = checkbox.id.split("_")[2];
selections.set(idCheck, false);
}
}
return new Supervisor({ id: id, selections: selections });
};
console.log(Supervisor.fromDOM(2));
You can keep going and have another method that tries to parse a Supervisor from localStorageand default to the dom based factory if the localStorage one returns null.

Pass array values as parameter to function and create json data

I have a scenario where I am passing an array of objects to a function in nodejs, but the same is failing with undefined error.
Here is what I have tried :
var object = issues.issues //json data
var outarr=[];
for(var key in object){
outarr.push(object[key].key)
}
console.log(outarr) // array is formed like this : ['a','b','c','d','e']
for(var i =0; i<outarr.length;i++){
jira.findIssue(outarr[i]) //here I am trying to pass the array objects into the loop one by one
.then(function(issue) {
var issue_number = issue.key
var ape = issue.fields.customfield_11442[0].value
var description = issue.fields.summary
var ice = issue.fields.customfield_15890[0].value
var vice = issue.fields.customfield_15891.value
var sor = issue.fields.labels
if (sor.indexOf("testcng") > -1) {
var val = 'yes'
} else {
var val = 'yes'
}
var obj = {};
obj['ape_n'] = ape;
obj['description_n'] = description;
obj['ice_n'] = ice;
obj['vice_n'] = vice;
obj['sor_n'] = val;
var out = {}
var key = item;
out[key] = [];
out[key].push(obj);
console.log(out)
} })
.catch(function(err) {
console.error(err);
});
});
What I am trying to achieve : I want to pass the array values as a parameter which is required by jira.findissue(bassically passing the issue number) one by one and which should again fetch the values and give a combine json output.
How can I pass this array values one by one in this function and also run jira.findissue in loop.
Any help will be great !! :-)
I have taken a look at the code in your question.
To be honest the code you wrote is messy and contains some simple syntax errors.
A good tip is to use a linter to avoid those mistakes.
More info about linters here: https://www.codereadability.com/what-are-javascript-linters/
To output all results in one array you have to define the array outside the scope of the loop.
I cleaned the code a bit up and use some es6 features. I don't know the context of the code but this is what I can make off it:
//map every value the key to outarr
let outarr = issues.issues.map( elm => elm.key);
//Output defined outside the scope of the loop
let output = [];
//looping outarr
outarr.forEach( el => {
jira.findIssue(el).then(issue => {
//creating the issue object
let obj = {
ape_n: issue.fields.customfield_11442[0].value,
description_n: issue.fields.summary,
ice_n: issue.fields.customfield_15890[0].value,
vice_n: issue.fields.customfield_15891.value,
sor_n: issue.fields.labels.indexOf("testcng") > -1 ? "yes" : "yes",
};
//pushing to the output
output[issue.key] = obj;
}).catch(err => {
console.log(err);
});
});
//ouputing the output
console.log(output);
Some more info about es6 features: https://webapplog.com/es6/

firebase - javascript object returning undefined

I have a firebase set up. here is the structure:
I am having trouble getting the 'newNroomID' value (that is a6QVH, a7LTN etc..).
this value will be use to compare with the other variable value.
I know that in javascript, to access the value of the object it can be done like this:
var card = { king : 'spade', jack: 'diamond', queen: 'heart' }
card.jack = 'diamond'
but it seems different story when it comes with the firebase or surely enough i am missing something. Here is my code.
var pokerRoomsJoin = firebase.database().ref(); // this is how i set it up this block of code is for reading the data only
pokerRoomsJoin.on('value', function(data){
var rID = data.val();
var keys = Object.keys(rID);
var callSet = false;
for (var i = 0 ; i < keys.length; i++) {
var indexOfKeys = keys[i];
var roomMatching = rID[indexOfKeys];
var matchID = roomMatching.newNroomID; // this does not work alwaus give me undefined
console.log('this return :' + matchID + ' WHY!')
console.log(roomMatching)
if(matchID == 'ffe12'){ // 'ffe12' is actually a dynamic value from a paramiter
callSet = true;
}
}
})
and here is the result of the console log:
strangely i am able to access it like this
var matchID = roomMatching.newNroomID // it return a6QVH and a7LTN one at a time inside the loop
only if i set up the ref to :
var pokerRoomsJoin = firebase.database().ref('room-' + roomId);
I've tried searching but seems different from the structure i have . am I having bad data structure? Save me from this misery , thanks in advance!
Let us see the code inside for loop line by line,
1. var indexOfKeys = keys[i];
now indexOfKeys will hold the key room-id
2. var roomMatching = rID[indexOfKeys];
here roomMatching will hold the object
{ 'firebasePushId': { newDealerName: 'b',
...,
}
}
Now
3. var matchID = roomMatching.newNroomID;
This of-course will be undefined because roomMatching has only one
property , firebasePushId.
To access newNroomID , you have to do something like this,
matchID = roomMatching.firebasePushKey.newNroomID .
One way to get firebasePushKeys will be using Object.keys(roomMatching).

Javascript variable is an array of objects but can't access the elements

I am using Firebase database and Javascript, and I have code that will get each question in each category. I have an object called category will contain the name, the questions, and the question count, then it will be pushed into the list of categories (questionsPerCategory). Inside the the callback function I just do console.log(questionsPerCategory). It prints the object (array) that contains the categories and questions. Now my problem is that when I do console.log(questionsPerCategory[0]) is says it's undefined, I also tried console.log(questionsPerCategory.pop()) since it's an array but it's also undefined. Why is that? Below is the code and the image of the console log. Additional note: CODE A and C are asynchronous, CODE B and D are synchronous.
this.getQuestionsForEachCategory = function(callback, questions, questionsPerCategory) {
var ref = firebase.database().ref('category');
var questionRef = firebase.database().ref('question');
console.log('get questions for each category');
// CODE A
ref.once("value", function(snapshot) {
// CODE B
snapshot.forEach(function(childSnapshot) {
var key = childSnapshot.key;
var childData = childSnapshot.val();
var category = {
category_name: childData.category_name
};
// CODE C
questionRef.orderByChild("category_name").equalTo(childData.category_name).once("value", function(questionSnapshot){
var count = 0;
var q = [];
// CODE D
questionSnapshot.forEach(function(childQuestionSnapshot) {
var questionObj = childQuestionSnapshot.val();
count++;
questions.push(questionObj.question);
q.push(questionObj.question);
});
category.questions = q;
category.questionCount = count;
questionsPerCategory.push(category);
});
});
callback(questionsPerCategory);
});
};
The callback(questionsPerCategory); should happen when all async calls are finished.
Right now the questionsPerCategory is not ready when the callback is called.
I would use Promise API to accomplish this.
Depending on the Promise library you are using, this can be accomplished in a different ways, e.g. by using bluebird it looks like you need map functionality.
Try this code:
this.getQuestionsForEachCategory = function(callback, questions) {
var ref = firebase.database().ref('category');
var questionRef = firebase.database().ref('question');
console.log('get questions for each category');
var questionsPerCategory = [];
// CODE A
ref.once("value", function(snapshot) {
// CODE B
snapshot.forEach(function(childSnapshot) {
var key = childSnapshot.key;
var childData = childSnapshot.val();
var category = {
category_name: childData.category_name
};
// CODE C
questionRef.orderByChild("category_name").equalTo(childData.category_name).once("value", function(questionSnapshot){
var count = 0;
var q = [];
// CODE D
questionSnapshot.forEach(function(childQuestionSnapshot) {
var questionObj = childQuestionSnapshot.val();
count++;
questions.push(questionObj.question);
q.push(questionObj.question);
});
category.questions = q;
category.questionCount = count;
questionsPerCategory.push(category);
});
callback(questionsPerCategory);
});
});
};

Add Relational Query Data to main JSON result

in my Angular app I'm trying to display a set of results that come from three Classes. Data is stored on Parse.com.
I can do just fine with the Pointer relation type for one-to-one (associated scores are being returned).
Problem starts when I try to include data from the Location class into my final returned JSON.
Hopefully this is just a basic notation thing I'm missing.
Thanks a lot!
Doctors
String: firstname
Pointer: score
Relation: location
Scores
Number: scoreOne
Number: scoreTwo
Locations
String: name
String: address
.controller('BrowseCtrl', function($scope) {
// Get "Doctors" and associated "Scores"
// via Pointer in Doctors Class named "score"
var query = new Parse.Query("Doctors");
query.include("score");
query.find()
.then(function(result){
var doctorsArray = new Array();
for(i in result){
var obj = result[i];
var doctorIds = obj.id;
var docFirstname = obj.get("firstname");
var mainScore = obj.get("score").get("mainScore");
doctorsArray.push({
Scores:{
DocMainScore: mainScore
},
firstname: docFirstname,
});
}
// Get Locations.
// -can be more than one per Doctor
// Class Doctors has a Relation column "location" pointing to Locations
var locationsArray = new Array();
var locationRelation = obj.relation('location');
var locationQuery = locationRelation.query();
locationQuery.find({
success: function(locations) {
for(j in locations){
var locObj = locations[j];
var locName = locObj.get("name");
console.log(locName);
}
}
})
// send data to the view
$scope.myData = doctorsArray;
console.log(doctorsArray);
});
})
What I am trying to do is get the data from Locations into the doctorsArray.
First of all, you are using obj outside the for where it's assigned. This way it'll only get location for the last doc, I'm pretty sure it's not what you wanted.
What you want must be something like this:
// inside your Doctors query result
Parse.Promise.when(
// get locations for all doctors
result.map(function(doc) {
return doc.relation('location').query().find();
})
).then(function() {
var docsLocations = arguments;
// then map each doctor
$scope.myData = result.map(function(doc, i) {
// and return an object with all properties you want
return {
Scores: {
DocMainScore: doc.get('score').get('mainScore')
},
firstname: doc.get('firstname'),
locations: docsLocations[i]
};
});
});

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