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nodejs filtering an array of objects where the filtering is partially done in an async function

I've read many similar questions and have tried a bunch of code. Unfortunately, I'm not getting my code to run :-(
So, the situation is as follows: In a route of a node.js server, I have to respond with a filtered array of Objects. Unfortunately, whatever I do, I always get an empty array [] back. The filter is a bit tricky in my opinion, as it consists of a string comparison AND an async call to a library function. With the console output, I can clearly see that the correct element is found, but at the same time I see that I've already received the object...
Here is some code that exemplifies my challenge:
let testArray = [
{
id: 'stringId1',
data: {
someDoc: {
moreContent: 'Some random content',
type: 'noInterest'
}
}
},
{
id: 'stringId2',
data: {
someDoc: {
moreContent: 'Some random content',
type: 'ofInterest'
}
}
},
{
id: 'stringId3',
data: {
someDoc: {
moreContent: 'Some random content',
type: 'ofInterest'
}
}
}
]
// code from a library. Can't take an influence in it.
async function booleanWhenGood(id) {
if (id in some Object) {
return { myBoolean: true };
} else {
return { myBoolean: false };
}
}
// Should return only elements with type 'ofInterest' and that the function booleanWhenGood is true
router.get('/', function(res,req) {
tryOne(testArray).then(tryOneResult =>{
console.log('tryOneResult', tryOneResult);
});
tryTwo(testArray).then(tryTwoResult => {
console.log("tryTwoResult ", tryTwoResult);
});
result = [];
for (const [idx, item] of testArray.entries() ) {
console.log(idx);
if (item.data.someDoc.type === "ofInterest") {
smt.find(item.id).then(element => {
if(element.found) {
result.push(item.id);
console.log("ID is true: ", item.id);
}
});
}
if (idx === testArray.length-1) {
// Always returns []
console.log(result);
res.send(result);
}
}
})
// A helper function I wrote that I use in the things I've tried
async function myComputeBoolean(inputId, inputBoolean) {
let result = await booleanWhenGood(inputId)
if (result.myBoolean) {
console.log("ID is true: ", inputId);
}
return (result.myBoolean && inputBoolean);
}
// A few things I've tried so far:
async function tryOne(myArray) {
let myTmpArray = []
Promise.all(myArray.filter(item => {
console.log("item ", item.id);
myComputeBoolean(item.id, item.data.someDoc.type === "ofInterest")
.then(myBResult => {
console.log("boolean result", myBResult)
if (myBResult) {
tmpjsdlf.push(item.id);
return true;
}
})
})).then(returnOfPromise => {
// Always returns [];
console.log("returnOfPromise", myTmpArray);
});
// Always returns []
return(myTmpArray);
}
async function tryTwo(myArray) {
let myTmpArray = [];
myArray.forEach(item => {
console.log("item ", item.id);
myCompuBoolean(item.id, item.data.someDoc.type === "ofInterest")
.then(myBResult => {
console.log("boolean result", myBResult)
if (myBResult) {
myTmpArray.push(item.did);
}
})
});
Promise.all(myTmpArray).then(promiseResult => {
return myTmpArray;
});
}
Asynchronous programming is really tough for me in this situation... Can you help me get it running?

I didn't inspect your attempts that closely, but I believe you are experiencing some race conditions (you print return and print the array before the promises resolve).
However you can alwayd use a regular for loop to filter iterables. Like this:
let testArray = [
{
id: 'stringId1',
data: {
someDoc: {
moreContent: 'Some random content',
type: 'noInterest'
}
}
},
{
id: 'stringId2',
data: {
someDoc: {
moreContent: 'Some random content',
type: 'ofInterest'
}
}
},
{
id: 'stringId3',
data: {
someDoc: {
moreContent: 'Some random content',
type: 'ofInterest'
}
}
}
]
async function booleanWhenGood(id) {
if (id in { 'stringId1': 1, 'stringId2': 1 }) { // mock object
return { myBoolean: true };
} else {
return { myBoolean: false };
}
}
async function main() {
let filtered = []
for (item of testArray)
if ((await booleanWhenGood(item.id)).myBoolean && item.data.someDoc.type === 'ofInterest')
filtered.push(item)
console.log('filtered :>> ', filtered);
}
main()

how to print all students name which have percentage more than 70% in javascript?

I am using json-rule-engine .
https://www.npmjs.com/package/json-rules-engine
I am having a student list which have name and their percentage, Also I have business rule the percentage should be greater thank or equal to than 70 . so I want to print all students name those have percentage more than 70
here is my code
https://repl.it/repls/AlienatedLostEntropy#index.js
student list
const students = [
{
name:"naveen",
percentage:70
},
{
name:"rajat",
percentage:50
},
{
name:"ravi",
percentage:75
},
{
name:"kaushal",
percentage:64
},
{
name:"piush",
percentage:89
}
]
rule
engine.addRule({
conditions: {
all: [
{
fact: "percentage",
operator: "greaterThanInclusive",
value: 70
}
]
},
onSuccess(){
console.log('on success called')
},
onFailure(){
console.log('on failure called')
},
event: {
type: "message",
params: {
data: "hello-world!"
}
}
});
code
https://repl.it/repls/AlienatedLostEntropy#index.js
any update

The json-rules-engine module takes data in a different format. In your Repl.it you have not defined any facts.
Facts should be:
let facts = [
{
name:"naveen",
percentage:70
},
[...]
Also, the module itself doesn't seem to process an array of facts. You have to adapt it to achieve this. This can be done with:
facts.forEach((fact) => {
engine
.run(fact)
[...]
Finally, the student data is found inside the almanac. You can get these values with: results.almanac.factMap.get('[name|percentage|age|school|etc]').value
Here is the updated Repl.it: https://repl.it/#adelriosantiago/json-rules-example

I might have submitted a completely unrelated answer, but here goes. Since the students object is an array, you could just loop through it and then use an if else statement.
for (let i = 0; i < students.length; i++) {
if (students[i].percentage >= 70) {
console.log(students[i].name);
}
}
Sorry if this is incorrect!

Here is a working example.
Counting success and failed cases
const { Engine } = require("json-rules-engine");
let engine = new Engine();
const students = [
{
name:"naveen",
percentage:70
},
{
name:"rajat",
percentage:50
},
{
name:"ravi",
percentage:75
},
{
name:"kaushal",
percentage:64
},
{
name:"piush",
percentage:89
}
]
engine.addRule({
conditions: {
all: [{
fact: 'percentage',
operator: 'greaterThanInclusive',
value: 70
}]
},
event: { type: 'procedure_result'}
})
let result = {success_count : 0 , failed_count : 0}
engine.on('success', () => result.success_count++)
.on('failure', () => result.failed_count++)
const getResults = function(){
return new Promise((resolve, reject) => {
students.forEach(fact => {
return engine.run(fact)
.then(() => resolve())
})
})
}
getResults().then(() => console.log(result));

how to get data inside json object inside object?

i try to get some track_list data inside object JSON using Musixmatch API
here is my code
"body": {
"track_list": [
{
"track": {
"track_id": 194169151,
"track_name": "Blinding Lights",
"track_name_translation_list": [],
"track_rating": 100,
"commontrack_id": 104185748,
"instrumental": 0,
"explicit": 0,
"has_lyrics": 1,
"has_subtitles": 1,
"has_richsync": 1,
"num_favourite": 3237,
"album_id": 37216011,
"album_name": "After Hours",
"artist_id": 13937035,
"artist_name": "The Weeknd",
"track_share_url": "https://www.musixmatch.com/lyrics/The-Weeknd-3/Blinding-Lights?utm_source=application&utm_campaign=api&utm_medium=rickyreza%3A1409619798940",
"track_edit_url": "https://www.musixmatch.com/lyrics/The-Weeknd-3/Blinding-Lights/edit?utm_source=application&utm_campaign=api&utm_medium=rickyreza%3A1409619798940",
"restricted": 0,
"updated_time": "2020-04-10T08:31:57Z",
"primary_genres": {
"music_genre_list": [
{
"music_genre": {
"music_genre_id": 7,
"music_genre_parent_id": 34,
"music_genre_name": "Electronic",
"music_genre_name_extended": "Electronic",
"music_genre_vanity": "Electronic"
}
}
]
}
}
},
i just want to check if i can geat the data inside a track by doing lyric.album_name. and tried to get the album and i got this kind of things album_name as undefined. here is my main.js
main.js
function main() {
// initialize the data
const baseUrl = "https://api.musixmatch.com/ws/1.1";
const apiKey = "78fa4727ab9c4495d4fc07dae75f775b";
const chartTrack = "chart.tracks.get?chart_name=top&page=1&page_size=5&country=jp&f_has_lyrics=1"
const getLirik = () => {
fetch(`${baseUrl}/${chartTrack}&apikey=${apiKey}`)
.then(response => {
return response.json();
})
.then(responseJson => {
// console.log(responseJson);
// trackList.track_list = responseJson.message.body.track_list
console.log(responseJson.message.body.track_list.track);
// console.log(responseJson.message.body.track_list.track.album_name);
renderAllData(responseJson.message.body.track_list);
})
.catch(error => {
console.log(error);
})
}
/*
for making a new html DOM
*/
const renderAllData = (lyrics) => {
const lirikElement = document.querySelector("#popularLyrics");
lirikElement.innerHTML = "";
lyrics.forEach(lyric => {
lirikElement.innerHTML += `
<div>${lyric.album_name}</div>
`
})
}
getLirik();
}
export default main;
How do i can get all thos track_name and stuff inside track?

You forgot the property .track in your lyrics object. Try this
...
<div>${lyric.track.album_name}</div>

i checked the api call https://api.musixmatch.com/ws/1.1/chart.tracks.get?chart_name=top&page=1&page_size=5&country=jp&f_has_lyrics=1&apikey=78fa4727ab9c4495d4fc07dae75f775b the tracklist returns an Array of objects, where each object has only one key track
something like this track_list = [{track:{}},{track:{}}]
use ${lyric.track.album_name} it should work

you forgot one property, but you can do less nesting using destructuring in the function, this is a litle modification of your code:
const renderAllData = (trackList) => {
const lirikElement = document.querySelector("#popularLyrics");
lirikElement.innerHTML = "";
trackList.forEach(({ track }) => {
lirikElement.innerHTML += `
<div>${track.album_name}</div>
`;
});
};
renderAllData(data.body.track_list);

Edit query string parameter on retry

I've got the following code structure:
$.ajax({
type:"GET",
url:"http://example.com",
data:{
final:false
},
retry: {
attempt: 1,
limit: 3,
delay: 2000
},
success((data) => {
console.log("yay!");
}),
error((error) => {
if (this.retry.attempt++ <= this.retry.limit) {
var self = this;
if (self.retry.attempt > self.retry.limit) {
self.data.final = true;
}
setTimeout(() => {$.ajax(self)}, this.retry.delay);
}
})
});
The problem is that, when the request is called the first time, the data parameter gets erased, and its values appended to the url as a query string. So data no longer exists. The object that gets passed into the retry call is:
{
type:"GET",
url:"http://example.com?final=false",
retry: {
attempt: 2,
limit: 3,
delay: 2000
},
success((data) => {
//...
}),
error((error) => {
//...
}
}
How do I edit the final parameter of the request for the last retry?

You could try changing URL to "http://example.com?final=false" or "http://example.com?final="+false if false is a variable

try defining your request outside the ajax call:
const request = {
type:"GET",
url:"http://example.com",
data:{
final:false
}
};
$.ajax({...request, ...{
retry: {
attempt: 1,
limit: 3,
delay: 2000
},
success((data) => {
console.log("yay!");
}),
error((error) => {
if (this.retry.attempt++ <= this.retry.limit) {
const retryRequest = {...request, ...this};
if (this.retry.attempt > this.retry.limit) {
retryRequest.data.final = true;
}
setTimeout(() => {$.ajax(retryRequest)}, this.retry.delay);
}
})
});
alternatively, if you're only dealing with the one flag that only needs to be set on the last attempt:
$.ajax({
type:"GET",
url:"http://example.com",
retry: {
attempt: 1,
limit: 3,
delay: 2000
},
success((data) => {
console.log("yay!");
}),
error((error) => {
if (this.retry.attempt++ <= this.retry.limit) {
var self = this;
if (self.retry.attempt > self.retry.limit) {
self.data = {final: true};
}
setTimeout(() => {$.ajax(self)}, this.retry.delay);
}
})
});
also, fat arrow functions don't have local context, so your error function doesn't need to use self, i.e. this will work:
error((error) => {
if (this.retry.attempt++ <= this.retry.limit) {
if (this.retry.attempt > this.retry.limit) {
this.data = {final: true};
}
setTimeout(() => {$.ajax(this)}, this.retry.delay);
}
})

Filter by list of tests

What is the concise, functionally-oriented way of filtering a list of URLs where each item has to pass a list of tests? If the URL matches any of the tests, it should be filtered out.
I currently have:
var _ = require("underscore");
const anchors = [
{href:"https://example.org/contact"},
{href:"https://example.org/faq"},
{href:"https://example.org/contact"},
{href:"https://example.org/uploads/image-1024x1018.jpg"},
{href:"https://example.org/wp-json/oembed/1.0/embed?url=example"},
{href:"https://example.org/author/pm"},
{href:"https://example.org/wp/wp-login.php?action=lostpassword"},
{href:"https://example.org/wp/wp-login.php"},
{href:"https://example.org/feed"},
];
const tests = [
/\/wp\//,
/\/wp-json\//,
/\.jpg$/,
/\.png$/,
/\.gif$/,
]
function testAll(testString){
let pass = true;
_.each(tests, t => {
if(t.test(testString)) pass = false;
});
return pass;
}
console.log(anchors.map(anchor => {
return anchor.href;
}).filter(anchor => {
return testAll(anchor);
}));
But I suspect testAll can be done in a more concise way.

The solution I was looking for is actually some instead of every, because I actually need to reject the URL if it matches any of the tests:
console.log(anchors.map(anchor => {
return anchor.href;
}).filter(anchor => {
// return testAll(anchor);
return !_.some(tests, t => {
return t.test(anchor);
})
}));

You can use Array#every()
function testAll(testString){
return tests.every(reg => reg.test(testString));
}

You could work with Array#some and take the negated result of the checks for filtering.
var anchors = [{ href:"https://example.org/contact" }, { href:"https://example.org/faq" }, { href:"https://example.org/contact" }, { href:"https://example.org/uploads/image-1024x1018.jpg" }, { href:"https://example.org/wp-json/oembed/1.0/embed?url=example" }, { href:"https://example.org/author/pm" }, { href:"https://example.org/wp/wp-login.php?action=lostpassword" }, { href:"https://example.org/wp/wp-login.php" }, { href:"https://example.org/feed" }],
tests = [/\/wp\//, /\/wp-json\//, /\.jpg$/, /\.png$/, /\.gif$/],
result = anchors.filter(({ href }) => !tests.some(t => t.test(href)));
console.log(result);