What is a Javascript callback?
MDN says that a callback is a function that is passed as an argument to another function. As far as I understand, it means callback is included within parentheses. This is the link. But, I once came across an article…
Can two Javascript functions call each other & send a message when done?
I have 2 functions that call each other. How to send a message when all conditions are met? My code: const func1 = async (arg) => { let table_id = result.data.internal_id; const response = await axios_Func({ graphQL query }); console.log(`${response.data.name}…
React – Properly triggering callback that represents a state change event from react component – Javascript
In an app I am building a custom range slider. I have a state that maintains the current value and also a prop that is exposes a callback triggered on change of this internal state. Below is how I am…
async / await version of https.get vs promise version vs callback version in asynchronous JavaScript programming
Why this async/await version of asynchronous program in JS doesn't give any output? async-await version: const https = require('https'); async function getDataFromServer() { try { const response = await https.get('https://jsonplaceholder.typicode.com/posts/1'); let data = ''; response.on('data', (chunk) => { data +=…
Javascript add param when calling a callback function
I want to set additional Parameters to callback function when defining it. // min Length validator function minLengthValidator(input, minLength) { console.log("Length is", input.length, "min Length is", minLength); return input.length >= minLength; } // using the callback in an validate function…
How to save result of MySql query in javascript object properties?
I have a Game class with the properties id, player1 and player2. I want to write a method to fetch data from a mySql database and set the object properties accordingly. The Object get initialized in an other file called…
Group data from JSON in callback function in Typescript
I need to write a function groupBy that groups the people in the JSON data using a function given. Below is the interface and JSON data: interface Person { name: string; yearOfBirth: number; placeOfBirth: string; } const input: Person[] =…
Flutter Dart setState o callBack tra istanze di classi diverse
Good evening everyone. I'm structuring an app on 2 columns. In the left column I would like to insert a button that updates the contents of the right column. Although keeping all the code in a single class I can…
Mongodb – mongoose code showing error of a call ack function
app.post ('/create_contact',function(req,res) { contact.create({ name :req.body.name, phone:req.body.phone },function(err,newContact) { if(err){console.log('error in creating a contact!'); return;} console.log('********',newContact); return res.redirect('back'); }); }); Errors: throw new MongooseError('Model.create() no longer accepts a callback'); ^ MongooseError: Model.create() no longer accepts a callback I tried this…
Navigator inside QuickAlert Dialog does not work – Flutter
In flutter, I have this Screen deep down in my MaterialApp's widget tree: class ItemDetailsScreen extends StatefulWidget { ItemDetailsScreen(); @override State<ItemDetailsScreen> createState() => _ItemDetailsScreenState(); } class _ItemDetailsScreenState extends State<ItemDetailsScreen> { @override Widget build(BuildContext context) { bleController.onBleStatusChange('box_is_open', context); return Scaffold(.... }…