JSFiddle - React, Tailwind, and code Playground

JavaScript

function ItemsCollection() {
	//this.someHandler = $('#some_table_id');
	this.data = [];
	var self = this;


	this.getData = function () {
		return new Promise(function (resolve, reject) {
			console.log('getting the data');
			$.get('https://jsonplaceholder.typicode.com/posts/1', function (data) {
				resolve(data);
			});
		});
	};
  
	this.prepareData = function (data) {
  	console.log('preparing the data');
		return new Promise(function (resolve, reject) {
			for (var x = 0; x < data.length; x++) {
				self.data.push(
					new Item(data[x])
				);
			}			
			resolve(self.data);
		});
	};
  
	this.updateTable = function () {
		console.log('updateing the table');

	};
}


 var mydata = new ItemsCollection();
    mydata.getData().then(
    	(data) => { 
      	return mydata.prepareData(data); 
      }) //this is done second
      .then((data) => {
        	return mydata.updateTable(data) 
       });