Reactive Web Programming Using Rum

Many websites allow users to interact with web pages. Users can click, drag, and sort elements. These pages are dynamic – they respond to user actions. A programming page that reacts to user interactions is called reactive programming.

HTML provides a structure of elements on a page. The Document Object Model (DOM) is a representation of HTML in JavaScript. JavaScript allows us to operate on DOM elements that are finally displayed as HTML elements on a web page.

One way to make a page react to user actions is to render (display) that whole page again. Rendering a whole page consumes computer resources. If only a small part of the page needs re-rendering, we waste precious resources re-rendering the entire page. Fortunately for us, there is a solution that allows us to re-render only the parts of a page that have changed.

React.js is a JavaScript library that supports reactive programming. The basic block of React.js is a component...