Wissam Muneer

Wissam Muneer

1598933748

Understanding and handling the DOM

In this article, you will learn what the document object model (DOM) is, how it is structured, how to query and handle it.

The DOM is an extremely important concept in web development and, I venture to say, every one programming for the web (especially frontend developers) should know what it is and how it can be handled. And this is what this article is about. Have a good read!

What is the DOM?

In order to create a web page, the minimum you need is an HTML file. For, example, this is a very simple page:

<!DOCTYPE html>
<html>
<head>
  <title>A very basic page</title>
</head>
<body>
  <p>This is a very basic page.</p>
</body>
</html>

If you save the above code to an HTML file (e.g. index.html_),_ and open it in a browser, this is what is rendered:

And if you inspect the page, this is what you will see:

Well, as you can see, it shows exactly the same markup from the HTML file that we’ve created.

Changing the page dynamically

Now, open your browser console and run the following code:

const newParagraph = document.createElement('p');
newParagraph.innerText = 'And this is a dynamically created paragraph';
document.body.appendChild(newParagraph);

#web-development #javascript #react #developer

What is GEEK

Buddha Community

Understanding and handling the DOM

What is DOM, Shadow DOM and Virtual DOM?

In this lesson, we learn about the Document Object Model. We learn what the DOM, Shadow DOM, and Virtual DOM are and how they work. We also look at some of the practical examples to understand them better.

#dom #shadow dom #virtual dom

Kaley  Koelpin

Kaley Koelpin

1626044160

ReactJS Tutorials in Hindi: What is DOM? DOM vs Virtual DOM Part-4

Javascript me DOM (Document Object Model) Kaise Work Karta hai

Node js, express js, and MongoDB complete tutorials playlist:
https://www.youtube.com/watch?v=Qwow9xWCHc4&list=PLUVqY59GNZQNCk_D9VW_zNh60WuQIzo3K

Follow Tutorials website:

https://www.facebook.com/tutorialswebsite
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https://twitter.com/techwebsitetrix
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ReactJS Tutorials in Hindi | Introduction | Part-1
https://youtu.be/ItGluNVKWlk

Node.js Tutorials for beginners in hindi | Setup Environment to run node js code | Part-2
https://youtu.be/OrE3JtL0gak

ReactJS Tutorials in Hindi | Environment Setup using NPM or NPX | Part-3
https://youtu.be/NPXf-QbHTH4

#dom #virtual dom #reactjs #reactjsforbeginners

Understanding DOM | Getting Deep into DOM | Document Object Model

JavaScript DOM Crash Course
Topics covered in this video :
➡️ Creating Element
➡️ Accessing Element
➡️ Using Property of Element
➡️ CSS Manipulation of Element
➡️ Using Attribute to invoke Property right way
➡️ Dynamically Adding Elements to DOM
➡️ Accessing Element using CSSOM Selector (ie querySelector)

This crash course focuses on the DOM WITHOUT JQUERY. In this part we will talk about what the JavaScript DOM (Document Object Model) is and we will look at the different selectors like

➡️ document.getElementById()
➡️ document.getElementsByClassName()
➡️ document.getElementsByTagName()
➡️ document.querySelector()
➡️ document.querySelectorAll()

We will also look at how to change content and styles via these selectors
Element object represents an HTML element.
Element is the most general base class from which all element objects (i.e. objects that represent elements) in a Document inherit.
It only has methods and properties common to all kinds of elements

Abbreviation : Document Object Model (DOM)
JavaScript DOM Tutorial
The DOM is a programming API for HTML and XML documents .

It defines the logical structure of documents and the way a document is accessed and manipulated . and this logical structure can be expressed as tree

What is DOM
DOM stands for Document Object Model. When a browser loads a web page, the browser creates a Document Object Model of that page.

In simple terms you can think of the DOM as an application programming interface (API) for HTML, and we can use programming languages like JavaScript, or JavaScript frameworks like Angular to access and manipulate the HTML using their corresponding DOM objects.

In other words DOM contains the HTML elements as objects, their properties, methods and events and it is a standard for accessing, modifying, adding or deleting HTML elements.

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#javascript #dom #documentobjectmodel #angular #react #vue

Arvel  Miller

Arvel Miller

1601290740

Understanding React Rendering

Rendering is the most important procedure that a programmer has to manage in frontend development. In React, the render() method is the only required method in a class component, and is responsible for describing the view to be rendered to the browser window. Coupled with the clever way that React operates around its virtual DOM concept, there are certain subtleties in how this method works, and understanding them will greatly benefit any aspiring React developer.

Throughout this writing, I will reference this codepen for a demonstration of discussed behaviors.

1. render() 101

First of all, render() is not user callable. It is part of the React component lifecycle and is called by React at various app stages, generally when the React component is first instantiated, or when there is a new update to the component state. Render does not take any arguments, and returns a JSX.Element which contains the view hierarchy of the current component. This view hierarchy will later be translated into HTML and displayed in the browser window.

As mentioned before, render() is not user callable as it is an event that happens in the component’s lifecycle. With that said, if it is absolutely necessary to manually render the view, you can instead call the built-in class method forceUpdate(). Keep in mind that this is considered an  anti-pattern . If you were designing sensible React components, its state and props changes should naturally control the render process, and you should never feel the need to make a manual call.

Within the lifecycle, these are the scenarios where render is called:

  • After the React component is first instantiated, following the constructor() call.
  • After an update to the component’s props
  • After a setState() call

If you have the Codepen opened at this point, before anything is rendered you will see 2 alert messages from the browser: “render() is called in Parent component!”, and “render() is called in Child component!”. These messages are invoked from the corresponding render() methods of the example’s parent and child component. They serve to introduce the first case of render() invocation: when the component is first instantiated.

Once the set of alerts is dismissed, a very simple UI will render:

Example UI

#javascript #node #react #render #function #method #dom #virtual dom

Emile  Funk

Emile Funk

1591341060

Here is why appendChild moves a DOM node between parents

Here is why appendChild moves a DOM node between parents
A light introduction into DOM fundamentals through an insightful quiz. You’ll learn how HTML is transforms into JavaScript objects to eventually become part of the Document tree.

#javascript #dom-manipulation #js #dom #appendchild