Dynamic HTML (DHTML) is a combination of technologies used to create interactive and dynamic web content. It’s not a standalone standard or programming language but rather a collection of techniques and tools that work together. DHTML enables websites to update content dynamically and provide interactivity without reloading the entire page.
HTML (Hypertext Markup Language)
Provides the basic structure of the webpage.
CSS (Cascading Style Sheets)
Controls the appearance and layout of the webpage. CSS can be dynamically altered to create effects like hover states or style changes.
JavaScript
Adds interactivity and dynamic behavior, such as updating content without a page reload.
DOM (Document Object Model)
A programming interface that allows access to and manipulation of the webpage’s structure. JavaScript interacts with the DOM to change content or add new elements.
Here’s a simple example of a button changing text dynamically:
<!DOCTYPE html>
<html>
<head>
<style>
#text {
color: blue;
font-size: 20px;
}
</style>
<script>
function changeText() {
document.getElementById("text").innerHTML = "Text changed!";
document.getElementById("text").style.color = "red";
}
</script>
</head>
<body>
<p id="text">Original text</p>
<button onclick="changeText()">Click me</button>
</body>
</html>
Nowadays, DHTML has been largely replaced by modern techniques like AJAX and frameworks (e.g., React, Vue.js). However, it was a crucial step in the evolution of interactive web applications.
The Document Object Model (DOM) is a standardized interface provided by web browsers to represent and programmatically manipulate structured documents, especially HTML and XML documents. It describes the hierarchical structure of a document as a tree, where each node represents an element, attribute, or text.
Tree Structure:
<html>
element, with child nodes such as <head>
, <body>
, <div>
, <p>
, etc.Object-Oriented Representation:
Interactivity:
<p>
element or insert a new <div>
.Platform and Language Agnostic:
1. Accessing an Element:
let element = document.getElementById("myElement");
2. Changing Content:
element.textContent = "New Text";
3. Adding a New Element:
let newNode = document.createElement("div");
document.body.appendChild(newNode);
The DOM is defined and maintained by the W3C (World Wide Web Consortium) standards and is constantly updated to support modern web technologies.
HTML stands for "Hypertext Markup Language" and is a markup language used to structure content on the web. It serves as a foundation for web development, describing and organizing the content of a web page. HTML uses tags or markup to identify and structure different elements on a webpage.
A basic HTML document consists of HTML tags marking the beginning and end of elements. Here's an example of the basic structure of an HTML document:
<!DOCTYPE html>
<html>
<head>
<title>Page Title</title>
</head>
<body>
<h1>Heading 1</h1>
<p>This is a paragraph.</p>
<!-- More HTML elements here -->
</body>
</html>
Here are some basic HTML elements:
<html>
: The root element that wraps around the entire HTML content.<head>
: Contains meta-information about the HTML document, such as the page title, references to CSS files, etc.<title>
: Defines the title of the webpage displayed in the browser tab.<body>
: Contains the actual content of the webpage, such as text, images, links, etc.<h1>
, <h2>
, <h3>
, ..., <h6>
: Headings of different hierarchy levels.<p>
: A paragraph.<!-- comment -->
.HTML is often used in conjunction with CSS (Cascading Style Sheets) and JavaScript to not only structure content but also to style and provide interactivity to web pages.