Do you need clarification about what DOM Javascript is? And why do we use DOM Javascript in Web development? Don’t worry here is the answer to all your questions.
This article will give you detailed information about what DOM Javascript is. Clearing all your doubts related to the topic and helping you out in your journey to become a web developer.
DOM JavaScript
The DOM JavaScript refers to the Document Object Model in JavaScript. It is a programming model that represents the structure of a webpage as a tree of objects. It allows developers to access, modify, and manipulate elements, attributes, and content dynamically. With DOM manipulation, developers can create interactive and responsive web pages.
This powerful feature enables developers to build dynamic web applications, providing a seamless user experience and enhancing the functionality of modern web development.
Why DOM is Required?
HTML is used to organize web pages, while JavaScript adds actions to the web pages. When a browser opens an HTML file, JavaScript can’t directly understand it. Instead, it works with the Document Object Model (DOM) that the browser creates based on the HTML.
From this, we can understand that DOM is nothing but a representation of HTML documents in a tree-like structure.
Below are some important points explaining why DOM JavaScript is essential in Web development-
- Dynamic Web Pages: The DOM allows JavaScript to manipulate the structure, content, and style of a web page dynamically. This dynamic behavior is crucial for interactive and responsive web applications.
- Accessing and Manipulating Elements: The DOM provides a way to access and manipulate elements within a web page. This function plays an important role in adding or removing elements, changing content, and responding to user interactions.
- Cross-Browser Compatibility: The DOM provides a standardized interface that web browsers use to interact with web pages. This helps in maintaining consistency and compatibility across different browsers, making it easier for developers to write code that works seamlessly across platforms.
The DOM Programming Interface
The DOM can be accessed with JavaScript and other programming languages, In DOM all the HTML objects are defined as objects and the programming interface in DOM is a collection of methods, properties, and objects that programming languages such as JavaScript use to modify the structure and content of HTML document.
DOM Document Object
The DOM document object is a method used to access elements in a web page. DOM Document object model basically serves as the entry point for accessing and manipulating the content and structure of a webpage this is because if we want to access any element in a web page we will always start by accessing the document object first.
Let us understand the methods of the Document object, learning how users interact and manipulate documents.
DOM JavaScript basically uses different methods for different works like for finding HTML elements, for changing HTML elements, and for adding and deleting HTML elements. Let us learn about each method in detail.
-
For Finding HTML Elements
Some basic methods used to find HTML Elements include-
- document.getElementById(id) – This method is used to find an element based on the element Id.
- document.getElementsByTagName(name)- This method is used to find an element based on the Tag name.
- document.getElementsByClassName(name)- This method is used to find an element by class name of an element.
-
For Changing HTML Elements
Some common methods used to change attributes and styles of HTML documents include:
- element.innerHTML– This method is used to change the inner HTML of an element.
- element.attribute– This method is used to change the attribute value of an HTML element.
- element.style.property– This method is used to change the style of an HTML element.
-
For Adding and Deleting Elements
Now we will talk about some common methods used to add and delete elements in HTML documents:
- document.createElement(element) – This method is used to create an HTML element.
- document.removeChild(element) – This method is used to remove an HTML element
- document.appendChild(element) – This method is used to add an HTML element
- document.replaceChild(new, old) – This method is used to replace an HTML element.
DOM active Element Property
The activeElement property in DOM JavaScript simply tells you which element on a webpage is currently active or focused. Suppose, if you’re filling out a form on a website and you’re typing something in a text box then the activeElement property would point to that text box because it’s where your actions are currently happening.
The basic syntax used for defining this property is: document.activeElement
Let us understand the implementation of this property with the help of a simple code given below-
<!DOCTYPE html>
<html>
<head>
<title>Digital Diary</title>
</head>
<body>
<div id=”diary” contenteditable=”true”>
Write your thoughts here…
</div>
<button onclick=”showActiveElement()”>Show Active Element</button>
<script>
function showActiveElement() {
const activeElement = document.activeElement;
alert(‘Active Element ID: ‘ + activeElement.id);
}
</script>
</body>
</html>
In this example, Imagine you have a digital diary app where you can type your daily thoughts. When you tap on the area where you write your thoughts, that area becomes the active element. You can use JavaScript to find out which part of the diary you’re typing in by checking the activeElement property.
when you click inside the “Digital Diary” area and start typing, then click the “Show Active Element” button, it will alert you with the ID of the active element.
Hope this property is now clear to you, moving on to the next we have the DOM URL property.
DOM URL Property
The URL property in DOM JavaScript is used to get or set the URL also known as the Uniform Resource Locator of the current webpage. This property basically provides access to the URL components such as the protocol, hostname, pathname, search parameters, etc.
Let us understand this property more clearly with an example given below:
<!DOCTYPE html>
<html>
<head>
<title> My Address Book </title>
</head>
<body>
<h1>Welcome to My Address Book</h1>
<p>The current URL of this page is:</p>
<p id=”currentUrl”></p>
<script>
const currentUrl = window.location.href;
document.getElementById(‘currentUrl’).textContent = currentUrl;
</script>
</body>
</html>
Let us understand the code above to get clarity on what is happening here,
So this code is basically designed to represent a simple address book. Now, when the page loads, the JavaScript will get the current URL using window.location.href. After this, the textContent property is used to display the current URL inside the <p> element.
So basically when open this file in your browser, it will display a message on the screen like: “The current URL of your page is- http://myaddressbook.html” showing you the actual URL of the page.
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FAQs On DOM Javascript
What is the DOM in JavaScript?
The DOM refers to Document Object Model in JavaScript. It is nothing but a programming interface that represents the structure of an HTML document as a tree of objects. It allows developers to interact and manipulate elements, attributes, and content on a webpage dynamically.
How do I access elements in the DOM using JavaScript?
You can access elements in the DOM Javascript using methods like “getElementById”, “getElementsByClassName” “getElementsByTagName”, etc. These methods allow you to access specific elements based on their IDs, classes, and tags
What is event handling in the DOM?
Event handling in the DOM Javascript refers to the process of capturing and responding to user interactions, such as clicks, key presses, mouse movements, form submissions, etc. We can use event listeners like “addEventListener” to attach functions that execute when a specific event occurs on an element.
How do I modify HTML content using the DOM?
You can modify HTML content using methods provided by the DOM. For example, you can change the text or HTML content using “textContent” properties, add new elements using methods like “createElement” and remove elements in the HTML using “removeChild” property.
