How Does The DOM Interact With HTML Elements

The Document Object Model, or DOM, is a programming interface for web documents. It represents the page so that programs can change the document structure, style, and content. The DOM represents the document as nodes and objects; that way, programming languages can interact with the page.

When a web page is loaded, the browser creates a Document Object Model of the page, which serves as an internal representation of the HTML elements. The DOM organizes the HTML elements in a hierarchical structure, where each element is a node. The nodes can be accessed and manipulated using programming languages such as JavaScript.

In this blog post, we will explore how does the DOM interact with HTML elements and how developers can manipulate the DOM using JavaScript.

How does the DOM interact with HTML elements?

As mentioned earlier, the DOM organizes HTML elements in a hierarchical structure, where each element is a node. The root node is the document object, which represents the entire HTML page. From there, each HTML element is a child node of the document object, and the child nodes can have their children, and so on, forming a tree-like structure.

The DOM interacts with HTML elements by creating objects that represent each node in the tree structure. These objects expose methods and properties that allow developers to manipulate the HTML elements.

For example, suppose we have an HTML page with a div element as follows:

<!DOCTYPE html>
<html>
  <head>
    <title>DOM Example</title>
  </head>
  <body>
    <div id="myDiv">Hello, World!</div>
  </body>
</html>

To interact with the div element using the DOM, we can use JavaScript to get a reference to the div object, as shown below:

var myDiv = document.getElementById("myDiv");

The document object represents the entire HTML page, and the getElementById method is used to get a reference to the div element with an id of “myDiv.” Once we have a reference to the div object, we can manipulate it using its properties and methods.

Manipulating HTML elements using the DOM

Manipulating HTML elements using the DOM is essential in web development. With the DOM, developers can create dynamic web pages that respond to user actions, such as clicking a button or submitting a form.

Let’s look at some common ways to manipulate HTML elements using the DOM.

Changing an HTML element’s text

To change the text of an HTML element using the DOM, we can use the innerHTML property. The innerHTML property gets or sets the HTML content within an element.

var myDiv = document.getElementById("myDiv"); 
myDiv.innerHTML = "Goodbye, World!";

In the code above, we first get a reference to the div element with an id of “myDiv” using the getElementById method. We then use the innerHTML property to set the content of the div element to “Goodbye, World!”

Changing an HTML element’s style

We can also use the DOM to change an HTML element’s style. Each HTML element has a style property that represents its inline style attribute.

var myDiv = document.getElementById("myDiv"); 
myDiv.style.backgroundColor = "blue";

In the code above, we first get a reference to the div element with an id of “myDiv” using the getElementById method. We then use the style property to change the background color of the div element to blue.

Adding and removing HTML elements

We can also add and remove HTML elements using the DOM. To add an HTML element, we can create the element using the createElement method and append it to an existing element using the appendChild method.

var myDiv = document.getElementById("myDiv"); 
var newParagraph = document.createElement("p"); 
newParagraph.innerHTML = "This is a new paragraph";
myDiv.appendChild(newParagraph);

In the code above, we first get a reference to the div element with an id of “myDiv” using the getElementById method. We then create a new paragraph element using the createElement method and set its innerHTML property to “This is a new paragraph.” Finally, we append the new paragraph element to the div element using the appendChild method.

To remove an HTML element, we can use the removeChild method.

var myDiv = document.getElementById("myDiv"); 
var paragraphToRemove = myDiv.getElementsByTagName("p")[0]; 
myDiv.removeChild(paragraphToRemove);

In the code above, we first get a reference to the div element with an id of “myDiv” using the getElementById method. We then get a reference to the first paragraph element within the div element using the getElementsByTagName method. Finally, we remove the paragraph element using the removeChild method.

Conclusion

The Document Object Model, or DOM, is a powerful tool for manipulating HTML elements in web development. By organizing HTML elements in a hierarchical structure, the DOM allows developers to access and manipulate each element using programming languages such as JavaScript.

In this blog post, we explored how does the DOM interact with HTML elements and how developers can manipulate the DOM using JavaScript. We looked at some common ways to manipulate HTML elements using the DOM, such as changing an HTML element’s text, changing an HTML element’s style, and adding and removing HTML elements.

As you continue to learn web development, keep in mind the power of the DOM and how it can be used to create dynamic web pages that respond to user actions.

If you enjoyed this article, check out our latest post on The Advantages and Disadvantages of Using CSS Frameworks. As always if you have any questions or concerns, feel free to contact us.