A Brief Introduction About Custom HTML Elements

An exciting thing about HTML is that it’s getting bigger and hyped day by day due to its incredible capabilities of creating and developing web applications in a seamless way. It is empowering developers to keep up with the latest app building technologies and let them focus more on their time creating impressive set of web applications.

HTML gives us excellent tools and components for building a document but, to be honest it’s jargon is limited to its own components, which has compelled developers to define their own elements, with their own behavior and attributes. They are known as custom elements, which are extremely helpful to get you along with your own JavaScript API. They can be used to build interfaces with components which can be used again throughout the application. They are generally bits that make up web pages. And, there are mainly two elements that are used on web pages, first, title elements that is used like this <title></title> tags, and second, body elements, which is displayed like this <body>/</body> tags.

In this blog post, you are going to learn about HTML custom elements and why it’s essential for webmasters to create them.

Let’s get started.

Before we move further, let us know first,  the dominant factors that have led to the development of web components:

  • The elements provide an effective way for developers to build their fully-functional DOM elements as per their project needs.
  • Facilitate a seamless way for creating cool markups
  • It’s meaningful, easy to use, and the best part is, it’s absolutely easy to maintain
  • Collect and organize all the elements into a single hash tag

Why It’s Crucial to Build Custom Elements?

The basic idea is whenever you create an element, it should be named as per the function for which it is being developed to perform. For example, we use ‘video’ element for  displaying videos, ‘click’ element for clicking a button, use ‘img’ to render images. Some of the elements have their own functional properties also.

They are a great way for giving developers freedom and flexibility to define elements of their own choice based on the set of properties they are entitled to display.

If created well and as soon as they are ready, they can be moved to become an active part of a fully-fledged HTML specification. This would further determine the future of the things that we are going to make.

Getting the Grips of Creating Custom Elements? 

Open the text editor, and if we write here <Jacob></Jacob> (you can use any name, whichever you may prefer), and move it to the browser and style it accordingly, and then add JavaScript controls on this tag to make them work flawlessly, but it would look just enough as a normal div.


This is new custom tag


One has to be ensured about the usage of ‘-‘ between the names because only then you can make them valid. For example, it can be presented like this <abc-elements>. Elements which do not include ‘-‘ are known as regular elements. ‘-‘ is used as a determinant factor when it comes to establish a difference between regular and valid elements. It also makes it easier for parser to distinguish and ensuring compatibilities when new tags are added to HTML. Those HTML elements which are left to register or unrecognized, are known as HTMLUnknown Element interface, on the other hand, those which are unregistered and well recognized use the HTML Element Interface. One of the coolest things that would make you fall in love with these elements is the way they render powers to developers to incorporate the methods and assign properties as per their needs, while creating per-element API for each of them.

Creating JavaScript API for Elements

To initiate this, you need to define your JavaScript custom elements that contain number of functionalities and properties for the elements. JavaScript objects can be created with a method called object.create (). When HTMLElement.prototype has been moved to this method, you can create an object as per the set of standards and methods that are already provided to HTML components. Here, we are using an example of <X-hootProto>

var XhootProto = Object.create(HTMLElement.prototype);

Now, you can define your own custom methods on this newly created object.

XhootProto.helloworld= function() {

Now, it’s time to define the API of your custom element, this can be done like this:  Object.defineProperty(). Here the first part, describes the prototype object, the second, define the property, third, describes the behavior of that property. At this point only, one can assign the default value of the property and determine whether it’s readable or writable.

Object.defineProperty(XhootProto, ‘badges’, {

value: 35,
writable : yes

Now that your API has been defined pretty clearly, it’s time to call document.registerElement(). This is the name which should be used in place of the first part, and then an object with a property name ‘prototype’, must be passed into it. Now, integrate this property into the prototype object which you created earlier.

var XHootElement = document.registerElement(‘x-hoot’,  {
prototype: XhootProto

After the completion of registration process, create a new instant for the element and add it to the page.

var xHoot= new XhootElement();

The methods and attributes which you assigned earlier can be treated just like any other HTML element.

var badges = xhoot.badges;


Custom elements give developers an ability to extend the powers and abilities of the web platform to give wings to their development endeavors. Being an active part of a web components suite, they harmonize with other technologies like Shadow DOM and HTML template, thus helping developers to create exciting and dynamic applications.   

Author Bio :

Amy Brown is a web developer by profession, a writer by hobby and works for WordPrax Ltd.,  a  WordPress theme customization service company. She loves sharing information regarding WordPress customization tips & tricks.


Joe Granados the author

Joe Granados is the owner of WebDevTuts. He is also a web designer & developer who loves to design and develop websites. If you're looking for him you can find him via @webdevtuts

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