Create custom html tags

HTML provides a set of predefined elements, like

, , , etc., for creating web pages. However, in certain cases, you may want to create your own custom tags to provide a more specific semantic meaning to your content. Custom tags can make your code more maintainable and readable. This can be done through the creation of custom elements and web components.

Creating custom elements in HTML is a way to define your own custom tags that can be used in your HTML documents. This can be useful for creating reusable components or for adding functionality that is not available in standard HTML tags.

The CustomElementRegistry interface provides methods for registering and defining custom elements. Here’s an example of how to define a custom element:

class MyElement extends HTMLElement  constructor()  super(); // Initialize element > > customElements.define('my-element', MyElement);

In this example, we define a custom element called my-element that extends the HTMLElement class. The constructor method is called when the element is created, and can be used to initialize the element.

Once the custom element is defined, it can be used in HTML like any other element:

You can also add attributes and properties to your custom element:

class MyElement extends HTMLElement  static get observedAttributes()  return ['name']; > constructor()  super(); this._name = ''; > get name()  return this._name; > set name(value)  this._name = value; this.setAttribute('name', value); > attributeChangedCallback(name, oldValue, newValue)  if (name === 'name')  this._name = newValue; > > > customElements.define('my-element', MyElement);

In this example, we add a name attribute to our custom element, and define a getter and setter for a name property. We also define an observedAttributes static method that returns an array of attribute names to observe. The attributeChangedCallback method is called when an observed attribute is changed.

You can also add methods to your custom element:

class MyElement extends HTMLElement  constructor()  super(); > sayHello()  console.log('Hello!'); > > customElements.define('my-element', MyElement);

In this example, we add a sayHello method to our custom element that logs «Hello!» to the console.

Overall, creating custom elements in HTML using the CustomElementRegistry interface provides a powerful way to extend the functionality of HTML and create reusable components.

Method 2: Using Templates and Shadow DOM

Creating custom HTML tags can be useful for creating reusable components in your web pages. One way to do this is by using Templates and Shadow DOM. In this tutorial, we will go through the steps of creating a custom tag using Templates and Shadow DOM.

Step 1: Define the Template

First, we need to define the template for our custom tag. We can do this by creating a element and giving it an id attribute. In this example, we will create a template for a custom button tag.

template id="custom-button"> style> /* Styles for our custom button */ button  background-color: blue; color: white; border: none; padding: 10px; border-radius: 5px; cursor: pointer; > style> button>slot>slot>button> template>

In this template, we have defined some basic styles for our button, and included a element where the content for the button will be inserted.

Step 2: Create the Custom Element

Next, we need to create the custom element using the customElements.define() method. We will give our custom element a name and specify the class that will define its behavior.

class CustomButton extends HTMLElement  constructor()  super(); const template = document.getElementById('custom-button').content; const shadowRoot = this.attachShadow( mode: 'open' >); shadowRoot.appendChild(template.cloneNode(true)); > > customElements.define('custom-button', CustomButton);

In this code, we have defined a class CustomButton that extends HTMLElement . In the constructor for this class, we get the template we defined earlier and attach a shadow root to our custom element. We then append a clone of the template to the shadow root.

Step 3: Use the Custom Element

Now that we have defined our custom element, we can use it in our HTML like any other element.

custom-button>Click me!custom-button>

When this code is rendered, it will create a button with the styles defined in our template, and the text «Click me!» inside the button.

Method 3: Using JavaScript Libraries

To create custom HTML tags in HTML, you can use JavaScript libraries like Polymer, SkateJS, and X-Tag. In this tutorial, we will use Polymer to create a custom HTML tag.

Step 1: Install Polymer

To use Polymer, you need to install it first. You can install Polymer using npm or Bower.

Step 2: Create a new Polymer element

To create a new Polymer element, you need to create a new HTML file and define your custom tag in it. For example, let’s create a custom tag called my-element .

 dom-module id="my-element"> template> h1>Hello World!h1> template> script> Polymer( is: 'my-element' >); script> dom-module>

Step 3: Import the Polymer element

Once you have created your custom element, you can import it into your HTML file using the link tag.

 DOCTYPE html> html> head> meta charset="UTF-8"> title>My Custom Elementtitle> script src="bower_components/webcomponentsjs/webcomponents-lite.js"> script> link rel="import" href="my-element.html"> head> body> my-element>my-element> body> html>

Step 4: Use the custom element

Now that you have imported your custom element, you can use it in your HTML file by simply using the tag name you defined in the dom-module .

This will render the content of your custom element, which in this case is a simple h1 tag that says «Hello World!».

Источник

How to Create Custom Tags For Html

I ran your code and it worked just fine with the constructor , but you could try connectedCallback instead. This method gets called any time an element is added to the document.

Make sure your script runs in the of the document, before your is executed. HTML/scripts run top-to-bottom. Your element needs to be registered before it is rendered.

Update: Please refer to the «Custom elements» — JavaScript.info article that was linked by Martin Braun for a better understanding. The official MDN documentation can be viewed here: «Using custom elements» — MDN.

class MyTrophy extends HTMLElement connectedCallback() const rarity = this.getAttribute('rarity'); 
console.log(`Rarity: $`); 
>
>

customElements.define('my-trophy', MyTrophy);

my-trophy font-size: 3em;
>

my-trophy[rarity="silver"] color: #777;
>

Create custom tags/attributes using JavaScript

Why yes, yes you can. In fact, they’re a stable part of the web components standard.

Custom Elements is a capability for creating your own custom HTML
elements. They can have their own scripted behavior and CSS styling.
They are a part of web components, but can also be used by themselves.

It may be unclear as to why the new custom elements capability was
created, as it was already possible to create a tag name like
and style it with CSS, then use scripting to attach behaviors to it.
An advantage that custom elements have are their lifecycle reactions,
which allow attaching behaviors to different parts of the new
element’s «lifecycle.» For example, a certain behavior can be attached
for when the element is inserted into the DOM («connected»), and a
different behavior when it is removed from the DOM («disconnected»),
or when its attributes change.

Example

// Create a class for the elementclass XProduct extends HTMLElement < constructor() < // Always call super first in constructor super();
// Create a shadow root var shadow = this.attachShadow(); 
// Create a standard img element and set its attributes. var img = document.createElement('img'); img.alt = this.getAttribute('data-name'); img.src = this.getAttribute('data-img'); img.width = '150'; img.height = '150'; img.className = 'product-img'; 
// Add the image to the shadow root. shadow.appendChild(img); 
// Add an event listener to the image. img.addEventListener('click', () => < window.location = this.getAttribute('data-url'); >); 
// Create a link to the product. var link = document.createElement('a'); link.innerText = this.getAttribute('data-name'); link.href = this.getAttribute('data-url'); link.className = 'product-name'; 
// Add the link to the shadow root. shadow.appendChild(link); >>
// Define the new elementcustomElements.define('x-product', XProduct);

body < background: #F7F7F7;>
x-product < display: inline-block; float: left; margin: 0.5em; border-radius: 3px; background: #FFF; box-shadow: 0 1px 3px rgba(0,0,0,0.25); font-family: Helvetica, arial, sans-serif; -webkit-font-smoothing: antialiased;>
x-product::slotted(.product-img) < cursor: pointer; background: #FFF; margin: 0.5em;>
x-product::slotted(.product-name)

If nothing appeared below, then your browser does not support Custom Elements yet.

Is there a way to create your own html tag in HTML5?

You can use custom tags in browsers, although they won’t be HTML5 (see Are custom elements valid HTML5? and the HTML5 spec).

Let’s assume you want to use a custom tag element called . Here’s what you should do.

Normalize its attributes in your CSS Stylesheet (think css reset) —
Example:

To get it to work in old versions of Internet Explorer, you need to append this script to the head (Important if you need it to work in older versions of IE!):