> **>>> TLDR;** See the [Quick Start Example](#quick-start-example) you can just copy, refactor, and modify
Web Component Base
---
[](https://www.npmjs.com/package/web-component-base)
[](https://www.npmjs.com/package/web-component-base)
[](https://www.npmjs.com/package/web-component-base)
This provides a very minimal base class for creating reactive custom elements easily.
When you extend the `WebComponent` class for your component, you only have to define the `template` and `properties`. Any change in any property value will automatically cause just the component UI to render.
The result is a reactive UI on property changes.
## Table of Contents
1. [Import via unpkg](#import-via-unpkg)
1. ~~[Installation via npm](#installation-via-npm)~~ - in-progress
1. [Usage](#usage)
1. [Quick Start Example](#quick-start-example)
1. [Life-Cycle Hooks](#life-cycle-hooks)
1. [`onInit`](#oninit) - the component is connected to the DOM, before view is initialized
1. [`afterViewInit`](#afterviewinit) - after the view is first initialized
1. [`onChanges`](#onchanges) - every time an attribute value changes
## Import via unpkg
Import using [unpkg](https://unpkg.com/web-component-base) in your component. We will use this in the rest of our [usage examples](#usage).
```js
import WebComponent from "https://unpkg.com/web-component-base";
// or a specific version
import WebComponent from "https://unpkg.com/web-component-base@1.6.0/index.mjs";
```
## ~~Installation via npm~~ - in-progress
Still fixing the module for this to be used as a node module
## Usage
In your component class:
```js
// HelloWorld.mjs
import WebComponent from "https://unpkg.com/web-component-base";
class HelloWorld extends WebComponent {
name = "World";
emotion = "excited";
static properties = ["name", "emotion"];
get template() {
return `
Hello ${this.name}${this.emotion === "sad" ? ". ðŸ˜" : "! 🙌"}
`;
}
}
customElements.define('hello-world', HelloWorld);
```
In your HTML page:
```html
```
The result is a reactive UI that updates on attribute changes:
## Quick Start Example
Here is an example of using a custom element in a single .html file:
```html
WC Base Test
```
## Life-Cycle Hooks
Define behavior when certain events in the component's life cycle is triggered by providing hook methods
### onInit()
- triggered when the component is connected to the DOM
- best for setting up the component
```js
import WebComponent from "https://unpkg.com/web-component-base";
class ClickableText extends WebComponent {
// gets called when the component is used in an HTML document
onInit() {
this.onclick = () => console.log(">>> click!");
}
get template() {
return `Click me!`;
}
}
```
### afterViewInit()
- triggered after the view is first initialized
```js
class ClickableText extends WebComponent {
// gets called when the component's innerHTML is first filled
afterViewInit() {
const footer = this.querySelector('footer');
// do stuff to footer after view is initialized
}
get template() {
return ``;
}
}
```
### onChanges()
- triggered when an attribute value changed
```js
import WebComponent from "https://unpkg.com/web-component-base";
class ClickableText extends WebComponent {
// gets called when an attribute value changes
onChanges(changes) {
const {property, previousValue, currentValue} = changes;
console.log('>>> ', {property, previousValue, currentValue})
}
get template() {
return `Click me!`;
}
}
```