Collection of Polyfills for kluntje usage

npm install @kluntje/polyfills@0.1.0


Welcome to kluntje👋

License: Apache 2.0 Commitizen friendly

Kluntje is a javascript library that brings web components to the next level. Take a look and make web components development a breeze.

🚀 Why Kluntje?

Kluntje is the right tool if you want to use web components with the feeling of a modern javascript framework. It fits well to CMS projects and works with every JS framework.

  • It can hydrate existing (ie. server-side rendered) markup and does not require to render client-side (although it can)
  • It does not force you to use shadow-dom (but you can)
  • It has states and customizable state-reactions
  • It adds helpful lifecycle hooks
  • It is < 3Kb

Getting Started

These instructions will get you a copy of the project up and running on your local machine for development purposes.


Getting the project up and running is pretty straight forward:

npm install @kluntje/core

And you are done.


Import the Kluntje core component in your js file and you can start using it:

import { Component } from "@kluntje/Core";

class MyAmazingComponent extends Component {

customElements.define("my-amazing-component", MyAmazingComponent);

And use it in your HTML file:


How our components look like

Kluntje-Components are defined as classes which extend from our core-component. Functionality can be added in multiple ways:

  • of course you can always add properties and methods to your class
  • you can also provide a constructor object to add all kinds features
  • additionally you can use a set of decorators to easily connect to DOM-Elements, attributes etc.

For further documentatation see core, services and js-utils.


import { Component } from "@kluntje/core";

class IncrementInput extends Component {
  constructor() {
      ui: {
        input: "input :-one",
        button: ".handle-increment :-one",
      events: [
          event: "click",
          target: "button",
          handler: "handleClick",
      initialStates: {
        value: 1,
      reactions: {
        value: ["handleIncrement"],
  afterComponentRender() {
    this.ui.input.value = this.state.value;    
  handleClick() {
    this.setState({ value: this.state.value + 1});
  handleIncrement({value}) {
    this.ui.input.value = value;

customElements.define("increment-input", IncrementInput);

You can also use decorators to query elements, define props and bind events. Using decorators, our increment-input component could look like this:

import { Component, uiElement, uiEvent, prop } from "@kluntje/core";

class IncrementInput extends Component {

  input: HTMLInputElement;

  button: HTMLButtonElement;

  @prop({ defaultValue: 0, reactions: ["handleIncrement"], reactOnInit: true })
  incrementValue: number;

  @uiEvent("button", "click")
  handleClick() {
    this.incrementValue += 1;

  handleIncrement() {
    this.input.value = this.incrementValue.toString();

customElements.define("increment-input", IncrementInput);

And our HTML will look like:

    <input type="number" />
    <button class="handle-increment">Increment</button>


Please read CONTRIBUTING.md for details on our code of conduct, and the process for submitting pull requests to us.

👤 Frederik Riewerts frederik.riewerts@gmail.com

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📝 License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details