---
id: counter
title: Counter
sidebar_label: Counter (eventListener)
---

## Handling State with eventListener

A simple counter application. This give you basic understanding how to work with DOM eventListener. To attach event we add a ```Node``` ```attribute``` with ```k-<event>``` where ```<event>``` could be one of any types of [Events](https://developer.mozilla.org/en-US/docs/Web/Events) and the value is a string representing one our method in the component class.

```js
import Keet, { html } from 'keet'

class App extends Keet {
  el = 'app'
  count = 0
  add() {
    this.count++
  }
  render() {
    return html`
```
```html
      <button id="counter" k-click="add()">
        {{count}}
      </button>
```
```js
    `
  }
}

const app = new App()
```

## Codepen Sample

<p data-height="265" data-theme-id="dark" data-slug-hash="zpbGBd" data-default-tab="js,result" data-user="syarul" data-pen-title="Keetjs - Counter" class="codepen">See the Pen <a href="https://codepen.io/syarul/pen/zpbGBd/">Keetjs - Counter</a> by Shahrul Nizam b. Selamat (<a href="https://codepen.io/syarul">@syarul</a>) on <a href="https://codepen.io">CodePen</a>.</p>
<script async src="https://static.codepen.io/assets/embed/ei.js"></script>