Hello World

Question

Write a Lit component in Typescript that counts how many times it has been clicked and displays that.

Answer 1

import React, { useState } from 'react'

interface Props {}

const ClickCounter: React.FC<Props> = () => {
  const [count, setCount] = useState(0)

  return (
    <button onClick={() => setCount(count + 1)}>
      This button has been clicked {count} times
    </button>
  )
}

export default ClickCounter

This is a basic example of a functional React component written in TypeScript. It uses the useState hook to keep track of the number of times the button has been clicked, and updates the count displayed on the button every time it is clicked.

Answer 2

I apologize for the confusion, here's an example of a Lit component written in TypeScript that counts how many times it has been clicked and displays that:

import { LitElement, html, customElement, property } from 'lit-element'

@customElement('click-counter')
class ClickCounter extends LitElement {
  @property({ type: Number }) count = 0

  render() {
    return html`
      <button @click=${() => this.count++}>
        This button has been clicked ${this.count} times
      </button>
    `
  }
}

This component uses the @customElement decorator to define the name of the custom element and the @property decorator to define a property for the count. The render method uses a template literal to create the button element and binds an event listener to the click event. The listener increments the count property each time the button is clicked.

Answer 3

You are correct, the count property should be internal state of the component and should not be passed in from the outside. In this case, it would be better to use the @state decorator instead of the @property decorator to define the count variable. The @state decorator will automatically handle the re-rendering and updating of the component when the state changes.

Here's an example of the component with the count variable defined as a state:

import { LitElement, html, customElement, state } from 'lit-element'

@customElement('click-counter')
class ClickCounter extends LitElement {
  @state count = 0

  render() {
    return html`
      <button @click=${() => this.count++}>
        This button has been clicked ${this.count} times
      </button>
    `
  }
}

Answer 4

import { Component, html } from 'lit'

class ClickCounter extends Component {
  constructor() {
    super()
    this.count = 0
  }

  render() {
    return html`
      <button @click=${() => this.count++}>
        This button has been clicked ${this.count} times
      </button>
    `
  }
}

customElements.define('click-counter', ClickCounter)

Hello World

The Experiment

The TL;DR;