developit/*Preact Without Build Tools.md

## *Preact Without Build Tools.md

      
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              *Preact Without Build Tools.md
            
          
    Preact, Without Build Tools

This is a demonstration of using Preact without any build tooling.
The library is linked from the esm.sh CDN, however a standalone JS file exporting HTM + Preact + Hooks can also be downloaded here.

  
## index.html
<!DOCTYPE html>
<html>
  <head>
    <title>Preact Without Tooling</title>
    <style>
      ul { list-style: none; padding: 0; }
      label { padding: 5px; display: flex; gap: 5px; }
    </style>
  </head>
  <body>
    <script type="module" src="./main.js"></script>
  </body>
</html>

## main.js
import { render } from 'https://esm.sh/preact@10.7.2';
import { useState, useCallback } from 'https://esm.sh/preact@10.7.2/hooks';
import { html } from 'https://esm.sh/htm@3.0.4/preact';

const INITIAL_TODOS = [
  { text: 'add HTM imports', done: true },
  { text: 'remove bundler', done: true },
  { text: 'write code', done: false }
];

function App() {
  const [todos, setTodos] = useState(INITIAL_TODOS);

  console.log(todos);

  const add = useCallback(e => {
    const text = e.target.todo.value;
    setTodos(todos => todos.concat({ text, done: false }));
  }, []);

  const updateTodo = useCallback(todo => {
    // we update the todo in-place, so just invalidate the list to re-render:
    setTodos(todos => todos.slice());
  }, []);

  return html`
    <div class="app">
      <form action="javascript:" onSubmit=${add}>
        <input name="todo" placeholder="Add Todo [enter]" />
      </form>
      <ul>
        ${todos.map(todo => html`
          <${Todo} todo=${todo} onChange=${updateTodo} />
        `)}
      </ul>
    </div>
  `;
}

function Todo({ todo, onChange }) {
  const toggle = useCallback(e => {
    todo.done = !todo.done;
    onChange();
  }, []);

  return html`
    <li>
      <label>
        <input type="checkbox" checked=${todo.done} onClick=${toggle} />
        ${todo.text}
      </label>
    </li>
  `;
}

render(html`<${App} />`, document.body);
	<!DOCTYPE html>
	<html>
	<head>
	<title>Preact Without Tooling</title>
	<style>
	ul { list-style: none; padding: 0; }
	label { padding: 5px; display: flex; gap: 5px; }
	</style>
	</head>
	<body>
	<script type="module" src="./main.js"></script>
	</body>
	</html>
	import { render } from 'https://esm.sh/preact@10.7.2';
	import { useState, useCallback } from 'https://esm.sh/preact@10.7.2/hooks';
	import { html } from 'https://esm.sh/htm@3.0.4/preact';

	const INITIAL_TODOS = [
	{ text: 'add HTM imports', done: true },
	{ text: 'remove bundler', done: true },
	{ text: 'write code', done: false }
	];

	function App() {
	const [todos, setTodos] = useState(INITIAL_TODOS);

	console.log(todos);

	const add = useCallback(e => {
	const text = e.target.todo.value;
	setTodos(todos => todos.concat({ text, done: false }));
	}, []);

	const updateTodo = useCallback(todo => {
	// we update the todo in-place, so just invalidate the list to re-render:
	setTodos(todos => todos.slice());
	}, []);

	return html`
	<div class="app">
	<form action="javascript:" onSubmit=${add}>
	<input name="todo" placeholder="Add Todo [enter]" />
	</form>
	<ul>
	${todos.map(todo => html`
	<${Todo} todo=${todo} onChange=${updateTodo} />
	`)}
	</ul>
	</div>
	`;
	}

	function Todo({ todo, onChange }) {
	const toggle = useCallback(e => {
	todo.done = !todo.done;
	onChange();
	}, []);

	return html`
	<li>
	<label>
	<input type="checkbox" checked=${todo.done} onClick=${toggle} />
	${todo.text}
	</label>
	</li>
	`;
	}

	render(html`<${App} />`, document.body);