reactivity.html

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8" />
        <meta http-equiv="X-UA-Compatible" content="IE=edge" />
        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
        <title>🧡</title>
        <script src="tailwind.js"></script>
    </head>
    <body>
        <div class="flex h-screen items-center justify-center">
            <div id="app"></div>
        </div>
        <script src="https://unpkg.com/vue@3/dist/vue.global.js"></script>

        <script type="module">
            // Import reactivity elements from Vue
            const { ref, watch } = Vue;

            // Import vdom elemens from our own VDOM engine
            import { h, mount, patch } from './vue-vdom.js';

            const counter = ref(0);

            // Render function
            const render = () => {
                return h('div', { class: 'text-center' }, [
                    h(
                        'h1',
                        { class: 'text-3xl font-bold' },
                        `Count: ${counter.value}`
                    ),
                    h(
                        'button',
                        {
                            class: 'bg-gray-200 p-2 rounded',
                            onClick: () => counter.value++,
                        },
                        'Click!'
                    ),
                ]);
            };

            // Initial DOM tree
            let vdom = render();

            // Mount the DOM tree
            const app = document.getElementById('app');
            mount(vdom, app);

            // Watch for changes in the counter
            watch(counter, () => {
                // Patch the DOM tree
                const vdomNew = render();
                patch(vdom, vdomNew);
                vdom = vdomNew;
            });
        </script>
    </body>
</html>