Files
leporello-js/docs/examples/preact/index.js
2025-05-30 19:59:02 +00:00

45 lines
846 B
JavaScript

const fib = n => {
if (n == 0) {
return 0
}
if (n == 1) {
return 1
}
return fib(n - 1) + fib(n - 2)
}
/* external */
import { h, render } from "preact"
/* external */
import { Stateful } from "./stateful.js"
const Fibonacci = Stateful({
getInitialState: () => ({ index: 0 }),
handlers: {
prev: ({ index }, event) => ({ index: index - 1 }),
next: ({ index }, event) => ({ index: index + 1 }),
},
render: (props, state, handlers) =>
h(
"div",
null,
h(
"h1",
null,
"nth Fibonacci number is ",
fib(state.index),
" for n = ",
state.index,
),
h("button", { onClick: handlers.prev }, "Previous"),
" ",
h("button", { onClick: handlers.next }, "Next"),
" ",
),
})
render(h(Fibonacci), globalThis.document.body)