anywidget svelte demo

README.md

anywidget-svelte

This is a toy example demonstrating how to start prototyping with Svelte in anywidget.

Since Svelte requires a compiler, we need to configure a bundler to prototype our widget. This example extends from the Vite recipe in the documentation, and importantly adds the svelte compiler in the vite.config.js.

Make sure you have a Python environment with anywidget installed and the Node.js dependencies:

pip install jupyterlab anywidget
pnpm install

To get started you will need to run both a notebook server:

jupyterlab SvelteDemo.ipynb # open notebook

and run the vite dev server:

pnpm vite # run vite development server

You can now start developing the widget. Any changes to the JavaScript/Svelte source are automatically reflected in the notebook frontend.

Note: this example is incomplete and only demonstrates live prototyping with the development server. Follow the rest of the Vite recipe to learn the recommended bundling strategy for production.

Counter.svelte

<script>
	import { onDestroy, onMount } from "svelte";

	export let model;
	export let name = "value";

	let count = model.get(name);
	let event = `change:${name}`
	let callback = () => count = model.get(name);

	onMount(() => {
		model.on(event, callback);
	});

	onDestroy(() => {
		model.off(event, callback);
	})

</script>

<button on:click={() => {
	model.set(name, model.get(name) + 1);
	model.save_changes();
}}>
	Count is {count}
</button>

<style>
	button {
		padding: 10px;
		font-size: 2em;
	}
</style>

index.js

import Counter from "./Counter.svelte";

export function render({ model, el }) {
	let counter = new Counter({ target: el, props: { model } });
	return () => counter.$destroy();
}

package.json

{
  "name": "anywidget-svelte",
  "type": "module",
  "devDependencies": {
    "@anywidget/vite": "^0.1.1",
    "@sveltejs/vite-plugin-svelte": "^2.4.2",
    "vite": "^4.4.1"
  },
  "dependencies": {
    "svelte": "^4.0.5"
  }
}

SvelteDemo.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "48e6db1b",
   "metadata": {},
   "outputs": [],
   "source": [
    "import anywidget\n",
    "import traitlets\n",
    "\n",
    "\n",
    "class SvelteCounter(anywidget.AnyWidget):\n",
    "    _esm = \"http://localhost:5173/index.js?anywidget\"\n",
    "    value = traitlets.Int().tag(sync=True)\n",
    "    \n",
    "counter = SvelteCounter()\n",
    "counter"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "1dbeb4fd",
   "metadata": {},
   "outputs": [],
   "source": [
    "counter"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "7149bd0c",
   "metadata": {},
   "outputs": [],
   "source": [
    "counter.value = 12"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "23b0f842",
   "metadata": {},
   "outputs": [],
   "source": []
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Python 3 (ipykernel)",
   "language": "python",
   "name": "python3"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.11.0"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 5
}

vite.config.js

import { defineConfig } from "vite";
import anywidget from "@anywidget/vite";
import { svelte } from "@sveltejs/vite-plugin-svelte";

export default defineConfig({
	plugins: [
		svelte({ hot: false }),
		anywidget(),
	],
});