Update: use the official implementation @anywidget/svelte instead (it has a better API too!)

If you want to create svelte components on jupyter notebooks use anywidget + svelte.

To make things easier I've created an interface to create svelte writable stores that sync with anywidget. You don't even have to think about anywidget!

Copy and paste the anywidgetStore.js file into your svelte project or just import it like I did (in Counter.svelte).

Then, in your svelte file you must register the anywidget model (returned from the render function (see main.js and Counter.svelte) in the svelte project).

<script>
	import { anywritable, register } from "./anywidgetStore"
	export let model; // anywidget model
	register(model); // register anywidget model once ever, then can use anywritable() across any component

	// these are normal svelte stores synced with your notebook
	// you change the value in the python notebook, this svelte store will automatically update
        // you change the svelte store value, the python notebook value will auotmatically update
	const count = anywritable("count"); // "count" is the name of the reactive value on the anywidget python class
</script>


<button
	on:click={() => {
		$count++;
	}}
>
	{$count}
</button>

Notice the svelte store syntax $. It's that easy!

And if you want to access the store in other components, just call const count = anywritable("count"); again in that file. It will not create another store, but give you the one you initially created.

Note that you only need to call register(model) once. Then you can call anywritable in any component.

If you want to dispose the listeners, call dispose(name) where name is the name of the traitlet/value.

Or just call disposeAll() if you're lazy like me.

First install dependencies for the svelte components.

cd svelte
yarn

then run the dev server

yarn dev

Then out the example notebook called example.ipynb

Run the notebook!

Check out the svelte files to see how I import things!

I borrowed half the code from Trevor Manz to get svelte up and running with anywidget.

(WIP, still kind of buggy)

Instead of lugging around the anywritable function everywhere, this new syntax simply syncs an existing svelte store with the notebook value from anywidget.

Create the store in a file importable by any component. I'll put it in store.js for future reference.

import { writable } from "svelte/store";

export const count = writable(0);

Then when I have access to the model, I can sync the count svelte store with the notebook by calling syncAnywidget on the count. Like this

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

	import { count } from "./store";
	import { syncAnywidget } from "../../../anywidgetStore";

	export let model;

	// call the sync once, then the stores react to changes and the notebook reacts to store changes
	const disposeCount = syncAnywidget(count, model, "count");

	// disposes all listeners created in the sync
	onDestroy(() => {
		disposeCount();
	});
</script>

(Experimental sync syntax)

<button
	on:click={() => {
		$count++;
	}}
>
	Increment: {$count}
</button>

Now, I can simply import the store in other files, and they will be usable like normal svelte stores! No need to sync again. Just once.

Check out the CounterExperiment.svelte to see a usecase.