How to export functions and variables from a Svelte component

You know that you can import a Svelte component into another using the syntax

<script>
import Button from './Button.svelte';
</script>

What if you want to export something more than the default export?

Well, you must export it from a special script tag into the component, with the context="module" attribute.

Here’s an example. Say you have a Button component in Button.svelte:

<button>A button</button>

and you want to provide other components the ability to change the color of the button. You could use props, that’s one example. Or you can provide a function, called changeColor.

You write and export it in this special script tag:

<script context="module">
export function changeColor() {
  //...add logic..
}
</script>

<button>A button</button>

Warning: I did not implement the actual functionality, but you get the idea.

Note that you can have another “normal” script tag, in the component.

Now other components can import Button, which is the default export, and the changeColor function too:

<script>
import Button, { changeColor } from './Button.svelte'
</script>