Sapper SSR svelte: trying to add toast ui to the default template in index.svelte

wolfiton profile image wolfiton ・1 min read

Hi everyone,

I am trying to add toast-ui editor to the default sapper webpack template.
Create a github repo with the problem here
This is my index.svelte from src/routes and my moddifications so far:

  import { onMount } from "svelte";
  import marked from "marked";

  let markdown = "# Example Title\n\n- this\n- is\n- a list";

  onMount(async () => {
    let Editor = await import('@toast-ui/editor');
    const editor = new Editor({
      target: document.querySelector("#editor"),
      height: "500px",
      initialEditType: "markdown",
      previewStyle: "vertical"

  p {
    text-align: center;
    margin: 0 auto;

  h1 {
    font-size: 2.8em;
    text-transform: uppercase;
    font-weight: 700;
    margin: 0 0 0.5em 0;

  figure {
    margin: 0 0 1em 0;

  img {
    width: 100%;
    max-width: 400px;
    margin: 0 0 1em 0;

  p {
    margin: 1em auto;

  @media (min-width: 480px) {
    h1 {
      font-size: 4em;

  <title>Sapper project template</title>

<h1>Great success!</h1>

  <img alt="Success Kid" src="successkid.jpg" />
  <figcaption>Have fun with Sapper!</figcaption>
<textarea bind:value={markdown} placeholder="Enter markdown here" />
<div class="preview">
  {@html marked(markdown)}
<div id="editor" />
    Try editing this file (src/routes/index.svelte) to test live reloading.

My question is how to make this work and get rid of this error:

TypeError: Editor is not a constructor

Thanks in advance

Posted on by:

wolfiton profile



I am a certified trainer that likes to share my knowledge with the world. Also, I am an adopter of continuous learning and evolving idea. https://dev.to/wolfiton/who-am-i-3lj7


Editor guide

I would pose questions like this on the svelte discord channel, not on a blogging platform like dev.to! They will be able to help you much more efficiently there. discord.com/invite/yy75DKs



I come from the svelte discord because I didn't receive more help than where I am now.

So I am also trying to see what I can learn here.

Thanks @mattwaler for the suggestion