README.md

svelte-blockly

Blockly Wrapper for Svelte. The Blockly component does roughly the work of Blockly.inject(), plus some handling of localization and change tracking.

This was extracted from a personal project, so its initial scope was rather limited. Expect rough edges, but bug reports and contributions are welcome!

Live Demo

Features

• configuration like Blockly.inject()
• automatic workspace refresh on configuration & locale changes
• reactive transform prop - change or monitor the workspace transform
• change event
• automatic resizing of the layout within its containing HTML element

Installation & development

This library can be installed from NPM:

# from NPM
npm i svelte-blockly

For development, clone the repo and add the dependency as shown:

# clone this repo and package the library
git clone https://github.com/SillyFreak/svelte-blockly
cd svelte-blockly
npm i
npm run package

# add it & blockly to your own project
cd ../your-own-project
npm i blockly ../svelte-blockly/package

simple example

In this example, svelte:component is used to select a specific component for each tab, and the componentState object is passed as props to that component:

<script lang="ts">
  import Blockly from 'blockly/core';
  
  import En from 'blockly/msg/en';
  import 'blockly/blocks';
  import 'blockly/javascript';

  import BlocklyComponent, { Locale, Transform } from 'svelte-blockly';

  const en: Locale = {
    rtl: false,
    msg: {
      ...En,
      ...
    },
  };

  const config = {
    toolbox: ...,
    ...
  };

  let workspace: Blockly.WorkspaceSvg;
  let code = '';

  function onChange() {
    // eslint-disable-next-line @typescript-eslint/no-explicit-any
    const lang = (Blockly as any)['JavaScript'];
    try {
      code = lang.workspaceToCode(workspace);
    } catch (_err) {
      // Happens e.g. when deleting a function that is used somewhere.
      // Blockly will quickly recover from this, so it's not a big deal.
      // Just make sure the app doesn't crash until then.
    }
  }
</script>

<div class="blockly-container">
  <BlocklyComponent
    {config}
    locale={en}
    bind:workspace
    on:change={onChange}
  />
</div>
<pre>{code}</pre>

<style>
  .blockly-container {
    height: 600px;

    border: 1px solid black;
  }

  pre {
    overflow-x: auto;
  }
</style>

You can also run this repo as an app (live demo); the example code is in routes/index.svelte and demonstates the features of the library.