#RunJS Overview

RunJS is the JavaScript execution environment used in NocoBase for scenarios such as JS Blocks, JS Fields, and JS Actions. Code runs in a restricted sandbox, providing safe access to the ctx (Context API) and includes the following capabilities:

• Top-level await
• Importing external modules
• Rendering within containers
• Global variables

#Top-level await

RunJS supports top-level await, eliminating the need to wrap code in an IIFE.

Not Recommended

async function test() {}
(async () => {
  await test();
})();

Recommended

async function test() {}
await test();

#Importing External Modules

• Use ctx.importAsync() for ESM modules (Recommended)
• Use ctx.requireAsync() for UMD/AMD modules

#Rendering within Containers

Use ctx.render() to render content into the current container (ctx.element). It supports the following three formats:

#Rendering JSX

ctx.render(<button>Button</button>);

#Rendering DOM Nodes

const div = document.createElement('div');
div.innerHTML = 'Hello World';

ctx.render(div);

#Rendering HTML Strings

ctx.render('<h1>Hello World</h1>');

#Global Variables

• window
• document
• navigator
• ctx