// src/plugin.ts - Register client module with getClientModules()
export default function myPlugin(context, options): Plugin {
  return {
    name: 'my-plugin',
    getClientModules() {
      return [require.resolve('./client')];
    },
  };
}

// src/client/index.ts - Enhance DOM automatically on every page
import ExecutionEnvironment from '@docusaurus/ExecutionEnvironment';

export default (function () {
  if (!ExecutionEnvironment.canUseDOM) return null;

  return {
    onRouteUpdate({ location }) {
      // Runs on every route change - enhance elements automatically
      document.querySelectorAll('.markdown img').forEach(img => {
        img.style.cursor = 'zoom-in';
        img.addEventListener('click', () => console.log('Image clicked'));
      });
    },
  };
})();

Core Principles

Global Execution: Client modules via getClientModules() run on every page automatically—no manual imports needed in content files
SSR Safety: Always check ExecutionEnvironment.canUseDOM before using browser APIs to prevent SSR errors
Lifecycle Hooks: Use onRouteUpdate for DOM manipulation that needs to reinitialize on every SPA navigation
DOM Selectors: Use CSS selectors to find target elements (e.g., .markdown img, pre code) and enhance them
Server vs Client: Keep Node.js code in src/plugin.ts, browser code in src/client/ - never mix them

Common Patterns

Pattern 1: DOM Enhancement (Image Zoom, Code Copy)

Use onRouteUpdate with DOM selectors to enhance elements automatically without imports.

Pattern 2: External Library Integration

Initialize third-party libraries (medium-zoom, highlight.js) and reinitialize on route changes.

Pattern 3: Global Event Listeners

Attach keyboard shortcuts or scroll handlers once, persist across routes using initialization flags.

Pattern 4: Plugin Options

Pass configuration from plugin to client via setGlobalData or inline during build.

Reference Files

For detailed documentation:

references/client-modules-guide.md - Comprehensive client modules guide
README.md - Plugin documentation
CONTRIBUTING.md - Development guide

Quick Reference

Plugin Hooks (src/plugin.ts):

loadContent() - Load/process data at build time
contentLoaded() - Inject global data with setGlobalData() or add routes
getClientModules() - Return array of client module paths (runs in browser)

Client Lifecycle (src/client/index.ts):

onRouteUpdate() - During navigation (use for DOM manipulation)
onRouteDidUpdate() - After navigation completes (use for analytics)

Critical Guardrails:

❌ Never import Node modules (fs, path) in src/client/*
✅ Always wrap client code with ExecutionEnvironment.canUseDOM check
✅ Use setTimeout(() => {}, 0) if DOM elements not immediately available
✅ Clean up previous instances before reinitializing libraries