> ## Documentation Index
> Fetch the complete documentation index at: https://superdoc-caio-pizzol-sd-docs-snippet-typecheck-2.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Events

SuperDoc uses an event system for lifecycle hooks and change notifications.

<Note>
  **Driving live React UI state? Prefer `superdoc/ui` subscriptions.** `useSuperDocSelection`, `useSuperDocComments`, `useSuperDocTrackChanges`, `useSuperDocDocument`, and `useSuperDocCommand` give you typed, memoized, per-slice state with one re-render per change instead of a manual `superdoc.on('editor-update', ...)` loop. See [Custom UI](/editor/custom-ui/overview).

  The events on this page are for lifecycle (`ready`, `editor-create`), integration (`error`, `comment-changed`), analytics, and compatibility with code that doesn't use the React surface.
</Note>

## Subscribing to events

<CodeGroup>
  ```javascript Usage theme={null}
  superdoc.on('ready', handler);     // Subscribe
  superdoc.once('ready', handler);   // One-time listener
  superdoc.off('ready', handler);    // Unsubscribe
  ```

  ```javascript Full Example theme={null}
  import { SuperDoc } from 'superdoc';
  import 'superdoc/style.css';

  const superdoc = new SuperDoc({
    selector: '#editor',
    document: yourFile,
  });

  /** @param {import('superdoc').SuperDocReadyPayload} payload */
  const handler = ({ superdoc }) => {
    console.log('Handler called');
  };

  superdoc.on('ready', handler);     // Subscribe
  superdoc.once('ready', handler);   // One-time listener
  superdoc.off('ready', handler);    // Unsubscribe
  ```
</CodeGroup>

## Lifecycle events

### `ready`

Fired when SuperDoc is fully initialized.

<CodeGroup>
  ```javascript Usage theme={null}
  superdoc.on('ready', ({ superdoc }) => {
    // Safe to use all features
  });
  ```

  ```javascript Full Example theme={null}
  import { SuperDoc } from 'superdoc';
  import 'superdoc/style.css';

  const superdoc = new SuperDoc({
    selector: '#editor',
    document: yourFile,
  });

  superdoc.on('ready', ({ superdoc }) => {
    // Safe to use all features
  });
  ```
</CodeGroup>

### `editorBeforeCreate`

Fired before an editor is created. Use this to configure extensions or set up services.

<CodeGroup>
  ```javascript Usage theme={null}
  superdoc.on('editorBeforeCreate', ({ editor }) => {
    // Configure before editor mounts
  });
  ```

  ```javascript Full Example theme={null}
  import { SuperDoc } from 'superdoc';
  import 'superdoc/style.css';

  const superdoc = new SuperDoc({
    selector: '#editor',
    document: yourFile,
  });

  superdoc.on('editorBeforeCreate', ({ editor }) => {
    // Configure before editor mounts
  });
  ```
</CodeGroup>

### `editorCreate`

When an editor is created.

<CodeGroup>
  ```javascript Usage theme={null}
  superdoc.on('editorCreate', ({ editor }) => {
    editor.focus();
  });
  ```

  ```javascript Full Example theme={null}
  import { SuperDoc } from 'superdoc';
  import 'superdoc/style.css';

  const superdoc = new SuperDoc({
    selector: '#editor',
    document: yourFile,
  });

  superdoc.on('editorCreate', ({ editor }) => {
    editor.focus();
  });
  ```
</CodeGroup>

### `editorDestroy`

When an editor is destroyed.

<CodeGroup>
  ```javascript Usage theme={null}
  superdoc.on('editorDestroy', () => {
    cleanup();
  });
  ```

  ```javascript Full Example theme={null}
  import { SuperDoc } from 'superdoc';
  import 'superdoc/style.css';

  const superdoc = new SuperDoc({
    selector: '#editor',
    document: yourFile,
  });

  superdoc.on('editorDestroy', () => {
    cleanup();
  });
  ```
</CodeGroup>

## Content events

### `editor-update`

When editor content changes. Use this to refresh live UI state like word counts or auto-save.

<CodeGroup>
  ```javascript Usage theme={null}
  superdoc.on('editor-update', ({ editor }) => {
    if (!editor) return;
    autoSave(editor.getJSON());
  });
  ```

  ```javascript Full Example theme={null}
  import { SuperDoc } from 'superdoc';
  import 'superdoc/style.css';

  const superdoc = new SuperDoc({
    selector: '#editor',
    document: yourFile,
  });

  superdoc.on('editor-update', ({ editor }) => {
    if (!editor) return;
    autoSave(editor.getJSON());
  });
  ```
</CodeGroup>

**Live counter example:** Read `editor.doc.info()` inside the handler to build a live document-stats panel without polling.

```javascript theme={null}
superdoc.on('editor-update', ({ editor }) => {
  const { counts } = editor.doc.info();
  document.getElementById('stats').textContent =
    `${counts.words} words, ${counts.characters} characters, ` +
    `${counts.trackedChanges} tracked changes, ${counts.lists} lists`;
});
```

### `content-error`

When content processing fails.

<CodeGroup>
  ```javascript Usage theme={null}
  superdoc.on('content-error', ({ error, editor }) => {
    console.error('Content error:', error);
  });
  ```

  ```javascript Full Example theme={null}
  import { SuperDoc } from 'superdoc';
  import 'superdoc/style.css';

  const superdoc = new SuperDoc({
    selector: '#editor',
    document: yourFile,
  });

  superdoc.on('content-error', ({ error, editor }) => {
    console.error('Content error:', error);
  });
  ```
</CodeGroup>

### `fonts-resolved`

When document fonts are resolved.

<CodeGroup>
  ```javascript Usage theme={null}
  superdoc.on('fonts-resolved', ({ documentFonts, unsupportedFonts }) => {
    if (unsupportedFonts.length > 0) {
      console.warn('Unsupported fonts:', unsupportedFonts.join(', '));
    }
  });
  ```

  ```javascript Full Example theme={null}
  import { SuperDoc } from 'superdoc';
  import 'superdoc/style.css';

  const superdoc = new SuperDoc({
    selector: '#editor',
    document: yourFile,
  });

  superdoc.on('fonts-resolved', ({ documentFonts, unsupportedFonts }) => {
    if (unsupportedFonts.length > 0) {
      console.warn('Unsupported fonts:', unsupportedFonts.join(', '));
    }
  });
  ```
</CodeGroup>

## Comments events

### `comments-update`

When comments are modified.

<CodeGroup>
  ```javascript Usage theme={null}
  superdoc.on('comments-update', ({ type, comment, changes }) => {
    // type: 'add', 'update', 'deleted', 'resolved'
    // comment: the comment object (when applicable)
    // changes: per-field change set (when the update is a mutation)
  });
  ```

  ```javascript Full Example theme={null}
  import { SuperDoc } from 'superdoc';
  import 'superdoc/style.css';

  const superdoc = new SuperDoc({
    selector: '#editor',
    document: yourFile,
  });

  superdoc.on('comments-update', ({ type, comment, changes }) => {
    // type: 'add', 'update', 'deleted', 'resolved'
    // comment: the comment object (when applicable)
    // changes: per-field change set (when the update is a mutation)
  });
  ```
</CodeGroup>

## Collaboration events

### `collaboration-ready`

When collaboration is initialized.

<CodeGroup>
  ```javascript Usage theme={null}
  superdoc.on('collaboration-ready', ({ editor }) => {
    showOnlineUsers();
  });
  ```

  ```javascript Full Example theme={null}
  import { SuperDoc } from 'superdoc';
  import 'superdoc/style.css';

  const superdoc = new SuperDoc({
    selector: '#editor',
    document: yourFile,
  });

  superdoc.on('collaboration-ready', ({ editor }) => {
    showOnlineUsers();
  });
  ```
</CodeGroup>

### `awareness-update`

When user presence changes.

<CodeGroup>
  ```javascript Usage theme={null}
  superdoc.on('awareness-update', ({ states, added, removed }) => {
    updateUserCursors(states);
  });
  ```

  ```javascript Full Example theme={null}
  import { SuperDoc } from 'superdoc';
  import 'superdoc/style.css';

  const superdoc = new SuperDoc({
    selector: '#editor',
    document: yourFile,
  });

  superdoc.on('awareness-update', ({ states, added, removed }) => {
    updateUserCursors(states);
  });
  ```
</CodeGroup>

### `locked`

When document lock state changes.

<CodeGroup>
  ```javascript Usage theme={null}
  superdoc.on('locked', ({ isLocked, lockedBy }) => {
    if (isLocked && lockedBy) {
      showLockBanner(`Locked by ${lockedBy.name}`);
    }
  });
  ```

  ```javascript Full Example theme={null}
  import { SuperDoc } from 'superdoc';
  import 'superdoc/style.css';

  const superdoc = new SuperDoc({
    selector: '#editor',
    document: yourFile,
  });

  superdoc.on('locked', ({ isLocked, lockedBy }) => {
    if (isLocked && lockedBy) {
      showLockBanner(`Locked by ${lockedBy.name}`);
    }
  });
  ```
</CodeGroup>

## Pagination events

### `pagination-update`

Fired after each layout pass with the current page count. Use this to know when page data is available: `activeEditor.currentTotalPages` is only populated after the first layout completes, which happens *after* the `ready` event.

<CodeGroup>
  ```javascript Usage theme={null}
  superdoc.on('pagination-update', ({ totalPages, superdoc }) => {
    console.log(`Document has ${totalPages} pages`);
  });
  ```

  ```javascript Full Example theme={null}
  import { SuperDoc } from 'superdoc';
  import 'superdoc/style.css';

  const superdoc = new SuperDoc({
    selector: '#editor',
    document: yourFile,
  });

  superdoc.on('pagination-update', ({ totalPages, superdoc }) => {
    console.log(`Document has ${totalPages} pages`);
  });
  ```
</CodeGroup>

## UI events

### `zoomChange`

When the zoom level changes via `setZoom()`.

<CodeGroup>
  ```javascript Usage theme={null}
  superdoc.on('zoomChange', ({ zoom }) => {
    console.log(`Zoom: ${zoom}%`);
  });
  ```

  ```javascript Full Example theme={null}
  import { SuperDoc } from 'superdoc';
  import 'superdoc/style.css';

  const superdoc = new SuperDoc({
    selector: '#editor',
    document: yourFile,
  });

  superdoc.on('zoomChange', ({ zoom }) => {
    console.log(`Zoom: ${zoom}%`);
  });
  ```
</CodeGroup>

### `sidebar-toggle`

When the comments sidebar is toggled.

<CodeGroup>
  ```javascript Usage theme={null}
  superdoc.on('sidebar-toggle', (isOpened) => {
    adjustLayout(isOpened);
  });
  ```

  ```javascript Full Example theme={null}
  import { SuperDoc } from 'superdoc';
  import 'superdoc/style.css';

  const superdoc = new SuperDoc({
    selector: '#editor',
    document: yourFile,
  });

  superdoc.on('sidebar-toggle', (isOpened) => {
    adjustLayout(isOpened);
  });
  ```
</CodeGroup>

## Error events

### `exception`

When an error occurs during document processing or runtime.

<CodeGroup>
  ```javascript Usage theme={null}
  superdoc.on('exception', (payload) => {
    // `payload` is a discriminated union; narrow before reading variant-specific fields.
    // `code` is only on the editor-lifecycle variant; `stage` is only on document-init.
    console.error('SuperDoc error:', payload.error);
  });
  ```

  ```javascript Full Example theme={null}
  import { SuperDoc } from 'superdoc';
  import 'superdoc/style.css';

  const superdoc = new SuperDoc({
    selector: '#editor',
    document: yourFile,
  });

  superdoc.on('exception', (payload) => {
    // `payload` is a discriminated union; narrow before reading variant-specific fields.
    // `code` is only on the editor-lifecycle variant; `stage` is only on document-init.
    console.error('SuperDoc error:', payload.error);
  });
  ```
</CodeGroup>

## Configuration-based events

Events can also be set during initialization:

```javascript theme={null}
new SuperDoc({
  selector: '#editor',
  document: 'document.docx',
  onReady: ({ superdoc }) => { },
  onEditorBeforeCreate: ({ editor }) => { },
  onEditorCreate: ({ editor }) => { },
  onEditorUpdate: ({ editor }) => { },
  onFontsResolved: ({ documentFonts, unsupportedFonts }) => { },
  onPaginationUpdate: ({ totalPages, superdoc }) => { },
  onSidebarToggle: (isOpened) => { },
  onException: ({ error }) => { },
});
```

## Event order

1. `editorBeforeCreate`: Before editor mounts
2. `editorCreate`: Editor ready
3. `ready`: All editors ready
4. `collaboration-ready`: If collaboration enabled
5. `pagination-update`: After each layout pass (page count available)
6. Runtime events (`editor-update`, `comments-update`, `sidebar-toggle`, etc.)
7. `editorDestroy`: Cleanup