Write a plugin

Use a plugin when a feature needs an editor-owned lifecycle. Start with a plain EditorPlugin, then use the extension entry point for commands and view contributions.

1. Define a plugin

import { Editor } from '@singapore-editor/core/editor'import type { EditorPlugin } from '@singapore-editor/core/extensions'const lifecyclePlugin: EditorPlugin = {  name: 'example.lifecycle',  activate() {    console.log('Editor feature active')    return { dispose: () => console.log('Editor feature released') }  },}const editor = new Editor(document.querySelector<HTMLElement>('#editor')!, {  plugins: [lifecyclePlugin],})

2. Own the cleanup

The disposable returned by activation releases the feature's work when that activation ends. A plugin that starts a worker, subscribes to host state or mounts DOM must release those resources through its lifecycle. Disposing the editor releases its owned plugin activations.

3. Add only the contributions you need

The /extensions entry point exposes view contributions, capability tokens and decoration APIs. The experimental createPlugin authoring API uses named inputs and view scopes to describe the data a feature reads. Its public API can still change. Consult the generated reference before adopting it.

Plugins can work on an editor given plain text. Add a document id or external session when a feature needs shared identity, and support plain options when it only needs a URI or language.

Scroll gutters in a reading view

Line numbers and fold markers stay at the left edge by default. For a documentation code block,

set gutterScroll: 'content' on the editor. All gutter lanes then move horizontally with the text,

including any leading inset.

import { Editor } from '@singapore-editor/core/editor'import { createFoldGutterPlugin, createLineGutterPlugin } from '@singapore-editor/gutters'const editor = new Editor(document.querySelector<HTMLElement>('#editor')!, {  gutterScroll: 'content',  plugins: [createLineGutterPlugin(), createFoldGutterPlugin()],})editor.setText('A line of text to read')

Gutters stay aligned with virtualized rows during vertical scrolling. Word wrap keeps its usual

text width and continuation-row labels. Set gutterScroll: 'fixed', or call

editor.setGutterScroll('fixed'), to keep gutters at the viewport edge.

If it doesn't work

A feature still runs after closing the editor

Put each listener and worker under an owned disposable. Check externally supplied services separately from the editor's resources.

The plugin works only for named documents

Check whether the feature actually needs shared identity. A URI or language can be a plain integration option for an unnamed editor.

Continue with the packages reference and workers.