Bidi Isolation Plugin

The BidiIsolationPlugin registers a bdi mark for inline bidi isolation — wrapping selected text in a <bdi> element with an explicit dir attribute. Use it when a single block contains text in mixed directions (e.g., an English phrase inside an Arabic paragraph).

It is independent of the Text Direction plugin, but consumes the optional TextDirectionService for a smarter toggleBidiIsolation cycle: when the surrounding block is RTL, the toggled isolation defaults to LTR, and vice versa. Without TextDirectionPlugin registered, toggleBidiIsolation always applies rtl as the starting direction.

Usage

import { BidiIsolationPlugin } from '@notectl/core/plugins/bidi-isolation';

new BidiIsolationPlugin();

Configuration

interface BidiIsolationConfig {
  /** Custom locale for toolbar labels and announcements. */
  readonly locale?: BidiIsolationLocale;
}

Mark Spec

Type	HTML Tag	Attributes	Description
bdi	<bdi>	dir="ltr" | "rtl" | "auto"	Inline bidi isolation element

Commands

Command	Description	Returns
toggleBidiLTR	Apply inline LTR isolation to selection	boolean
toggleBidiRTL	Apply inline RTL isolation to selection	boolean
toggleBidiAuto	Apply inline auto isolation to selection	boolean
removeBidi	Remove inline direction isolation	boolean
toggleBidiIsolation	Toggle bidi: applies opposite of block direction (or 'rtl' as fallback), or removes if already active	boolean

editor.executeCommand('toggleBidiLTR');
editor.executeCommand('removeBidi');

Keyboard Shortcuts

Shortcut	Action
Ctrl+Shift+B / Cmd+Shift+B	Toggle inline bidi isolation

Toolbar

Renders an Inline Direction toolbar dropdown (format group) with LTR, RTL, Auto, and Remove options. Only enabled when text is selected.

Optional Service Consumer

When TextDirectionPlugin is also registered, the toggleBidiIsolation command picks the opposite of the surrounding block’s direction so the isolated word visually stands out. Without it, the toggle defaults to 'rtl'.

Accessibility

• Uses the semantic HTML <bdi> element for proper bidi isolation in assistive technology
• Screen reader announcements for all bidi changes via context.announce()
• Keyboard accessible via Mod-Shift-B
• Toolbar items keyboard navigable

Internationalization

Ships with translations for 9 languages (ar, de, en, es, fr, hi, pt, ru, zh). Custom locales can be provided via the locale config option.