Changelog

v4.4.0 - 10/25/2025

Features

• Feature(light-disclosure): Added noAnimation / no-animation property & attribute respectively to turn off disclosure animations.
• Feature(light-pen): Added re-exported parts for the <light-disclosure> which contains html / css / js respectively.

Bug fixes

• Bug Fix(light-disclosure): Now properly renders on connect in the “open” state.
• Bug Fix(light-pen): Now properly renders disclosures in the open

Deprecations

• Deprecation(light-pen) - light-pen::part(disclosure-${language}) have been deprecated in favor of light-pen::part(sandbox-disclosure-${language}) respectively. disclosure-${language} will be removed in the next major version as its superseded by sandbox-disclosure-${language}. ::part(disclosure) will remain to be able to target all disclosures.

v4.3.0 - 07/04/2025

• Security Fix(light-pen / light-preview): Previously, <iframe> in these 2 components could reach the parent. With this fix, it now has a default set of sandbox settings as follows: allow-downloads allow-forms allow-modals allow-pointer-lock allow-popups allow-presentation allow-scripts
• Bug Fix(light-editor): Fixed a bug with grid setup for soft wrapping
• Feature(light-preview): Added support for src attribute for external URLs.

v4.2.6 - 05/02/2025

• Bug Fix(light-code): Fixed a bug with soft wrapping in light-code
• Bug Fix(light-editor): Fixed a synchronization bug between light-code and light-editor’s textarea

v4.2.5 - 03/11/2025

• Bug Fix(light-editor): Fixed a bug where cursors appeared wrong in <light-editor>

v4.2.4 - 03/07/2025

• Fixed a bug in Safari for being able to select line numbers

v4.2.3 - 03/07/2025

• Fixed a bug in dedent improperly flagging multiple new lines.

v4.2.1 - 01/02/2025

• Bug Fix(light-code): Fixed lines not spanning the full width of the grid.

v4.2.1 - 01/02/2025

• Bug Fix(light-code): Make dedent from slotted tags not suck [#]

v4.2.0 - 11/04/2024

• Styles(light-code): Default line wrapping of <light-code> is now "hard"

v4.1.1 - 11/03/2024

• Bug Fix(light-preview): Fixed a bug in Safari with vertical resizing.

v4.1.0 - 08/03/2024

• Feature(light-preview): Added the after-actions, above-expanded-code, and after-expanded-code slots and parts. [#24]
• Bug Fix(light-preview): now properly listens to changes to unescapeBehavior / unescape-behavior [#24]
• Bug Fix(light-editor): Properly insert new lines. [#25]

v4.0.0 - 08/01/2024

• BREAKING_CHANGE: All components are now scoped under exports/components/<component-name>/<component-name>.js

v3.1.2 - 07/18/2024

• Bug Fix(light-code): wrap="none" properly renamed to wrap="hard" #22
• Bug Fix(light-code): Fixes wrapping in light-editor, and adjusts the wrap values to align with <light-pen> #22
• Bug Fix(light-code) Line highlights now work properly when using wrap="hard" #22
• Bug Fix(light-code): Added cursor syncing due to line numbers obstructing view of text #22

v3.1.1 - 06/01/2024

• Bug Fix(light-code): Fixed a bug that caused LineNumberPlugin to run before the Prism afterTokenize hooks.

• Styles(light-code): <light-code> refactored to use CSS variables for easier initial styling.

• Dependencies: Upgraded Lit and form-associated-helpers

v3.1.0 - 05/28/2024

• Feature: Add src attribute for loading remote content into <light-editor>

• Feature: Added highlighter property to <light-code>, <light-preview>, and <light-editor> for customizing the Prism instance.

• Bug Fix: required is not a proper boolean on <light-editor>

• Styles(light-code): <light-code> (and <light-preview> / <light-editor>) got updates to their default theme and now have a number of syntax tokens to use for easy themeing.

• Docs: Added documentation on how to extend the Prism instance.

v3.0.6 - 04/04/2024

• Bug Fix: <light-editor> now properly scrolls. #15

v3.0.5 - 04/04/2024

• Bug Fix: gutter now behaves appropriately when scrolling on wrap="hard" #14

v3.0.4 - 03/31/2024

• Bug Fix: No longer wipe away state when resizing a <light-preview> #13

v3.0.3 03/28/2024

• Bug Fix: Fixed gutter in <light-code> not extending the entire height of the element.
• Bug Fix: Make <iframe> max-width: 100%; so it doesn’t overflow preview container.

v3.0.2 - 03/11/2024

• Styles: overflow: auto; moved to [part~="base"] in <light-preview>
• Bug Fix: disable-highlight and disable-line-numbers now works as expected in <light-preview>
• Bug Fix: <light-preview> fixes unescapeBehavior attribute to unescape-behavior
• Bug Fix: <light-code> now properly supports wrap="hard".

v3.0.1 - 02/27/2024

• Bug Fix: Properly add sandbox-settings for <light-preview> and <light-pen>

v3.0.0 - 02/26/2024

Bug Fix: <light-preview> now correctly passes the wrap property down to <light-code>

v3.0.0 - 02/27/2024

• BREAKING_CHANGE: The default entrypoint now registers all elements.
• BREAKING_CHANGE: previewCode has changed to previewHtml property and preview-html attribute for <light-preview>.
• Feature: Added lineNumberStart for counting indexes starting at a specific number.
• Feature: code and preview-code attributes are now supported on <light-preview>
• Feature: Added <light-code> for displaying code.
• Feature: Added line numbers to all code displays.
• Bug Fix: <script> tags now properly execute inside of <light-preview> and have the scope of their shadow dom bound.
• Improvement: <light-editor>, <light-code>, and <light-preview> all use <light-code> internally now.
• Improvement: Use declarative shadow DOM and fallback to polyfill in <light-preview>

v2.3.1 - 02/13/2024

• Update form associated package

v2.3.0 - 02/13/2024

• Added form association to <light-editor>
• Added wrap="soft | hard" to <light-preview> and <light-editor>
• Added preserve-whitespace to the <light-pen> to pass down to <light-editor>
• <light-preview> now properly creates a second level shadow dom so the preview’s shadow dom styles don’t leak.

v2.2.0 - 12/03/2023

• Switch to a Prism fork to play nicely with ESM and allow testing.

v2.1.0

• Added initialValue to the <light-editor> to allow for resetting the form input.
• Fixed a bug where we would have Prism running automatically.
• Fixed a bug where <light-pen> was no resetting to initial values.

v2.0.0

• BREAKING_CHANGE: Renamed inline-preview to preview-mode for <light-preview> with options of "iframe" or "shadow-dom"
• BREAKING_CHANGE: Changed underlying highlighting library from Highlight.JS to PrismJS
• BREAKING_CHANGE: <light-editor> and <light-preview> No longer attempt to escape / unescape characters in editors and previews.
• BREAKING_CHANGE: <light-preview> has renamed highlightLanguage property to language. highlight-language attribute has been renamed to language.
• Added <light-disclosure>

v1.2.0

• Added <light-editor>
• <light-pen> now uses <light-editor> under the hood. A number of parts have been moved around for the editor.

v1.1.2

• Don’t use src or srcdoc, return to using iframe.contentWindow.writeln(content) due to fixing some CORS bugs.

v1.1.0

• A number of fixes including allowing <template> elements to be slotted into <light-pen> and <light-preview>

v1.0.2

• fix: issues with > and <

v1.0.1

• fix: allow any HTML Element for templating