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We're rolling out the first batch of Game UIs right now, and it might take a few days to fully wrap up. If you're already testing the UI comps, we'd love to hear any feedback you've got! 🙏
DocumentationUpgrading

If you’re upgrading OneJS between major versions (via any of the installation methods outlined in the Getting Started guide), you may need to reset some default config files. Here’s the list:

  • package.json
  • tsconfig.json
  • esbuild.mjs
  • postcss.config.js
  • tailwind.config.js

Just delete these from your WorkingDir (by default, that’s {ProjectDir}/App), then run your scene with the ScriptEngine prefab. OneJS will auto-generate fresh versions of those files with the latest defaults. If you’ve made custom changes, be sure to back them up first.

V1 to V2 Upgrade Notes

  • Most of the DOM APIs from V1 still work the same in V2, so you probably won’t need to change much there.
  • The Objects list on ScriptEngine has been replaced with Globals. That means you don’t need to do require("myObj") anymore. You can just use myObj directly in your JS code.
  • If you were using any Jint-specific code, you’ll need to update that to work with PuerTS instead.

V2 ChangeLog

[2025-05-28] v2.2.2 - Misc Improvements

  • Delayed EvalFile(). This ensures the inital <App /> mounting happens after the initial UIDocument load (so that the initial layouts are already calculated).
  • Added an extra “.root” css specificity to generated TW classes.

[2025-05-21] v2.2.1 - Game UIs

Improved some workflows to support the rollout of our game UIs.

To upgrade from a previous version:

  • make sure to update onejs-core and onejs-preact to ^2.0.0
  • The following defaults have changed:
    • postcss.config.js, tailwind.config.js, tsconfig.json
    • input.css, .vscode/tasks.json
  • You can delete them and run scene with ScriptEngine again (be mindful if you have custom changes)

To install OneJS’s Game UIs, you can now run:

npx oj add all

This will work as long as you have a premade-uis.tgz(.bytes) file anywhere in your Assets/ folder. This file is only included in the OneJS Asset Store package.

[2025-04-14] v2.1.15

  • Debugger Support options on ScriptEngine
  • WebApi to support headers
  • 2xl -> xxl so we don’t run into char escaping issues

[2025-03-12] v2.1.14 - Minor Tweaks

[2025-03-10] v2.1.13 - Bugfixes and Improvements

onejs/math is now available! See onejs-core repo for more info.

  • Better custom UIElement Events handling
  • Normalized Path in ScriptEngine.GetFullPath()
  • EngineHost.subscribe() improvements
  • Better uss class name escaping
  • Many Editor UI improvements

[2025-01-23] v2.1.9 - Improvements to Bundler and DTSGen

  • Many updates on the npm modules (onejs-core, onejs-preact, onejs-comps, etc)
  • Backends MenuItems
  • Removed BaseEditor override
  • Bundler rewrite
  • DTSGen improvements
  • 2021.3 compatibility
  • Fixed puerts reimporting issue
  • Various EditorScriptEngine improvements
  • Use “Assembly-CSharp” by default for DTSGenerator
  • EditorEngineHost refactor
  • Codegen: accomodate for Nullable types
  • EngineHost Refactor

[2024-12-08] v2.1.7 - Minor Tweak

  • Added a global.d.ts by default

[2024-12-02] v2.1.6 - Preparation for Editor UI

We’re releasing this now, ahead of the Editor UI update (expected in a couple of weeks), as it includes significant improvements and bug fixes that are worth rolling out early.

If you are updating an existing project, make sure to also bump the onejs-core package to ^1.0.6 in your package.json.

  • Added WebApi from V1
  • requestAnimationFrame() bugfix (Thx @Kodra)
  • DomStyle.GetLength() bugfix
  • Use min/max for gradientrect
  • Added support for global namespace in DTSGenerator
  • onejs-core dependency bumped to ^1.0.6
  • Many more bugfixes and improvements in onejs-core and onejs-preact

(Most of the Editor UI code are actually in. However, we’ll use the next release to get into the details.)

[2024-10-01] v2.0.26 - OneJS V2 🥳🎉

Major Changes

  • Switched from Jint to Puerts as the JavaScript engine

    • Provides 3 backends: QuickJS, V8, and NodeJS
    • Significantly improved performance (20x to 100x faster)
    • Better memory management with static wrappers and blittable optimizations

  • Adopted ESBuild workflow

    • Bundles everything into a single file for easier deployment
    • Automatic handling of node modules
    • Experimental support for Custom Editor/Inspector UI

New Features

  • Support for node modules and npm packages
  • Improved TypeScript definition generation
  • Experimental Custom Editor UI support

Workflow Improvements

  • Quick backend switching with npm run switch
  • Enhanced interoperability between C# and JavaScript

Other Enhancements

  • Updated ScriptEngine component with new interop settings
  • Streamlined global variable exposure from C# to JavaScript
  • Improved overall stability and performance

V1 ChangeLog

[2024-07-08] v1.6.13 - Preact 10.21

  • Updated Preact to 10.21
  • CultureInfo.InvariantCulture fix for HexMatchToRgba()
  • Add AddRuntime* APIs for ScriptEngine

[2024-02-08] v1.6.10 - Bugfixes and Improvements

OneJS V2 is coming! Get in our Discord server and private repo to follow the progress.

  • Changed ScriptEngine’s LateUpdate() to Update() to fix Task resolution error
  • DPIAdjuster improvements
  • Added checkEquality option to EventfulPropertyAttribute
  • Exposed EngineHost on ScriptEngine
  • Tailwind 4-comp hex color fix
  • ScriptEngine OnEnable & OnDisable support
  • useCapture support for addEventListener and removeEventListener
  • Global host and interop objects with event subscription function (#12)
  • Improved CommonJS path resolver (#11)

[2023-10-22] v1.6.8

  • Cyclic error fix for preact falsey check in Hookstate
  • TSDefConverter moved to using UI Toolkit instead of IMGUI (credit to @iDevelopThings)
  • Various Jint tweaks (RunAvailableContinuations & UnwrapIfPromise)
  • Updated Jint with rest/spread bug fix
  • Fixed the # char bug for TW classes
  • Added _includeOverriddenMembers for TSDefConverter
  • Fixed OpenDir for Linux

[2023-09-09] v1.6.7

  • Auto-reimport uss after generation (Tailwind)
  • useEventfulState() forceUpdate() regression fix

[2023-08-31] v1.6.6 - Stability and Misc Additions

  • Updated Jint to [beta-2050]
  • jsx-runtime support
  • OnPreprocessBuild now accommodates when there’s no scene listed in the build settings
  • Added comps sample scene
  • Added GradientTextureFill Job example
  • Added onEngineDestroy
  • Added webapi.getImage()
  • Added OnInitOptions to ScriptEngine
  • Dom.addEventListener now go through all loaded assemblies
  • Fixed regression in InitAllUIElementEvents()
  • Added TagTypeResolver to ScriptEngine
  • JSON module import
  • Added default tasks.json for vscode
  • Added EventfulPropertyAttribute and corresponding source generator
  • Added ValueTuple check in TSDefConverter

[2023-07-03] v1.6.4 - Comp Library and More

  • Added a new Component Library under ScriptLib/onejs/comps. These are inspired by HeadlessUI.
    • Please see the v1.6 Docs for more information.
  • ScriptLib folder now will contain the .ts files. This is to make it easier to refer to the TS implementation instead of the compiled JS.

[2023-05-30] v1.6.1 - Major Tailwind Rework

[2023-04-23] v1.5.9 - Quite a bit of QoL stuff, Tweaks, and Bugfixes

  • Added more CLR exception handling logging

  • VisualElementExts ForceUpdate()

  • Preact-Jint Cyclic ref error fix

  • Added array type mapping for TSDefConverter

  • Added public properties for ScriptEngine option fields

  • Added _logRedundantErrors to ScriptEngine

  • BuildProcessor bugfix for Cloudbuild @mattehr

  • Improved addEventListener and removeEventListener to allow multiple callbacks on the same event

  • Jint Engine tweak: MemberNameComparer = StringComparer.Ordinal

  • Color processor fix

  • More fields added to Image tag (jsx def)

  • Added unitySliceScale support (new in Unity 2022.2)

  • [StyleProcessor] Check for all falsy values instead of just null

  • forceUpdate() in useEventfulState

  • Added ref support for styled comp

  • Added memo to preact/compat

[2023-03-04] v1.5.7 - Minor Tweaks and Bugfixes

  • Better VectorAPI version check
  • .boxedValue alternative (for Unity 2021.3)
  • Auto-create directory for player workingDir

[2023-02-18] v1.5.5 - Internal Code Improvements

Online documentation was revamped! Check it out at https://onejs.com/  There is now a new comprehensive Tutorial101.

  • Cloud Build support (some internal changes to Bundler)
  • Runtime USS errors are now properly handled (No longer need to reload scene)
  • Offline Doumentation.pdf revamped
  • Many minior tweaks and bugfixes

[2023-01-26] v1.5.1 - Getting ready for VanillaBox

  • New custom Editors for ScriptEngine, Bundler, and LiveReload. Removed dependency on NaughtyAttributes.
  • Some internal changes done to support the launch of VanillaBox
  • Removed lib.dom.d.ts from the default Typescript typings
  • Made WorkingDir more configurable per ScriptEngine. This also makes having multiple ScriptEngines easier.
  • Replaced FrontLoader and ImageLoader with the resource global variable
  • Moved OneJSBuildProcessor functionality to Bundler
  • Removed Extract ScriptLib On Start option as this is replaced by the ScriptsBundle

[2023-01-04] v1.4.5 Misc

  • TSDefConverter now supports Jint syntax for events (“add_” and “remove_”).
  • Added a new Sample (CharManSample)

[2022-12-25] v1.4.4 Misc

  • Bugfix for clearInterval() not working inside the queued action
  • classnames added
  • VectorAPI check for sample scene

[2022-12-15] v1.4.3 Built-in Styled Components and Emotion APIs

  • Implemented onejs/styled which includes both styled-components and emotion APIs.
  • backgroundImage Style prop now also accepts Sprite objects in addition to string paths and Texture objects.
  • Reverted default Trickledown.
  • ScriptEngine.Objects list will now accept any UnityEngine.Object, not just MonoBehaviours.

[2022-11-08] v1.3.5 - useEventfulState()

  • Implemented useEventfulState()
  • Fixed inconsistent timing between performance.now() and requestAnimationFrame()
  • Keep existing unity-* classnames intact for stock controls
  • Added IsByRef check in TSDef Converter
  • Updated Preact Signals to latest version
  • Path Resolver tweak

[2022-10-13] v1.3.3a - Bundler Changes

  • Added user-defined sub-directories for the bundler to ignore during runtime updates

[2022-10-08] v1.3.3 - Async/await support

  • Async/await are now supported in OneJS scripts

  • Preact Signals are also now fully supported

  • Changed QueuedActions to use PriorityQueue

  • Added RadioButton and RadioButtonGroup TS Defs and sample usage

  • Fixed issue with relative path loading same modules more than once

  • Fixed OneJSBuildProcessor+OnPreprocessBuild _ignoreList issue

  • NetSync: Have Server also Broadcast

  • Tailwind ParseColor bugfix @LordXyroz

[2022-09-15] v1.3.1a - ExCSS.Unity fix

  • Patched ExCSS.Unity.dll so it doesn’t cause conflicts with other Unity packages

[2022-09-13] v1.3.1 - Minor Bug Fixes

  • Fixed turning Live Reload off for Standalone builds
  • Add Navigation Events to the TS definitions
  • Better UglifyJS error handling
  • Adds support for chaining pseudo selectors @Walrusking16
  • Tag lookup fix, Dom compliance and ListView example @Sciumo

[2022-09-01] v1.3.0 - Runtime CSS

You are now able to load CSS strings at runtime via document.addRuntimeCSS(). See https://onejs.com/runtimecss  for more information.

  • Runtime CSS
  • Updated Jint to latest
  • Copy to Clipboard for TSDefConverter (credit to @Sciumo)
  • Added node_modules to JSPathResolver
  • _engine.ResetConstraints() in Update Loop
  • Action queues without coroutines
  • setInterval

[2022-07-10] v1.2.1 - Minor features and bugfixes

  • Implemented onValueChanged for UI Toolkit controls
  • Fixed __listeners Linux slowdown
  • GameObject Extensions AddComp(), GetComp(), and FindType() fixes
  • UIElementsNativeModule handling for 2022.2 and later

[2022-06-24] v1.2.0 - WorkingDir Rework

You are now able to keep all your scripts under {ProjectDir}/OneJS. And the scripts will be automatically bundled into{persistentDataPath}/OneJS for Standalone builds.

  • Added a Bundler component that is responsible for extracting scripts.
  • Added OneJSBuildProcessor ScriptableObject that is responsible for packaging scripts (for Standalone builds).
    • This is generally automatic as it uses OnPreprocessBuild
    • It also provides glob ignore patterns for things you don’t want to include in the bundle.
  • Added [DefaultExecutionOrder] for various components.
  • Added an extra option (Poll Standalone Screen) on the Tailwind component to allow you to also watch for screen changes for standalone builds.

[2022-06-19] v1.1.2 - Bugfixes

  • Fixed various preact cyclic reference errors
  • Fixed preact diff bug (missing parentNode)
  • Fixed Tailwind StyleScale regression in 2021.3

[2022-06-08] v1.1.1 - Flipbook and more Tailwind support

Newly Added:

  • Flipbook Visual Element
  • Negative value support for Tailwind

Minor Bug fixes:

  • Opacity bugfix
  • Preact useContext bugfix
  • Preact nested children bugfix

[2022-05-26] v1.1.0 - Tailwind and Multi-Device Live Reload

New Features:

  • Tailwind
  • Multi-Device Live Reload
  • USS transition support in JSX

Other Notables:

  • Completely reworked Live Reload’s File watching mechanism to conserve more CPU cycles. Previously it was using FileSystemWatcher (poor performance when watching directories recursively).
  • New GradientRect control (allows linear gradients with 4 corners, demo’ed in the fortnite ui sample)

Minor Bug fixes:

  • Fixed Double to Single casting error during Dom.setAttribute
  • Fixed object[] casting during Dom.setAttribute
  • Fixed unityTextAlign style Enum bug
  • Fixed overflow style Enum bug
  • Fixed a bunch of setStyleList bugs

[2022-05-16] v1.0.0 - Initial Release

  • Full Preact Integration with 1-to-1 interop with UI Toolkit
  • Live Reload
  • C# to TS Def converter
Styled EmoDeployment