@react-native/codegen

What is @react-native/codegen?

The @react-native/codegen package is a tool used in the React Native ecosystem to generate native code (Java for Android, Objective-C for iOS) from JavaScript. It is primarily used to bridge custom native modules and components in a React Native application, facilitating the communication between JavaScript and native code. This tool automates the process of creating the necessary boilerplate code for native modules, making the development process more efficient and less error-prone.

What are @react-native/codegen's main functionalities?

Generating Native Modules

This feature allows developers to generate the boilerplate code for native modules by specifying the platform (iOS or Android), the path to a schema file (schema.json) that describes the module, and the output directory. The schema file is a JSON file that outlines the structure and types of the native module's methods and properties.

"npx react-native codegen --platform ios/android --schemaPath ./schema.json --outputDir ./output"

Generating Native Components

Similar to native modules, this feature enables the generation of boilerplate code for native components. The process involves specifying a schema file (componentSchema.json) that describes the component's properties and events, allowing for seamless integration of custom native UI components into React Native applications.

"npx react-native codegen --platform ios/android --schemaPath ./componentSchema.json --outputDir ./output"

Other packages similar to @react-native/codegen

react-native-builder-bob

React Native Builder Bob is a tool that helps developers create React Native libraries with support for both native and JavaScript code. While it provides a streamlined process for setting up, building, and publishing libraries, it does not offer the same code generation capabilities for bridging native modules and components as @react-native/codegen.

react-native-create-bridge

React Native Create Bridge is a CLI tool designed to simplify the process of creating native modules and UI components for React Native. It offers a more interactive approach by prompting users for input to generate the necessary boilerplate code. However, it is not as automated or schema-driven as @react-native/codegen, requiring more manual intervention.

README

@react-native/codegen

Installation

yarn add --dev @react-native/codegen

Note: We're using yarn to install deps. Feel free to change commands to use npm 3+ and npx if you like

Testing

To run the tests in this package, run the following commands from the React Native root folder:

• yarn to install the dependencies. You just need to run this once
• yarn jest packages/react-native-codegen.

Changelog

v0.82.0-rc.0

Breaking

• Appearance.setColorScheme: Appearance.setColorScheme no longer accepts a nullable value (a4581ecd8b by @huntie)
• CxxSharedModuleWrapper: Removed CxxSharedModuleWrapper (fafbee2402 by @javache)
• DOM API: Enable DOM APIs in host component refs (2ad845ccb2 by @rubennorte)
• Error Handling: Unhandled promises are now handled by ExceptionsManager.handleException, instead of being swallowed as Logbox Warnings. (c4082c9ce2 by @krystofwoldrich)
• shouldEmitW3CPointerEvents: Migrate shouldPressibilityUseW3CPointerEventsForHover to common private feature flags and remove shouldEmitW3CPointerEvents flag. (fb4587780e by @coado)
• TurboModuleUtils: Remove unused ReactCommon/TurboModuleUtils functions #deepCopyJSIObject and #deepCopyJSIArray (ead669ade3 by @christophpurrer)

Android specific

• Deps: Gradle to 9.0 (7f93b664b4 by @cortinico)
• Image Prefetching: Android: Image Prefetching send ImageResizeMode as enum value (e30f34eda6 by @christophpurrer)
• New Architecture: Remove possibility to newArchEnabled=false in 0.82 (d5d21d0614 by @cortinico)
• reactNativeHost: Throw Exception if ReactApplication.reactNativeHost is not overriden (0d3791ca0a by @mdvacca)
• ViewManagerInterfaces: Migrate ViewManagerInterfaces to kotlin. Some types in code generated ViewManagerInterfaces might differ. e.g. this will start enforcing nullability in parameters of viewManagerInterface methods (e.g. String commands parameters are not nullable, view params are not nullable in any method, etc) (79ca9036d3 by @mdvacca)

iOS Specific

• New Architecture: Removed the opt-out from the New Architecture. (83e6eaf693 by @cipolleschi)

Added

• Animated: Animated.CompositeAnomation is now exposed when using "react-native-strict-api" (024d25794a by @huntie)
• Animated: Allow calling createAnimatedNode without batching (d9d9a49e18 by @zeyap)
• Animated: Allow filter usage with native animated driver. (138d0eb01d by @intergalacticspacehighway)
• API: Expose NativeComponentRegistry API as JavaScript root export (f936780cd5 by @zhongwuzw)
• API: Expose ReactNativeVersion API as JavaScript root export (ec5638abd0 by @huntie)
• Codegen: Added getDebugProps to codegen (e547f466ee by @cipolleschi)
• Pressable: Allow setting blockNativeResponder on Pressable (6e4d23ded2 by @zeyap)
• Yoga/API: Make yoga/Yoga.h an umbrell header (8ed2cee80e by @rudybear)

Android specific

• Build Type: Create a debugOptimized buildType for Android (eb2461c7c9 by @cortinico)
• DevMenu: Add long-press back as an option to open the DevMenu for devices that lack menu & fast-forward. (32d37f03ad by @sbuggay)
• DevTools: DevSupportManager::openDebugger now supports an optional panel param determining the starting panel (7eb3536728 by @huntie)
• DevTools: Adds a landing view parameter to opening RNDT, enabling arbitrary view focus on launch. (635c707eec by @sbuggay)
• HWInput: Channel up/down hardware events. (c2a3e4420e by @sbuggay)
• Manifest: Add support to specify a single Manifest rather than 2 (main/debug) by using the usesCleartextTraffic manifest placeholder which is autoconfigured by RNGP. (d89acc1596 by @cortinico)

iOS specific

• API: Add deprecation message for RCTAppdelegate APIs (d503ea4efc by @cipolleschi)
• New Architecture: Add warning if RCT_NEW_ARCH_ENABLED is set to 0 (7d0bef2f25 by @cipolleschi)

Changed

• Font: Enabled enableFontScaleChangesUpdatingLayout feature flag by default (686d14f1d1 by @j-piasecki)
• Hermes: Changed names of hermes binaries (776fca1e7c by @j-piasecki)
• Metro: Bump Metro to ^0.83.1 (840fd6c83f by @robhogan)
• React: Bumped React to 19.1.1 (ec5a98b1f5 by @cipolleschi)
• Runtime: CDP backend now accepts addBinding and removeBinding methods earlier, before a Runtime exists. (3271e57c75 by @motiz88)
• Typing: Update types for Platform.version (f6ba2dbf3b by @riteshshukla04)
• UIManager: Avoid unnecessary copy of view props map in UIManager::updateShadowTree (5b38bb4745 by @zeyap)

Android specific

• AGP: AGP to 8.12.0 (742ef3d661 by @cortinico)
• DevSupportManager: DevSupport openDebugger() methods now accept a panel: String? param. Frameworks directly implementing DevSupportManager will need to adjust call signatures. (9dba7112cf by @huntie)
• **Kotlin:**Migrated TextAttributeProps to Kotlin. You might need to update your property access to use camelCase instead of Hungarian notation. (fa921b3c7b by @mateoguzmana)
• Kotlin: Migrated ReactBaseTextShadowNode to Kotlin. You might need to update your property access to use camelCase instead of Hungarian notation. (8ccfff9a46 by @mateoguzmana)
• Kotlin: Migrated com.facebook.react.bridge.Arguments to Kotlin. (2534aeaddb by @mateoguzmana)
• Kotlin: Migrate YogaConfig to Kotlin (4d5caef76b by @mateoguzmana)
• Kotlin: Migrate YogaValue to Kotlin (4340dcbae8 by @mateoguzmana)
• Kotlin: Migrate YogaNative to Kotlin (bc54a06fcb by @mateoguzmana)
• Kotlin: Migrate YogaConfigFactory to Kotlin (33ca53d9db by @mateoguzmana)
• Kotlin: Migrate DoNotStrip to Kotlin (35d8086881 by @mateoguzmana)
• Kotlin: Migrate YogaLayoutType to Kotlin (7e461003c6 by @mateoguzmana)
• Kotlin: Migrate LayoutPassReason to Kotlin (db2a9c089c by @mateoguzmana)
• Kotlin: Migrate YogaNodeFactory to Kotlin (40afa75a7c by @mateoguzmana)
• Kotlin: Migrate YogaMeasureOutput to Kotlin (453508ada8 by @mateoguzmana)
• Kotlin: Migrate YogaMeasureFunction to Kotlin (05eddd354e by @mateoguzmana)
• Kotlin: Migrate YogaStyleInputs to Kotlin (001736000f by @mateoguzmana)
• Kotlin: Migrate YogaBaselineFunction to Kotlin (a2eb3b299d by @mateoguzmana)
• Kotlin: Migrate YogaLogger to Kotlin (9c9a39b58e by @mateoguzmana)
• OnBatchCompleteListener: Make OnBatchCompleteListener interface internal (046ff8e58b by @cortinico)
• ReactSurface: Changed return type of ReactSurfaceImpl.view to ReactSurfaceView to align with parameter recived by ReactSurfaceImpl.attachView() (41029d8e91 by @mdvacca)
• TextAttributeProps: Deprecate the field TextAttributeProps.effectiveLineHeight. This field was public but never used in OSS. (ede037ade7 by @cortinico)
• ViewManagers: Changed method arguments names for Core ViewManagers to match the names of ViewManagerInterfaces (e7d9e0d197 by @mdvacca)

Deprecated

• StyleSheet: StyleSheet.absoluteFillObject is deprecated in favor of StyleSheet.absoluteFill (equivalent). (83e19813ff by @huntie)
• Deprecate all the c++ classes not used by interop, or the new architecture. (9539cd2626 by @RSNara)

Android specific

• DevMenu: Remove bridge mode string from React Native Dev Menu title (1c838f32a9 by @sbuggay)
• New Architecture: DefaultDevSupportManagerFactory.create() method used for Old Arch (026e22bb8d by @cortinico)
• New Architecture: Deprecate BridgelessReactContext.getCatalystInstance() method (4583fbe052 by @cortinico)
• New Architecture: Deprecate legacy architecture classes ReactInstanceManager and ReactInstanceManagerBuilder, these classes will be deleted in a future release (fb84932e48 by @mdvacca)
• New Architecture: Depreacate CoreModulesPackage and NativeModuleRegistryBuilder legacy architecture classes, these classes unused in the new architecture and will be deleted in the future (d3bbbd893a by @mdvacca)
• New Architecture: Deprecate Legacy Architecture ViewManagers, these classes are not used as part of the new architecture and will be deleted in the future (da74d5da2c by @mdvacca)
• New Architecture: Deprecate LegacyArchitecture ShadowNode classes included in React Native (07091a9ae8 by @mdvacca)
• New Architecture: Depreacte all LegacyArchitecture classes from the bridge package (c1f7c5e321 by @mdvacca)
• New Architecture: Deprecate LegacyArchitecture class UIManagerProvider (b29b86f275 by @mdvacca)
• New Architecture: Deprecate BridgeDevSupportManager and JSInstance (25c011eb4d by @mdvacca)
• New Architecture: Deprecate NativeModuleRegistry Legacy Architecture class (22e4c25211 by @mdvacca)
• New Architecture: Deprecate subset of LegacyArchitecture classes in com/facebook/react/bridge (78a3ff81eb by @mdvacca)
• New Architecture: Deprecate LegacyArchitecture class FrescoBasedReactTextInlineImageShadowNode (25f466cc4d by @mdvacca)
• New Architecture: Deprecate Legacy Architecture class CallbackImpl (718126fcf0 by @mdvacca)
• New Architecture: Deprecate LegacyArchitecture class JavaMethodWrapper (19a99dd088 by @mdvacca)
• New Architecture: Deprecate Legacy Architecture ShadowNode classes (c4715886a9 by @mdvacca)
• New Architecture: Deprecate LegacyArchitecture UIManagerModules class (85610c8b43 by @mdvacca)
• New Architecture: Deprecate LegacyArchitecture classes from com/facebook/react/uimanager (7f5b2b8f84 by @mdvacca)
• New Architecture: Deprecate LegacyArchitecture classes from package com.facebook.react.uimanager (39d24bade3 by @mdvacca)
• New Architecture: Deprecate LegacyArchitecture classes from LayoutAnimation package (f67078df07 by @mdvacca)
• New Architecture: ReactPackageLogger is not supported in the new architecture and being deprecated (65671108f6 by @mdvacca)

iOS specific

• DevMenu: Remove bridge mode title and description from React Native Dev Menu title (775daf5972 by @sbuggay)
• New Architecture: Deprecate all the objc classes not used by interop, or the new architecture. (70f53ac4ea by @RSNara)

Removed

• New Architecture: Core: Remove legacy components (9c8a4c2297 by @RSNara)

Android specific

• DefaultReactHost: Delete unused DefaultReactHost.getDefaultReactHost() overload (d35ddb5e59 by @cortinico)
• DefaultReactHost: Remove deprecated DefaultReactHost.getDefaultReactHost() overload - part 2 (bda6acf3b0 by @cortinico)
• DefaultReactHost: Remove deprecated DefaultReactHost.getDefaultReactHost() overload - part 1 (474f455a75 by @cortinico)
• Inspector: Removed unused Inspector public class from React Android (cf528526cc by @cortinico)
• JSONArguments: Remove the com.facebook.react.bridge.JSONArguments class (04ae15d99b by @cortinico)
• MessageQueueThreadPerfStats: Deprecated MessageQueueThreadPerfStats API and replaced with stub. (3bf5cb3d0e by @javache)

Fixed

• Accessibility: Fix for setting the default value for accessibility props (586f5ba89c by Vineeth K)
• Accessibility: aria-hidden support for Text, non-editable TextInput and Image (0f39fc3000 by @mdjastrzebski)
• Build: Fixed babel plugin validation error when coverage instrumentation is enabled (191ddc1ec7 by Umar Mohammad)
• Casting: Casting rawValue to int was incorrectly truncating (31b9f10364 by @javache)
• Codegen: Help Codegen find library's package.json if some libraries using exports field in their package.json file and the ./package.json subpath is not explicitly defined (739dfd2141 by @RakaDoank)
• Hermes: Change leftover references to hermes.framework to hermesvm.framework (7f051c5470 by @j-piasecki)
• Performance Panel: Fix typo in Performance.js type checking condition (6caf2dfa38 by @YangJonghun)
• Performance Panel: Add default cases to switch statements in headers (323fe3a5d4 by @NSProgrammer)
• ReactCommon: Bring back ContextContainer::Shared = std::shared_ptr<const ContextContainer> alias (daeb6e99ab by @christophpurrer)
• ReactCommon: Bring back SharedImageManager = std::shared_ptr<ImageManager> alias (4718b35259 by @christophpurrer)
• ReactCommon: Fixed Type Conversion Error in DynamicEventPayload (ff38d59cff by Harini Malothu)
• ReactCommon: Fixed Type Conversion Error in CSSHexColor (2ca88a0069 by @anupriya13)
• TestCallInvoker: Fix memory leak in TestCallInvoker (9f2fbc23e4 by @christophpurrer)

Android specific

• Accessability: Stabilize custom accessibility action IDs to prevent "incompatible action" errors in TalkBack. (626568f9a3 by @leg234-png)
• Determinism: Turned off build IDs for native libraries, fixing issues with reproducibility (4b8dbe7642 by @Rexogamer)
• DevTools: Fix stack trace linkifying failing when using Android emulator and other situations where the device and debugger have different bundle urls (794df48ad6 by @vzaidman)
• Edge to Edge: Fix Dimensions window values on Android < 15 when edge-to-edge is enabled (3b185e4bce by @zoontek)
• Fonts: Update font scale when recreating RootView (5cda3065ce by @j-piasecki)
• Fonts: Fix incorrect positioning of inline view at the end of string when RTL text in LTR container (7f224941bb by @NickGerleman)
• Locale: Use the first available locale instead of the default one to decide isDevicePreferredLanguageRTL (a03780d279 by Kaining Zhong)
• New Architecture: Correctly account for insets on first render of Modals on New Arch (2e76fc8e8e by @cortinico)
• Performance: Fix mounting is very slow on Android by shipping native transform optimizations (c557311ed8 by @cortinico)
• Scroll: Fixed an issue where shadow tree and native tree layouts mismatch at the end of a scroll event (1828c53f85 by @Abbondanzo)
• Start up: Fix wrong default for jsBundleAssetPath on DefaultReactHost (2246e2b82c by @cortinico)

iOS specific

• Build: Fixed using USE_FRAMEWORKS (static/dynamic) with precompiled binaries (e723ca4d6b by @chrfalch)
• Build: Non-UTF8 crashes Info.plist local frameworks (91e69b5d4c by @philipheinser)
• Build: Fixed variable naming error in set_fast_float_config method in react_native_pods.rb (327057fad5 by @eliotfallon213)
• Build: Fix pure cocoapods dynamic framework build (aa4555eaf1 by @cipolleschi)
• Native Modules: Fix concurrent calls into resolve/reject inside native modules (dc879950d1 by @RSNara)
• New Architecture: Fix overriding (xc)framework Info.plist files with RCTNewArchEnabled field (f84514a88b by @msynowski)
• RCTPullToRefreshViewComponentView: Properly initialize the RCTPullToRefreshViewComponentView (27217e8bd6 by @cipolleschi)
• RCTReactNativeFactory: Ask the delegate for getModuleForClass and getModuleInstanceFromClass (85b47afb48 by @cipolleschi)
• ScrollView: Correctly propagate ScrollView props to RefreshControl (09daad27ea by @cipolleschi)
• ScrollView: Make sure that ScrollView recycled refresh control have the right props setup. (21b93d8d7d by @cipolleschi)
• Switch: Fixed a crash when rendering the Switch component (28275a0f7b by @cipolleschi)
• Text: Fix selectable prop not working correctly (f004cd39bc by @iamAbhi-916)
• TextInput: Update TextInput recycling logic to clean up the inputAccessoryView dependency. (eb08f54594 by @ArturKalach)
• TextInput: Fixed TextInput behavior when maxLength={null} is passed (56ad53cb14 by @cipolleschi)
• View: Inline View alignment with lineHeight in Text (6da351a5ed by @intergalacticspacehighway)

Security

• Network: Fixed vulnerability on undici and on-headers (dd00c9055a by @cipolleschi)