KOTLIN.md

Kotlin

React Native Brownfield provides first-class support for Kotlin.

API Reference

ReactNativeBrownfield

You can import the object from:

import com.callstack.reactnativebrownfield.ReactNativeBrownfield

---

Statics:

initialize

A function used to initialize a React Native Brownfield singleton. Keep in mind that it doesn't load React Native bundle.

Params:

Param	Required	Type	Description
application	Yes	Application	Main application.
rnHost	No*	ReactNativeHost	An instance of ReactNativeHost.
packages	No*	List<ReactPackage>	List of your React Native Native modules.
options	No*	HashMap<String, Any>	Map of initial options. Options listed below.

• • Those fields aren't itself required, but at least one of them is. See examples below.

Available options:

• useDeveloperSupport: Boolean - Flag to use dev support.
• packages: List<ReactPackage> - List of your React Native Native modules.
• mainModuleName: String - Path to react native entry file.

Examples:

import com.callstack.reactnativebrownfield.ReactNativeBrownfield

val mReactNativeHost = object : ReactNativeHost(application) {
  override fun getUseDeveloperSupport(): Boolean {
    return BuildConfig.DEBUG
  }

  override fun getPackages(): List<ReactPackage> {
    return listOf<ReactPackage>(PackageList(this).getPackages())
  }

  override fun getJSMainModuleName(): String {
    return "index"
  }
}

ReactNativeBrownfield.initialize(this, mReactNativeHost)

val packages = PackageList(this).getPackages()

ReactNativeBrownfield.initialize(this, packages)

val packages = PackageList(this).getPackages()
val options = hashMapOf<String, Any>(
  "packages" to packages, 
  "mainModuleName" to "example/index"
)

ReactNativeBrownfield.initialize(this, options)

---

shared

A singleton that keeps an instance of ReactNativeBrownfield object.

Examples:

ReactNativeBrownfield.shared

---

Properties:

Property	Type	Default	Description
reactNativeHost	ReactNativeHost	null	An instance of ReactNativeHost.

---

Methods:

startReactNative

Starts React Native, produces an instance of React Native. You can use it to initialize React Native in your app.

Params:

Param	Required	Type	Description
startReactNative	No	(loaded: boolean) -> Unit	Callback invoked after JS bundle is fully loaded.

Examples:

ReactNativeBrownfield.shared.startReactNative()

ReactNativeBrownfield.shared.startReactNative {
  Log.d("loaded", "React Native loaded");
}

---

createView

Creates a React Native view with a given module name. It automatically uses an instance of React Native created in startReactNative method. This is useful when embedding React Native views directly in your native layouts or Jetpack Compose UI.

Params:

Param	Required	Type	Description
context	Yes	Context	Android context to create the view
activity	No	FragmentActivity	Activity hosting the view, used for lifecycle management
moduleName	Yes	String	Name of React Native component registered to AppRegistry
launchOptions	No	Bundle	Initial properties to be passed to React Native component

Returns: FrameLayout - A view containing the React Native component.

Examples:

// In a Fragment or Activity
val reactView = ReactNativeBrownfield.shared.createView(
  context,
  activity,
  "ReactNative"
)
container.addView(reactView)

// With Jetpack Compose
AndroidView(
  factory = { context ->
    ReactNativeBrownfield.shared.createView(context, fragmentActivity, "ReactNative")
  },
  modifier = Modifier.fillMaxSize()
)

---

ReactNativeFragment

An fragment rendering ReactRootView with a given module name. It automatically uses a instance of React Native created in startReactNative method. It works well with exposed JavaScript module. All the lifecycles are proxied to ReactInstanceManager. It's the simplest way to embed React Native into your navigation stack.

import com.callstack.reactnativebrownfield.ReactNativeFragment

---

Statics:

createReactNativeFragment

Creates a Fragment with ReactNativeActivity, you can use it as a parameter in the startActivity method in order to push a new activity with embedded React Native.

Params:

Param	Required	Type	Description
moduleName	Yes	String	Name of React Native component registered to AppRegistry.
initialProps	No	Bundle || HashMap<String, *> || ReadableMap	Initial properties to be passed to React Native component.

Examples:

ReactNativeFragment.createReactNativeFragment("ReactNative")

val bundle = Bundle()
bundle.putInt("score", 12)

ReactNativeFragment.createReactNativeFragment("ReactNative", bundle)

val map = hashMapOf<String, *>("score" to 12)

ReactNativeFragment.createReactNativeFragment("ReactNative", map)

val map = WritableMap()
map.putInt("score", 12)

ReactNativeFragment.createReactNativeFragment("ReactNative", map)

---

Example

You can find an example app here.