#Native Integration

After codegen, implement the generated delegate interface in your host app and register it before JavaScript uses the module.

#Pre-Requisite:

Ensure that the BrownfieldNavigation.xcframework is linked to the native host app. If you ran npx brownfield package:ios the generated frameworks should be under ios/.brownfield folder.

#Android

#1) Implement BrownfieldNavigationDelegate

Implement the generated delegate methods in your host Activity (or another class with access to navigation context):

import android.content.Intent
import androidx.appcompat.app.AppCompatActivity
import com.callstack.nativebrownfieldnavigation.BrownfieldNavigationDelegate

class MainActivity : AppCompatActivity(), BrownfieldNavigationDelegate {
  override fun navigateToSettings() {
    startActivity(Intent(this, SettingsActivity::class.java))
  }

  override fun navigateToReferrals(userId: String) {
    startActivity(
      Intent(this, ReferralsActivity::class.java)
        .putExtra(ReferralsActivity.EXTRA_USER_ID, userId)
    )
  }
}

#2) Register the delegate during startup

Register before any React Native screen can call BrownfieldNavigation.*:

import android.os.Bundle
import com.callstack.nativebrownfieldnavigation.BrownfieldNavigationManager

override fun onCreate(savedInstanceState: Bundle?) {
  super.onCreate(savedInstanceState)
  BrownfieldNavigationManager.setDelegate(this)
  // Initialize React Native host
}

#iOS

#1) Implement BrownfieldNavigationDelegate

import BrownfieldNavigation
import SwiftUI
import UIKit

public final class RNNavigationDelegate: BrownfieldNavigationDelegate {
  public func navigateToSettings() {
    present(SettingsScreen())
  }

  public func navigateToReferrals(_ userId: String) {
    present(ReferralsScreen(userId: userId))
  }

  private func present<Content: View>(_ view: Content) {
    DispatchQueue.main.async {
      let hostingController = UIHostingController(rootView: view)
      UIApplication.shared.topMostViewController()?
        .present(hostingController, animated: true)
    }
  }
}

#2) Register the delegate at app startup

import BrownfieldNavigation

@main
struct BrownfieldAppleApp: App {
  init() {
    BrownfieldNavigationManager.shared.setDelegate(
      navigationDelegate: RNNavigationDelegate()
    )
  }
}

#Lifecycle Requirements

• Register delegate before rendering JS that might call the module.
• Keep navigation on main/UI thread.
• Re-register delegate if your host object is recreated.
• Treat missing delegate as a startup bug: runtime calls require a registered delegate.

#Troubleshooting

• Method added in TS but not visible natively: rerun codegen and rebuild.
• Calls crash on app launch: verify delegate registration happens before RN route rendering.
• Wrong screen opens: check native delegate method wiring and params mapping.