Нативные модули в React Native: bridging между JS и Native

1// android/app/src/main/java/com/app/BatteryModule.kt
2package com.app
3
4import android.content.Context
5import android.os.BatteryManager
6import com.facebook.react.bridge.ReactApplicationContext
7import com.facebook.react.bridge.ReactContextBaseJavaModule
8import com.facebook.react.bridge.ReactMethod
9import com.facebook.react.bridge.Promise
10
11class BatteryModule(reactContext: ReactApplicationContext) :
12    ReactContextBaseJavaModule(reactContext) {
13
14    override fun getName(): String = "BatteryModule"
15
16    @ReactMethod
17    fun getBatteryLevel(promise: Promise) {
18        val batteryManager = reactApplicationContext
19            .getSystemService(Context.BATTERY_SERVICE) as BatteryManager
20        val level = batteryManager.getIntProperty(
21            BatteryManager.BATTERY_PROPERTY_CAPACITY
22        )
23        promise.resolve(level.toDouble())
24    }
25}

1// android/app/src/main/java/com/app/BatteryPackage.kt
2package com.app
3
4import com.facebook.react.ReactPackage
5import com.facebook.react.bridge.NativeModule
6import com.facebook.react.bridge.ReactApplicationContext
7import com.facebook.react.uimanager.ViewManager
8
9class BatteryPackage : ReactPackage {
10    override fun createNativeModules(
11        reactContext: ReactApplicationContext
12    ): List<NativeModule> {
13        return listOf(BatteryModule(reactContext))
14    }
15
16    override fun createViewManagers(
17        reactContext: ReactApplicationContext
18    ): List<ViewManager<*, *>> {
19        return emptyList()
20    }
21}

1// ios/BatteryModule.swift
2import Foundation
3import React
4
5@objc(BatteryModule)
6class BatteryModule: NSObject {
7
8  @objc static func requiresMainQueueSetup() -> Bool {
9    return false
10  }
11
12  @objc func getBatteryLevel(
13    _ resolve: @escaping RCTPromiseResolveBlock,
14    rejecter reject: @escaping RCTPromiseRejectBlock
15  ) {
16    UIDevice.current.isBatteryMonitoringEnabled = true
17    let level = UIDevice.current.batteryLevel
18    if level < 0 {
19      reject("ERROR", "Battery info unavailable", nil)
20    } else {
21      resolve NSNumber(value: level * 100)
22    }
23  }
24}

1// ios/BatteryModule.m
2#import <React/RCTBridgeModule.h>
3
4@interface RCT_EXTERN_MODULE(BatteryModule, NSObject)
5
6RCT_EXTERN_METHOD(getBatteryLevel:
7                  (RCTPromiseResolveBlock)resolve
8                  rejecter:(RCTPromiseRejectBlock)reject)
9
10@end

1import { NativeModules } from 'react-native';
2const { BatteryModule } = NativeModules;
3
4async function checkBattery() {
5  try {
6    const level = await BatteryModule.getBatteryLevel();
7    console.log('Battery:', level + '%');
8  } catch (error) {
9    console.error('Battery error:', error);
10  }
11}

1class MapView(reactContext: ReactApplicationContext) :
2    SimpleViewManager<MapView>() {
3
4    override fun getName(): String = "MapView"
5
6    override fun createViewInstance(context: ThemedReactContext): MapView {
7        return MapView(context)
8    }
9
10    @ReactProp(name = "zoom")
11    fun setZoom(view: MapView, zoom: Int) {
12        view.setZoom(zoom.toFloat())
13    }
14}

1// NativeBattery.ts
2import type { TurboModule } from 'react-native';
3import { TurboModuleRegistry } from 'react-native';
4
5export interface Spec extends TurboModule {
6  getBatteryLevel(): Promise<number>;
7}
8
9export default TurboModuleRegistry.getEnforcing<Spec>('BatteryModule');