iOS custom native module

README.txt

#FOUND ON
https://www.reactnative.guide/16-custom-native-modules/16.2-ios-native-module.html

Component.js

import React from "react";
import {
  NativeModules
} from "react-native";

export default class Component extends React.Component {
  componentDidMount() {
    //calling native method
    NativeModules.Device.getDeviceName((err ,name) => {
       console.log(err, name);
    });
  }
  return(){
    render(
      ...
    )
  }
}
  

Device.h

#import <Foundation/Foundation.h>
#import <React/RCTBridgeModule.h>
#import <React/RCTEventEmitter.h>

NS_ASSUME_NONNULL_BEGIN

@interface Device : RCTEventEmitter <RCTBridgeModule>

@end

NS_ASSUME_NONNULL_END

Device.m

#import "Device.h"

@implementation Device
RCT_EXPORT_MODULE();

- (dispatch_queue_t)methodQueue
{
  return dispatch_get_main_queue();
}

- (NSArray<NSString *> *)supportedEvents
{
  return @[@""];
}

//exports a method getDeviceName to javascript
RCT_EXPORT_METHOD(getDeviceName:(RCTResponseSenderBlock)callback){
  @try{
   NSString *deviceName = [[UIDevice currentDevice] name];
   callback(@[[NSNull null], deviceName]);
 }
 @catch(NSException *exception){
   callback(@[exception.reason, [NSNull null]]);
 }
}


@end