A guide on how to efficiently retrieve a string within a function in a native module in a React Native

Question

A guide on how to efficiently retrieve a string within a function in a native module in a React Native

I'm currently tackling a function related to the native elements of iOS that is coded in Objective-C,

My goal is to create a method that will output a string in Objective-C,

However, I've hit a roadblock while trying to implement this method:

The Objective-C method selector is expected

,

Here's the snippet of my code:

RCT_EXPORT_METHOD((NSString *)getName)
{
  return "Sammeme";
}
@end

If there's anyone out there with experience in iOS development who could offer some guidance on solving this issue, I would greatly appreciate it.

Thank you!

javascript android ios objective-c react-native

Answer 1

Answer №1

When working in your Implementation file and utilizing the RCT_EXPORT_METHOD, there are two options to return a result: either through a promise or a callback. Personally, I prefer using a promise:

RCT_EXPORT_METHOD(returnStringFromNativeModule:(RCTPromiseResolveBlock)resolve
                  rejecter:(RCTPromiseRejectBlock)reject) {
    resolve(@"Here is the value being sent back from a Native Module");
}

In your React Native script, this is how you would execute your method:

import { NativeModules } from 'react-native';


const { myNativeModule } = NativeModules;
const myString = await myNativeModule.returnStringFromNativeModule();

Answer 2

When working in your Implementation file and utilizing the RCT_EXPORT_METHOD, there are two options to return a result: either through a promise or a callback. Personally, I prefer using a promise:

RCT_EXPORT_METHOD(returnStringFromNativeModule:(RCTPromiseResolveBlock)resolve
                  rejecter:(RCTPromiseRejectBlock)reject) {
    resolve(@"Here is the value being sent back from a Native Module");
}

In your React Native script, this is how you would execute your method:

import { NativeModules } from 'react-native';


const { myNativeModule } = NativeModules;
const myString = await myNativeModule.returnStringFromNativeModule();

A guide on how to efficiently retrieve a string within a function in a native module in a React Native

Answer №1

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