RNS3Uploader.h

//
//  RNS3Uploader.h
//  Squad
//
//  Created by Dan Horrigan on 10/6/15.
//  Copyright © 2015 Tackk. All rights reserved.
//

#import <Foundation/Foundation.h>
#import "RCTBridgeModule.h"

@interface RNS3Uploader : NSObject <RCTBridgeModule>

@end

RNS3Uploader.m

//
//  RNS3Uploader.m
//  Squad
//
//  Created by Dan Horrigan on 10/6/15.
//  Copyright © 2015 Tackk. All rights reserved.
//

#import "RNS3Uploader.h"
#import <MobileCoreServices/MobileCoreServices.h>
#import <CommonCrypto/CommonCrypto.h>
#import <AWSS3/AWSS3.h>

@implementation RNS3Uploader

RCT_EXPORT_MODULE();

RCT_EXPORT_METHOD(upload:(NSString *)filename
                  bucket:(NSString *)bucket
                     key:(NSString *)photoKey
                resolver:(RCTPromiseResolveBlock)resolve
                rejecter:(RCTPromiseRejectBlock)reject)
{
  dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
    AWSS3TransferManagerUploadRequest *uploadRequest = [AWSS3TransferManagerUploadRequest new];
    uploadRequest.body = [NSURL fileURLWithPath:filename];
    uploadRequest.key = photoKey;
    uploadRequest.contentType = [self mimeTypeForFileAtPath:filename];
    uploadRequest.bucket = bucket;
    uploadRequest.ACL = AWSS3ObjectCannedACLPublicRead;
    [self doUpload:uploadRequest key:photoKey resolver:resolve rejecter:reject];
  });
}



- (void)doUpload:(AWSS3TransferManagerUploadRequest *)uploadRequest
           key:(NSString *)photoKey
      resolver:(RCTPromiseResolveBlock)resolve
      rejecter:(RCTPromiseRejectBlock)reject
{
  AWSS3TransferManager *transferManager = [AWSS3TransferManager defaultS3TransferManager];

  [[transferManager upload:uploadRequest] continueWithBlock:^id(AWSTask *task) {
    if (task.error) {
      reject([@(task.error.code) stringValue], task.error.localizedDescription, task.error);
    } else if (task.exception) {
      NSMutableDictionary *errorInfo = [NSMutableDictionary dictionary];
      errorInfo[NSLocalizedDescriptionKey] = [NSString stringWithFormat:@"An exception occurred while uploading the photo: %@", task.exception.name];
      if (task.exception.reason) {
        errorInfo[NSLocalizedFailureReasonErrorKey] = task.exception.reason;
      }
      NSError *error = [NSError errorWithDomain:@"com.test" code:100 userInfo:errorInfo];
      reject([@(error.code) stringValue], error.localizedDescription, error);
    } else if (task.cancelled) {
      NSDictionary *uploadInfo = @{NSLocalizedDescriptionKey: NSLocalizedString(@"Operation cancelled.", nil)};
      NSError *error = [NSError errorWithDomain:@"com.test" code:100 userInfo:uploadInfo];
      reject([@(error.code) stringValue], error.localizedDescription, error);
    }

    if (task.result) {
      resolve(photoKey);
    }

    return nil;
  }];
}


- (NSString*) mimeTypeForFileAtPath: (NSString *)path
{
  if (![[NSFileManager defaultManager] fileExistsAtPath:path]) {
    return nil;
  }

  CFStringRef UTI = UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, (__bridge CFStringRef)[path pathExtension], NULL);
  CFStringRef mimeType = UTTypeCopyPreferredTagWithClass (UTI, kUTTagClassMIMEType);
  CFRelease(UTI);
  if (!mimeType) {
    return @"application/octet-stream";
  }
  return (__bridge NSString *)mimeType;
}

@end

usage.js

import React from 'react-native';
const { NativeModules: { RNS3Uploader } } = React;

// In some component
RNS3Uploader.upload(filePathToUpload, s3Bucket, s3Key);