#229 add IOS API excludeFromBackupKey

src/index.js

   let respInfo = {}
   let [method, url, headers, body] = [...args]
 
+  // # 241 normalize null or undefined headers, in case nil or null string
+  // pass to native context
+  headers = _.map(headers, (h) =>  h || '');
+
   // fetch from file system
   if(URIUtil.isFileURI(url)) {
     return fetchFile(options, method, url, headers, body)

src/ios.js

     return Promise.reject('RNFetchBlob.previewDocument only supports IOS.')
 }
 
+/**
+ * Set excludeFromBackupKey to a URL to prevent the resource to be backuped to
+ * iCloud.
+ * @param  {string} url URL of the resource, only file URL is supported
+ * @return {Promise}
+ */
+function excludeFromBackupKey(url:string) {
+  return RNFetchBlob.excludeFromBackupKey('file://' + path);
+}
+
 export default {
   openDocument,
   previewDocument

src/ios/RNFetchBlob/RNFetchBlob.m

     }
 })
 
+# pragma mark - exclude from backup key
+
+RCT_EXPORT_METHOD(excludeFromBackupKey:(NSString *)url resolver:(RCTPromiseResolveBlock)resolve rejecter:(RCTPromiseRejectBlock)reject
+{
+    NSError *error = nil;
+    [ [NSURL URLWithString:url] setResourceValue:[NSNumber numberWithBool:YES] forKey:NSURLIsExcludedFromBackupKey error:&error];
+    if(!error)
+    {
+        resolve(@[[NSNull null]]);
+    } else {
+        reject(@"RNFetchBlob could not open document", [error description], nil);
+    }
+    
+})
+
+
 RCT_EXPORT_METHOD(df:(RCTResponseSenderBlock)callback
 {
     [RNFetchBlobFS df:callback];

src/ios/RNFetchBlobFS.m

         
     }];
     
+    
 }
 
 // send read stream chunks via native event emitter