Uploading multiple images using NSURLSession

Question

I am trying to upload an array of images the user selects . They are base64 encoded . I am getting a null response from the server . Here is my code below.

for (PHAsset *asset in assets) {

[manager requestImageForAsset:asset  targetSize:PHImageManagerMaximumSize contentMode:PHImageContentModeDefault options:self.requestOptions resultHandler:^void(UIImage *image, NSDictionary *info) {


   NSString *encodeStr = [UIImagePNGRepresentation(image) base64EncodedStringWithOptions:NSDataBase64EncodingEndLineWithCarriageReturn];      

  [images addObject:encodeStr];

   }];
}

I am getting images from delegate using QBImagePickerController . I have a NSMutableDictionary as the body content for NSMutableURLRequest .

[uploadObject setValue:@"32" forKey:@"userid"];        
[uploadObject setValue:TFname.text forKey:@"Name"];        
[uploadObject setObject:images forKey:@"SelectedImages"];        


JSONData = [NSJSONSerialization dataWithJSONObject:uploadObject options:NSJSONWritingPrettyPrinted error:nil];

Here is the NSMutableURLRequest

request = [NSMutableURLRequest requestWithURL:url];

[request setHTTPMethod:@"POST"];

[request setValue:@"JSON" forHTTPHeaderField:@"Content-Type"];

[request setHTTPBody:JSONData];

I am getting a server response code as 500 and a null response from the server . I have tried both NSURLSessionDataTask and NSURLSessionUploadTask. Any help would do good !

`NSURL *url = [NSURL URLWithString:uploadURL];` , `uploadURL = @"www.xxx.com";` This is the url . — user5553647, Aug 23 '16 at 10:51
Image should be upload as multipart form data!! not as base64Encoded string!! — Ketan Parmar, Aug 23 '16 at 10:57
refer [http://stackoverflow.com/questions/24250475/post-multipart-form-data-with-objective-c](http://stackoverflow.com/questions/24250475/post-multipart-form-data-with-objective-c) — Ketan Parmar, Aug 23 '16 at 12:00
can i send multiple images using the method referred above ? — user5553647, Aug 23 '16 at 12:10
Refer [this](http://stackoverflow.com/questions/38631178/uploading-image-to-server-detail-explanation-for-beginner/38695956#38695956) ..It may help — Gokul G, Aug 23 '16 at 12:13
Thanks @Gokul . But I don't seem to get this into my head. Is that multiple images are added to single instance of `NSMutableData` ? — user5553647, Aug 23 '16 at 12:37
Can you make it clear to me , I am appending image data to an instance of `NSMutableData` . This is set as the body content to `NSURLMutableRequest` . Now I'll have to add some 5 key-value pairs which i previous sent as a `NSMutableDictionary` converted as JSON object . Now my question is , how can i give this parameters object as well as images as a single `NSMutableData` object to the request ? — user5553647, Aug 24 '16 at 07:12

score 1 · Answer 1 · answered Aug 24 '16 at 03:54

There's no way to determine whether this code is correct or not without seeing the server-side code. It looks like you're sending the following to the server:

{
  "userid" : "32",
  "Name": "someFilename",
  "SelectedImages": [
      "base64-encoded-data-of-first-image",
      "base64-encoded-data-of-second-image",
      ...
  ]
}

If your server understands how to parse a JSON request body and take fields with those names, then it should work just fine. HOWEVER, it seems unlikely that the format is correct, as you're passing in multiple images with what appears to be single filename.

If you are using existing server code, you need to find out what format it expects the data to be in. If you're writing your own server code, you should probably structure the data more like this:

{
  "userid" : "32",
  "SelectedImages": [
     {
        "name": "firstFilename",
        "data": "base64-encoded-data-of-first-image"
     },
     {
        "name": "secondFilename",
        "data": "base64-encoded-data-of-second-image"
     },
      ...
  ]
}

This doesn't work for me either . The server expects it to be sent the way i did . — user5553647, Aug 24 '16 at 05:46
Either way, the problem is either that you're not sending it in the form the server expects (e.g. are you sure it expects JSON?) or there's a bug on the server side. Your client code is fine. — dgatwood, Aug 24 '16 at 16:50
Correction: Your content type is probably wrong. Try application/json. — dgatwood, Aug 24 '16 at 16:51

score 0 · Answer 2 · answered Sep 09 '16 at 05:11

0

Finally I Found the issue sometime ago .

The problem was with the server side .

answered Sep 09 '16 at 05:11

user5553647

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Uploading multiple images using NSURLSession

2 Answers2