iOS Upload multiple files at once

Question

Is it possible to upload two (or more) files in only one request??

I've been trying to do so with NSMutableURLRequest and NSURLConnection but no success so far, and I have found no convincing answers online.

It's easy to upload a single file (using code from here) but the HTML Specs mention that when uploading more than one file you have to embed a multipart/mixed header inside the multipart/form-data, and the files to be uploaded within that multipart/mixed header.

The problem with the code linked above is that the one file that is being uploaded has it's Content-Disposition set to "form-data" (I guess that means that the single file is "all" of the form's data?) which I think leaves "no room" to attach another file. Please correct me if i'm wrong.

Thanks.

Answer 1

EDIT:

The file data you are uploading should be encoded using Base64; you can do that by means of NSData+Base64 and then use:

[body appendData:[imageData1 base64EncodedString];

to send the file data, whereby I assume that imageData1 was defined as:

NSData* imageData = UIImagePNGRepresentation(image);

and image is a UIImage.

OLD ANSWER:

This is an example coming from the HTML 4.0.1 standard (very end of the document):

Content-Type: multipart/form-data; boundary=AaB03x

--AaB03x
Content-Disposition: form-data; name="submit-name"

Larry
--AaB03x
Content-Disposition: form-data; name="files"
Content-Type: multipart/mixed; boundary=BbC04y

--BbC04y
Content-Disposition: file; filename="file1.txt"
Content-Type: text/plain

... contents of file1.txt ...
--BbC04y
Content-Disposition: file; filename="file2.gif"
Content-Type: image/gif
Content-Transfer-Encoding: binary

...contents of file2.gif...
--BbC04y--
--AaB03x--

Notice that the files are listed all together in a multipart/mixed list.

So you can try with the code:

//-- new part in multipart/form-data
[body appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[@"Content-Disposition: form-data; name=\"files\" dataUsingEncoding:NSUTF8StringEncoding]];

//-- new multipart/mixed
[body appendData:[[NSString stringWithFormat:@"multipart/mixed; boundary=%@", mixedBoundary] dataUsingEncoding:NSUTF8StringEncoding]];

[body appendData:[[NSString stringWithFormat:@"Content-Disposition: file; filename=\"%@\"\r\n", FileParamConstant1] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithString:@"Content-Type: image/jpeg\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:imageData1];
[body appendData:[[NSString stringWithFormat:@"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];


[body appendData:[[NSString stringWithFormat:@"--%@\r\n", mixedBoundary] dataUsingEncoding:NSUTF8StringEncoding]];

[body appendData:[[NSString stringWithFormat:@"Content-Disposition: file; filename=\"%@\"\r\n", FileParamConstant2] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithString:@"Content-Type: image/jpeg\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:imageData2];
[body appendData:[[NSString stringWithFormat:@"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];

Take care of changing the filename and name attributes and it should work.