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.