Upload multiple files using http POST

Question

I am having a problem uploading files with FTP from my iPhone app.

I am sending an HTTP POST request to my webservice with all the necessary parameters. I am sending two files, one is an image, and the second is audio. The image is being uploaded, but the audio isn't. When I trace my web service it only shows the image field as an uploaded file. It's not showing that the audio is also there.

My code is:

NSString *urlString = [NSString stringWithFormat:ADD_LEAD_API_URL];

NSMutableURLRequest *postRequest =  [NSMutableURLRequest requestWithURL:[NSURL URLWithString:urlString]];



// change type to POST (default is GET)
[postRequest setHTTPMethod:@"POST"];


// just some random text that will never occur in the body
NSString *stringBoundary = @"0xKhTmLbOuNdArY---This_Is_ThE_BoUnDaRyy---pqo";

// header value
NSString *headerBoundary = [NSString stringWithFormat:@"multipart/form-data; boundary=%@",stringBoundary];

// set header
[postRequest addValue:headerBoundary forHTTPHeaderField:@"Content-Type"];

// create data
NSMutableData *postBody = [NSMutableData data];



[postBody appendData:[[NSString stringWithFormat:@"--%@\r\n", stringBoundary] dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[[NSString stringWithString:@"Content-Disposition: form-data; name=\"userId\"\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[appDelegate.objCurrentUser.userId dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[@"\r\n" dataUsingEncoding:NSUTF8StringEncoding]];     


// message part
[postBody appendData:[[NSString stringWithFormat:@"--%@\r\n", stringBoundary] dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[[NSString stringWithString:@"Content-Disposition: form-data; name=\"firstName\"\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[firstName dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[@"\r\n" dataUsingEncoding:NSUTF8StringEncoding]];

/*** My rest of string parameters are successfully added to request ***/


// media part
[postBody appendData:[[NSString stringWithFormat:@"--%@\r\n", stringBoundary] dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"imageUrl\"; filename=\"dummy.jpg\"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[@"Content-Type: image/jpeg\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[@"Content-Transfer-Encoding: binary\r\n\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
    // get the image data from main bundle directly into NSData object

UIImage *img= leadImage;
NSData *imageData= UIImageJPEGRepresentation(img,90);

[postBody appendData:imageData];

// Image is being uploaded

[postBody appendData:[[NSString stringWithFormat:@"--%@\r\n", stringBoundary] dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"recordSoundUrl\"; filename=\"%@\"\r\n", self.recordingPath] dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[@"Content-Type: application/octet-stream\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[@"Content-Transfer-Encoding: binary\r\n\r\n" dataUsingEncoding:NSUTF8StringEncoding]];


NSData *soundData = [NSData dataWithContentsOfFile:[appDelegate.documentDir stringByAppendingPathComponent:self.recordingPath]];
[postBody appendData:soundData];
[postBody appendData:[@"\r\n" dataUsingEncoding:NSUTF8StringEncoding]];

// final boundary
[postBody appendData:[[NSString stringWithFormat:@"--%@\r\n", stringBoundary] dataUsingEncoding:NSUTF8StringEncoding]];

// add body to post
[postRequest setHTTPBody:postBody];

// Asynch request
NSURLConnection *conn = [NSURLConnection connectionWithRequest:postRequest delegate:self];

If I don't upload the image, then it takes the audio. So I am able to send only one file with the request. Please help me and tell me if I am wrong anywhere.

Thanks in advance.

Answer 1

It is rather simple. Just form multipart body. Suppose you have files to upload and regular params in the 'params' dictionary:

NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString: urlString] cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:54.0];

NSMutableData* body = [NSMutableData data];

NSString* boundary = [NSString randomStringWithLength:64];
[request setValue:[NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundary] forHTTPHeaderField:@"Content-Type"];
NSData *boundaryData = [[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding];

[params enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
   [body appendData:boundaryData];
    // I use special simple class to distinguish file params
   if( [obj isKindOfClass:[FileUpload class]] ) {
        // File upload
        [body appendData: [[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"; filename=\"%@\"\r\n\r\n", key, [obj localName]] dataUsingEncoding:NSUTF8StringEncoding]];
        [body appendData: [obj loadData]]; // It just return NSData with loaded file in it
        [body appendData: [@"\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
    }
    else {
        // Regular param
        [body appendData: [[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"\r\n\r\n%@\r\n", key, obj] dataUsingEncoding:NSUTF8StringEncoding]]
    }
}];
[body appendData:[[NSString stringWithFormat:@"--%@--\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];

[request setValue:[NSString stringWithFormat:@"%d", [body length]] forHTTPHeaderField:@"Content-Length"];
[request setHTTPBody:body];

Now you can just dispatch it in any way:

[NSURLConnection sendAsynchronousRequest:request
                                   queue:queueOfYourChoice
                       completionHandler:^(NSURLResponse *response, NSData *rdata, NSError *error) 

FileUpload class is fairly trivial: it constructs from an url/filename, provides this name as a method and loads the binary content into NSData*. I don't list it for clarity, but if need, I'll add.

Answer 2

Have you looked at using ASIHTTPRequest's ASINetworkQueue to send multiple files.

UPDATE: As per comment below, ASIHTTPRequest is no longer maintained. Use caution with this framework. Other options are MKNetworkKit or AFNetworking.

Answer 3

you may have a problem in setting boundary.

Use this as boundary

NSString boundary = [NSString stringWithString:@"---------------------------14737809831466499882746641449"];

and use this

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

instead of this

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