objective c - NSURLConnection to upload file asynchonrously?

Question

I'm kinda of new at ios development, I've been reading and searching but cannot find a working example or an example of how to upload a file from iphone to webserver asychronously..

I'm able to upload synchronously using

[NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];

it works, but it blocks my main thread.

NSUrlConnection has this delegate (connection:didSendBodyData:totalBytesWritten:totalBytesExpectedToWrite:)

but I've no idea how to implement it.

Can someone please point me in the right direction?

Answer 1

I have managed to get uploading to work with NSURLConnection asynchronously with this:

-(NSURLRequest *)postRequestWithURL: (NSString *)url

                                data: (NSData *)data   
                            fileName: (NSString*)fileName
{

// from http://www.cocoadev.com/index.pl?HTTPFileUpload

    //NSMutableURLRequest *urlRequest = [NSMutableURLRequest requestWithURL:url];

    NSMutableURLRequest *urlRequest = [[[NSMutableURLRequest alloc] init] autorelease];
    [urlRequest setURL:[NSURL URLWithString:url]];
    //[urlRequest setURL:url];

    [urlRequest setHTTPMethod:@"POST"];

    NSString *myboundary = [NSString stringWithString:@"---------------------------14737809831466499882746641449"];
    NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@",myboundary];
    [urlRequest addValue:contentType forHTTPHeaderField: @"Content-Type"];


    //[urlRequest addValue: [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundry] forHTTPHeaderField:@"Content-Type"];

    NSMutableData *postData = [NSMutableData data]; //[NSMutableData dataWithCapacity:[data length] + 512];
    [postData appendData:[[NSString stringWithFormat:@"
--%@
", myboundary] dataUsingEncoding:NSUTF8StringEncoding]];
    [postData appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name="userfile"; filename="%@"
", fileName]dataUsingEncoding:NSUTF8StringEncoding]];
    [postData appendData:[[NSString stringWithString:@"Content-Type: application/octet-stream

"] dataUsingEncoding:NSUTF8StringEncoding]];
    [postData appendData:[NSData dataWithData:data]];
    [postData appendData:[[NSString stringWithFormat:@"
--%@--
", myboundary] dataUsingEncoding:NSUTF8StringEncoding]];

    [urlRequest setHTTPBody:postData];
    return urlRequest;
}

usage is as follows:

    NSURLRequest *urlRequest = [self postRequestWithURL:urlString
                                                   data:aVideo.msgvid
                                               fileName:filename];

    uploadConnection =[[NSURLConnection alloc] initWithRequest:urlRequest delegate:self];