Uploading an image from iOS 5

Lately I’ve been working steadily towards getting an iOS app released for my company, KaiNexus.  The first pass at this app will have the basic ability to submit an idea from your phone and be able to attach a picture.  Since I am still a novice with Objective-C it was no surprise when I ran into a brick wall when trying to upload the image from the app.  This prompted me to ask on stackoverflow to see what I had done wrong.

As it turns out, I was using an incorrect combination of line endings and content types.  I now have working code in my app and figured I would share it so that anyone else running into this problem would have a starting point.  Below is the function I wrote to handle uploading an image in Objective-C on iOS 5 (the grails pieces can be found on the SO question).

+ (BOOL)uploadImage:(UIImage *)image withName:(NSString *)fileName toURL:(NSURL *)url {
    NSData *imageData = UIImageJPEGRepresentation(image, 100);
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    [request setHTTPMethod:@"POST"];

    NSString *boundary = @"0x0hHai1CanHazB0undar135";
    NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundary];
    [request setValue:contentType forHTTPHeaderField:@"Content-Type"];

    NSMutableData *body = [NSMutableData data];
    [body appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",boundary] dataUsingEncoding: NSUTF8StringEncoding]];
    [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"imageToAttach\"; filename=\"%@\"\r\n",fileName]dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[[NSString stringWithFormat:@"Content-Type: image/jpeg\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:imageData];
    [body appendData:[[NSString stringWithFormat:@"\r\n--%@--\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
    [request setHTTPBody:body];

    NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
    NSString *returnString = [[NSString alloc] initWithData:returnData encoding:NSUTF8StringEncoding];


    return YES;

Steve Good

Professional software engineer, amatuer photographer, and part-time mountain biker.