uploading a image to a webserver using xcode and php

A couple of reactions:

1. If you use AFNetworking, the process of creating these sorts of requests is simpler, getting you out of the weeds of constructing the request yourself:

   AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
   manager.responseSerializer = [AFHTTPResponseSerializer serializer];
   [manager POST:[url absoluteString] parameters:nil constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {
       [formData appendPartWithFileData:imageData name:fieldName fileName:[imagePath lastPathComponent] mimeType:[self mimeTypeForPath:imagePath]];
   } success:^(AFHTTPRequestOperation *operation, id responseObject) {
       NSString *string = [[NSString alloc] initWithData:responseObject encoding:NSUTF8StringEncoding];
       NSLog(@"Success: %@", string);
   } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
       NSLog(@"Error: %@", error);
   }];
   

2. By the way, I usually use MobileCoreServices.framework to get the mime type on the basis of the extension, rather than hard coding it:

   - (NSString *)mimeTypeForPath:(NSString *)path
   {
       // get a mime type for an extension using MobileCoreServices.framework
   
       CFStringRef extension = (__bridge CFStringRef)[path pathExtension];
       CFStringRef UTI = UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, extension, NULL);
       assert(UTI != NULL);
   
       NSString *mimetype = CFBridgingRelease(UTTypeCopyPreferredTagWithClass(UTI, kUTTagClassMIMEType));
       assert(mimetype != NULL);
   
       CFRelease(UTI);
   
       return mimetype;
   }
   

3. I notice that you're retrieving the image into a UIImage, and then using UIImageJPEGRepresentation to get the NSData. Do that if you want or must, but I generally prefer to send the raw data, directly bypassing the roundtrip through a UIImage, which can introduce image degradation and loss of meta data. Instead, you might want to grab the NSData directly:

   NSString *imagePath = [[NSBundle mainBundle] pathForResource:@"mypic" ofType:@"png"]; // note, I'm going back to bundle, not grabbing `UIImage` from imageview
   NSData   *imageData = [NSData dataWithContentsOfFile:imagePath];
   

   If you really must do the roundtrip through UIImage, then you might want to use imageWithContentsOfFile rather than imageNamed, because the latter will cache the image unnecessarily.

4. If you're determined to create the request yourself, this is the routine that I've used in the past:

   - (void)uploadFileAtPath:(NSString *)imagePath
                   forField:(NSString *)fieldName
                        URL:(NSURL*)url
                 parameters:(NSDictionary *)parameters
   {
       NSString *filename = [imagePath lastPathComponent];
       NSData *imageData = [NSData dataWithContentsOfFile:imagePath];
   
       NSMutableData *httpBody = [NSMutableData data];
       NSString *boundary = [self generateBoundaryString];
       NSString *mimetype = [self mimeTypeForPath:imagePath];
   
       // configure the request
   
       NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url];
       [request setCachePolicy:NSURLRequestReloadIgnoringLocalCacheData];
       [request setHTTPShouldHandleCookies:NO];
       [request setTimeoutInterval:30];
       [request setHTTPMethod:@"POST"];
   
       // set content type
   
       NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundary];
       [request setValue:contentType forHTTPHeaderField: @"Content-Type"];
   
       // add params (all params are strings)
   
       [parameters enumerateKeysAndObjectsUsingBlock:^(NSString *parameterKey, NSString *parameterValue, BOOL *stop) {
           [httpBody appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
           [httpBody appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"\r\n\r\n", parameterKey] dataUsingEncoding:NSUTF8StringEncoding]];
           [httpBody appendData:[[NSString stringWithFormat:@"%@\r\n", parameterValue] dataUsingEncoding:NSUTF8StringEncoding]];
       }];
   
       // add image data
   
       if (imageData) {
           [httpBody appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
           [httpBody appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"; filename=\"%@\"\r\n", fieldName, filename] dataUsingEncoding:NSUTF8StringEncoding]];
           [httpBody appendData:[[NSString stringWithFormat:@"Content-Type: %@\r\n\r\n", mimetype] dataUsingEncoding:NSUTF8StringEncoding]];
           [httpBody appendData:imageData];
           [httpBody appendData:[@"\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
       }
   
       [httpBody appendData:[[NSString stringWithFormat:@"--%@--\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
   
       // setting the body of the post to the reqeust
   
       [request setHTTPBody:httpBody];
   
       [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
           if (connectionError)
           {
               NSLog(@"sendAsynchronousRequest error=%@", connectionError);
               return;
           }
   
           NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
           NSLog(@"Success: %@", string);
       }];
   }
   

   Clearly, if you're not using any parameters (which you don't appear to be doing), you can just pass nil for that parameter. But the key is that it supports additional parameters if you need it. I also employ asynchronous network requests, because one should never issue synchronous network requests on the main queue.

   This uses the generateBoundaryString method from Apple's SimpleURLConnections example:

   - (NSString *)generateBoundaryString
   {
       // generate boundary string
       //
       // adapted from http://developer.apple.com/library/ios/#samplecode/SimpleURLConnections
       //
       // Note in iOS 6 and later, you can just:
       //
       //    return [NSString stringWithFormat:@"Boundary-%@", [[NSUUID UUID] UUIDString]];
   
       CFUUIDRef  uuid;
       NSString  *uuidStr;
   
       uuid = CFUUIDCreate(NULL);
       assert(uuid != NULL);
   
       uuidStr = CFBridgingRelease(CFUUIDCreateString(NULL, uuid));
       assert(uuidStr != NULL);
   
       CFRelease(uuid);
   
       return [NSString stringWithFormat:@"Boundary-%@", uuidStr];
   }
   

5. If you prefer, I retrofitted your code, modeled on some of the above code:

   NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url];
   [request setHTTPMethod:@"POST"];
   
   NSString *boundary = @"---------------------------14737809831466499882746641449";
   NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundary];
   [request addValue:contentType forHTTPHeaderField: @"Content-Type"];
   
   NSMutableData *body = [NSMutableData data];
   [body appendData:[[NSString stringWithFormat:@"--%@\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
   [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"; filename=\"%@\"\r\n", fieldName, [imagePath lastPathComponent]] dataUsingEncoding:NSUTF8StringEncoding]];
   [body appendData:[[NSString stringWithFormat:@"Content-Type: %@\r\n\r\n", [self mimeTypeForPath:imagePath]] dataUsingEncoding:NSUTF8StringEncoding]];
   [body appendData:[NSData dataWithData: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];
   
   NSLog(@"%@",returnString);
   

6. Personally, I'd suggest changing your PHP code to generate a JSON response (as that will be easier for your app to consume).

By the way, I've tested the above with my PHP code. If you're still having problems, I'd suggest sharing your PHP code with us as well, as the construction of a well-formed request is intimately tied to what the PHP code requires.