Question

When following the AFNetworking example to upload a form:

NSURL *url = [NSURL URLWithString:@"https://www.example.com/"];
AFHTTPClient *client = [[AFHTTPClient alloc] initWithBaseURL:url];

NSDictionary *params = [NSDictionary dictionaryWithObjectsAndKeys:
                        keyField.text, @"key",
                        valField.text, @"val",
                        nil];

NSData *imageData = UIImagePNGRepresentation(image);

NSURLRequest *request = [client multipartFormRequestWithMethod:@"POST" 
                                                          path:@"/upload" 
                                                    parameters:params 
                                     constructingBodyWithBlock: ^(id <AFMultipartFormData> formData) {
                                         [formData appendPartWithFileData:imageData 
                                                                 mimeType:@"image/png" 
                                                                     name:@"avatar"];
                                     }];

Compilation returns error:

ARC Issue: No known instance method for selector 'appendPartWithFileData:mimeType:name:'

How can I fix it?

Answer 1

It’s a bit strange that the compiler considers this an “ARC issue”. IMHO the AFMultipartFormData protocol doesn’t contain a method called appendPartWithFileData:mimeType:name:. Take a look at the documentation, maybe the protocol was refactored and the method signature change a bit. I’m not sure where does AFMultipartFormData come from, but a short search gave me these docs that suggest you might have success with appendPartWithFileData:name:fileName:mimeType:.