AFMultipartFormData - Unsupported media type - ios

Question

I am struggling for hours to get AFMultipartFormData to work...
I need to signup a user by sending his info and his picture.
The documentation i have from the back-end developer to achieve this is:
The required parts are: 'registration' with content type 'application/json' and 'pic' with content type image/*
I tried several ways to do this without any success. What is wrong with the code below?
-(void)serverAuthentication {
NSDictionary *jsonDictionary = #{#"clientId":#"someClientId3", #"name":#"Pantelis", #"email":#"someuser#gmail.com", #"password":#"1234567"};
NSData *imageData = UIImageJPEGRepresentation([UIImage imageNamed:#"sampleJohnTsioris"], 0.5);
NSError *error;
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:jsonDictionary options:0 error:&error];
if (!jsonData) {
NSLog(#"JSON ERROR");
} else {
NSString *JSONString = [[NSString alloc] initWithBytes:[jsonData bytes] length:[jsonData length] encoding:NSUTF8StringEncoding];
NSLog(#"JSON OUTPUT: %#",JSONString);
}
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
[manager.requestSerializer setValue:#"application/json" forHTTPHeaderField:#"Content-Type"];
[manager POST:#"http://someserver.com/auth/account/email" parameters:nil constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {
[formData appendPartWithFormData:jsonData name:#"registration"];
[formData appendPartWithFileData:imageData name:#"pic" fileName:#"photo.jpg" mimeType:#"image/*"];
} success:^(AFHTTPRequestOperation *operation, id responseObject) {
NSLog(#"operation=%#",operation);
NSLog(#"Response: %#", responseObject);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"operation=%#",operation);
NSLog(#"Error: %#", error);
}];
}
The error i get:
Error Domain=com.alamofire.error.serialization.response Code=-1011
"Request failed: unsupported media type (415)"

Answer 1

You can't change the content type of the request. It must be "multipart/form-data".
You need to make sure the "registration" part has a mime type of "application/json".
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
[manager POST:#"http://someserver.com/auth/account/email" parameters:nil constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {
[formData appendPartWithFileData:jsonData name:#"registration" fileName:#"user.json" mimeType:#"application/json"];
[formData appendPartWithFileData:imageData name:#"pic" fileName:#"photo.jpg" mimeType:#"image/jpeg"];
} success:^(AFHTTPRequestOperation *operation, id responseObject) {
NSLog(#"operation=%#",operation);
NSLog(#"Response: %#", responseObject);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"operation=%#",operation);
NSLog(#"Error: %#", error);
}];

Answer 2

I found out the solution. As Jeffery Thomas wrote, you can't change the content type of the request, and there was the problem. Specifically, there was no problem at all sending the image but the json object which needed the name "registration" AND the content-type and i couldn't find the proper way to pass both. So, I made up the headers needed to do that (pass the content-type and the name).
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
[manager POST:#"http://vext.dsigned.gr:8080/auth/account/email" parameters:nil constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {
NSMutableDictionary *headers = [NSMutableDictionary dictionaryWithObjectsAndKeys: #"application/json; charset=UTF-8",#"Content-Type", #"form-data; name=\"registration\"",#"Content-Disposition", nil];
[formData appendPartWithHeaders:headers body:jsonData];
[formData appendPartWithFileData:imageData name:#"pic" fileName:#"avatar.png" mimeType:#"image/png"];
} success:^(AFHTTPRequestOperation *operation, id responseObject) {
NSLog(#"operation=%#",operation);
NSLog(#"Response: %#", responseObject);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"operation=%#",operation);
NSLog(#"Error: %#", error);
}];