AFNetworking POST to REST webservice - iphone

Question

Brief backstory, our previous developer used ASIHTTPRequest to make POST requests and retrieve data from our webservice. For reasons unknown this portion of our app stopped working. Seemed like good enough time to future proof and go with AFNetworking. REST webservice runs on the CakePHP framework.
In short I am not receiving the request response string using AFNetworking.
I know the webservice works because I am able to successfully post data and receive the proper response using curl:
curl -d "data[Model][field0]=field0value&data[Model][field1]=field1value" https://example.com/api/class/function.plist
Per the previous developer's instructions I came up with the following.
#import "AFHTTPRequestOperation.h"
…
- (IBAction)loginButtonPressed {
NSURL *url = [NSURL URLWithString:#"https://example.com/api/class/function.plist"];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
[request setHTTPMethod:#"POST"];
[request setValue:#"application/x-www-form-urlencoded" forHTTPHeaderField:#"Content-Type"];
[request setValue:[usernameTextField text] forHTTPHeaderField:#"data[User][email]"];
[request setValue:[passwordTextField text] forHTTPHeaderField:#"data[User][password]"];
AFHTTPRequestOperation *operation = [[[AFHTTPRequestOperation alloc] initWithRequest:request] autorelease];
[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
NSLog(#"operation hasAcceptableStatusCode: %d", [operation.response statusCode]);
NSLog(#"response string: %# ", operation.responseString);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"error: %#", operation.responseString);
}];
[operation start];
}
output:
operation hasAcceptableStatusCode: 200
response string: a blank plist file
attempted solution 1:
AFNetworking Post Request
the proposed solution uses a function of AFHTTPRequestOperation called operationWithRequest. However, when I attempt to use said solution I get a warning "Class method '+operationWithRequest:completion:' not found (return type defaults to 'id'"
attempted solution 2: NSURLConnection. output: I'm able to print the success log messaged but not the response string.
*update - returns blank plist.
NSMutableURLRequest *req = [NSMutableURLRequest requestWithURL:url];
NSString *httpBodyData = #"data[User][email]=username#example.com&data[User][password]=awesomepassword";
[httpBodyData dataUsingEncoding:NSUTF8StringEncoding];
[req setHTTPMethod:#"POST"];
[req setHTTPBody:[NSData dataWithContentsOfFile:httpBodyData]];
NSHTTPURLResponse __autoreleasing *response;
NSError __autoreleasing *error;
[NSURLConnection sendSynchronousRequest:req returningResponse:&response error:&error];
// *update - returns blank plist
NSData *responseData = [NSURLConnection sendSynchronousRequest:req returningResponse:nil error:nil];
NSString *str = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
NSLog(#"responseData %#",str);
if (error == nil && response.statusCode == 200) {
// Process response
NSLog(#"success");//returns success code of 200 but blank
NSLog(#"resp %#", response );
} else {
// Process error
NSLog(#"error");
}

Answer 1

These are the essential (stripping out conditions I've made for my own use) lines that ended up satisfying my request to the web service. Thanks for the suggestions #8vius and #mattt !
- (IBAction)loginButtonPressed {
NSURL *baseURL = [NSURL URLWithString:#"https://www.example.com/api/class"];
//build normal NSMutableURLRequest objects
//make sure to setHTTPMethod to "POST".
//from https://github.com/AFNetworking/AFNetworking
AFHTTPClient *httpClient = [[AFHTTPClient alloc] initWithBaseURL:baseURL];
[httpClient defaultValueForHeader:#"Accept"];
NSDictionary *params = [NSDictionary dictionaryWithObjectsAndKeys:
[usernameTextField text], kUsernameField,
[passwordTextField text], kPasswordField,
nil];
NSMutableURLRequest *request = [httpClient requestWithMethod:#"POST"
path:#"https://www.example.com/api/class/function" parameters:params];
//Add your request object to an AFHTTPRequestOperation
AFHTTPRequestOperation *operation = [[[AFHTTPRequestOperation alloc]
initWithRequest:request] autorelease];
//"Why don't I get JSON / XML / Property List in my HTTP client callbacks?"
//see: https://github.com/AFNetworking/AFNetworking/wiki/AFNetworking-FAQ
//mattt's suggestion http://stackoverflow.com/a/9931815/1004227 -
//-still didn't prevent me from receiving plist data
//[httpClient registerHTTPOperationClass:
// [AFPropertyListParameterEncoding class]];
[httpClient registerHTTPOperationClass:[AFHTTPRequestOperation class]];
[operation setCompletionBlockWithSuccess:
^(AFHTTPRequestOperation *operation,
id responseObject) {
NSString *response = [operation responseString];
NSLog(#"response: [%#]",response);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"error: %#", [operation error]);
}];
//call start on your request operation
[operation start];
[httpClient release];
}

Answer 2

Use AFHTTPClient -postPath:parameters:success:failure:, passing your parameters (nested dictionaries/arrays are fine). If you're expecting a plist back, be sure to have the client register AFPropertyListRequestOperation.
In any case, setValue:forHTTPHeaderField: is not what you want here. HTTP headers are for specifying information about the request itself; data is part of the request body. AFHTTPClient automatically converts parameters into either a query string for GET requests or an HTTP body for POST, et al.