AFNetworking POST to REST webservice

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");
}

Hello, Pouria, did you try using NSURLConnection to send a synchronous request? — 8vius, Mar 29 '12 at 15:17
Do you have everything on the server side set up properly? Like extension parsing, the layouts for the response and the views for them? It seems more of a server problem than a client one. — 8vius, Mar 29 '12 at 19:08
I ended up resolving this. I'm at work right now and will post updates later. — Pouria Almassi, Mar 30 '12 at 18:29

score 18 · Accepted Answer · edited Feb 05 '13 at 13:06

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];
}

Registering for plist operations only affects request operations created using `AFHTTPClient -HTTPRequestOperationWithRequest:success:failure:`. `alloc init`-ing `AFHTTPRequestOperation` is always going to give you an `AFHTTPRequestOperation`. — mattt, Apr 05 '12 at 05:00
@pouria, What is Path here. Is it like a same URL. Please help me i got stuck at Path. — Ganesh G, Jul 05 '13 at 10:55
@G.Ganesh I'm getting to this a bit late. The Path was simply a method of the class that responded to HTTP POSTs with a given set of params. I hope you resolved your issue. — Pouria Almassi, Oct 03 '13 at 07:26

score 7 · Answer 2 · answered Mar 29 '12 at 19:07

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.

I resolved this issue but I have a feeling I am still doing something wrong or inefficiently. I'd greatly appreciate it if you had a quick look at my solution. Thanks! — Pouria Almassi, Apr 03 '12 at 21:11

AFNetworking POST to REST webservice

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