[objective-c] Simple http post example in Objective-C?

I have a php webpage that requires a login (userid & password). I have the user enter the information into the app just fine.. but I need an example on how to do a POST request to a website. The apple example on the support site is rather complicated showing a picture upload.. mine should be simpler.. I just want to post 2 lines of text.. Anyone have any good examples?

Alex

 NSMutableDictionary *contentDictionary = [[NSMutableDictionary alloc]init];
[contentDictionary setValue:@"name" forKey:@"email"];
[contentDictionary setValue:@"name" forKey:@"username"];
[contentDictionary setValue:@"name" forKey:@"password"];
[contentDictionary setValue:@"name" forKey:@"firstName"];
[contentDictionary setValue:@"name" forKey:@"lastName"];

NSData *data = [NSJSONSerialization dataWithJSONObject:contentDictionary options:NSJSONWritingPrettyPrinted error:nil];
NSString *jsonStr = [[NSString alloc] initWithData:data
                                          encoding:NSUTF8StringEncoding];
NSLog(@"%@",jsonStr);

NSString *urlString = [NSString stringWithFormat:@"http://testgcride.com:8081/v1/users"];
NSURL *url = [NSURL URLWithString:urlString];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
[request setHTTPMethod:@"POST"];
   [request setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];


[request setHTTPBody:[jsonStr dataUsingEncoding:NSUTF8StringEncoding]];

AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
[manager.requestSerializer setAuthorizationHeaderFieldWithUsername:@"moinsam" password:@"cheese"];
manager.requestSerializer = [AFJSONRequestSerializer serializer];

AFHTTPRequestOperation *operation = [manager HTTPRequestOperationWithRequest:request success:<block> failure:<block>];

You can do using two options:

Using NSURLConnection:

NSURL* URL = [NSURL URLWithString:@"http://www.example.com/path"];
NSMutableURLRequest* request = [NSMutableURLRequest requestWithURL:URL];
request.HTTPMethod = @"POST";
// Form URL-Encoded Body

NSDictionary* bodyParameters = @{
    @"username": @"reallyrambody",
    @"password": @"123456"
};
request.HTTPBody = [NSStringFromQueryParameters(bodyParameters) dataUsingEncoding:NSUTF8StringEncoding];

// Connection

NSURLConnection* connection = [NSURLConnection connectionWithRequest:request delegate:nil];
[connection start];

/*
 * Utils: Add this section before your class implementation
 */

/**
 This creates a new query parameters string from the given NSDictionary. For
 example, if the input is @{@"day":@"Tuesday", @"month":@"January"}, the output
 string will be @"day=Tuesday&month=January".
 @param queryParameters The input dictionary.
 @return The created parameters string.
*/
static NSString* NSStringFromQueryParameters(NSDictionary* queryParameters)
{
    NSMutableArray* parts = [NSMutableArray array];
    [queryParameters enumerateKeysAndObjectsUsingBlock:^(id key, id value, BOOL *stop) {
        NSString *part = [NSString stringWithFormat: @"%@=%@",
            [key stringByAddingPercentEscapesUsingEncoding: NSUTF8StringEncoding],
            [value stringByAddingPercentEscapesUsingEncoding: NSUTF8StringEncoding]
        ];
        [parts addObject:part];
    }];
    return [parts componentsJoinedByString: @"&"];
}

/**
 Creates a new URL by adding the given query parameters.
 @param URL The input URL.
 @param queryParameters The query parameter dictionary to add.
 @return A new NSURL.
*/
static NSURL* NSURLByAppendingQueryParameters(NSURL* URL, NSDictionary* queryParameters)
{
    NSString* URLString = [NSString stringWithFormat:@"%@?%@",
        [URL absoluteString],
        NSStringFromQueryParameters(queryParameters)
    ];
    return [NSURL URLWithString:URLString];
}

Using NSURLSession

- (void)sendRequest:(id)sender
{
    /* Configure session, choose between:
       * defaultSessionConfiguration
       * ephemeralSessionConfiguration
       * backgroundSessionConfigurationWithIdentifier:
     And set session-wide properties, such as: HTTPAdditionalHeaders,
     HTTPCookieAcceptPolicy, requestCachePolicy or timeoutIntervalForRequest.
     */
    NSURLSessionConfiguration* sessionConfig = [NSURLSessionConfiguration defaultSessionConfiguration];

    /* Create session, and optionally set a NSURLSessionDelegate. */
    NSURLSession* session = [NSURLSession sessionWithConfiguration:sessionConfig delegate:nil delegateQueue:nil];

    /* Create the Request:
       Token Duplicate (POST http://www.example.com/path)
     */

    NSURL* URL = [NSURL URLWithString:@"http://www.example.com/path"];
    NSMutableURLRequest* request = [NSMutableURLRequest requestWithURL:URL];
    request.HTTPMethod = @"POST";

    // Form URL-Encoded Body

    NSDictionary* bodyParameters = @{
        @"username": @"reallyram",
        @"password": @"123456"
    };
    request.HTTPBody = [NSStringFromQueryParameters(bodyParameters) dataUsingEncoding:NSUTF8StringEncoding];

    /* Start a new Task */
    NSURLSessionDataTask* task = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
        if (error == nil) {
            // Success
            NSLog(@"URL Session Task Succeeded: HTTP %ld", ((NSHTTPURLResponse*)response).statusCode);
        }
        else {
            // Failure
            NSLog(@"URL Session Task Failed: %@", [error localizedDescription]);
        }
    }];
    [task resume];
}

/*
 * Utils: Add this section before your class implementation
 */

/**
 This creates a new query parameters string from the given NSDictionary. For
 example, if the input is @{@"day":@"Tuesday", @"month":@"January"}, the output
 string will be @"day=Tuesday&month=January".
 @param queryParameters The input dictionary.
 @return The created parameters string.
*/
static NSString* NSStringFromQueryParameters(NSDictionary* queryParameters)
{
    NSMutableArray* parts = [NSMutableArray array];
    [queryParameters enumerateKeysAndObjectsUsingBlock:^(id key, id value, BOOL *stop) {
        NSString *part = [NSString stringWithFormat: @"%@=%@",
            [key stringByAddingPercentEscapesUsingEncoding: NSUTF8StringEncoding],
            [value stringByAddingPercentEscapesUsingEncoding: NSUTF8StringEncoding]
        ];
        [parts addObject:part];
    }];
    return [parts componentsJoinedByString: @"&"];
}

/**
 Creates a new URL by adding the given query parameters.
 @param URL The input URL.
 @param queryParameters The query parameter dictionary to add.
 @return A new NSURL.
*/
static NSURL* NSURLByAppendingQueryParameters(NSURL* URL, NSDictionary* queryParameters)
{
    NSString* URLString = [NSString stringWithFormat:@"%@?%@",
        [URL absoluteString],
        NSStringFromQueryParameters(queryParameters)
    ];
    return [NSURL URLWithString:URLString];
}

Thanks a lot it worked , please note I did a typo in php as it should be mysqli_query( $con2, $sql )

Here i'm adding sample code for http post print response and parsing as JSON if possible, it will handle everything async so your GUI will be refreshing just fine and will not freeze at all - which is important to notice.

//POST DATA
NSString *theBody = [NSString stringWithFormat:@"parameter=%@",YOUR_VAR_HERE];
NSData *bodyData = [theBody dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
//URL CONFIG
NSString *serverURL = @"https://your-website-here.com";
NSString *downloadUrl = [NSString stringWithFormat:@"%@/your-friendly-url-here/json",serverURL];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString: downloadUrl]];
//POST DATA SETUP
[request setHTTPMethod:@"POST"];
[request setHTTPBody:bodyData];
//DEBUG MESSAGE
NSLog(@"Trying to call ws %@",downloadUrl);
//EXEC CALL
[NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue currentQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) {
    if (error) {
        NSLog(@"Download Error:%@",error.description);
    }
    if (data) {

        //
        // THIS CODE IS FOR PRINTING THE RESPONSE
        //
        NSString *returnString = [[NSString alloc] initWithData:data encoding: NSUTF8StringEncoding];
        NSLog(@"Response:%@",returnString);

        //PARSE JSON RESPONSE
        NSDictionary *json_response = [NSJSONSerialization JSONObjectWithData:data
                                                                      options:0
                                                                        error:NULL];

        if ( json_response ) {
            if ( [json_response isKindOfClass:[NSDictionary class]] ) {
                // do dictionary things
                for ( NSString *key in [json_response allKeys] ) {
                    NSLog(@"%@: %@", key, json_response[key]);
                }
            }
            else if ( [json_response isKindOfClass:[NSArray class]] ) {
                NSLog(@"%@",json_response);
            }
        }
        else {
            NSLog(@"Error serializing JSON: %@", error);
            NSLog(@"RAW RESPONSE: %@",data);
            NSString *returnString2 = [[NSString alloc] initWithData:data encoding: NSUTF8StringEncoding];
            NSLog(@"Response:%@",returnString2);
        }
    }
}];

Hope this helps!

From Apple's Official Website :

// In body data for the 'application/x-www-form-urlencoded' content type,
// form fields are separated by an ampersand. Note the absence of a
// leading ampersand.
NSString *bodyData = @"name=Jane+Doe&address=123+Main+St";

NSMutableURLRequest *postRequest = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"https://www.apple.com"]];

// Set the request's content type to application/x-www-form-urlencoded
[postRequest setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];

// Designate the request a POST request and specify its body data
[postRequest setHTTPMethod:@"POST"];
[postRequest setHTTPBody:[NSData dataWithBytes:[bodyData UTF8String] length:strlen([bodyData UTF8String])]];

// Initialize the NSURLConnection and proceed as described in
// Retrieving the Contents of a URL

From : code with chris

    // Create the request.
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://google.com"]];

// Specify that it will be a POST request
request.HTTPMethod = @"POST";

// This is how we set header fields
[request setValue:@"application/xml; charset=utf-8" forHTTPHeaderField:@"Content-Type"];

// Convert your data and set your request's HTTPBody property
NSString *stringData = @"some data";
NSData *requestBodyData = [stringData dataUsingEncoding:NSUTF8StringEncoding];
request.HTTPBody = requestBodyData;

// Create url connection and fire request
NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:request delegate:self];

This is what I recently used, and it worked fine for me:

NSString *post = @"key1=val1&key2=val2";
NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];

NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]];

NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];
[request setURL:[NSURL URLWithString:@"http://www.nowhere.com/sendFormHere.php"]];
[request setHTTPMethod:@"POST"];
[request setValue:postLength forHTTPHeaderField:@"Content-Length"];
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
[request setHTTPBody:postData];

Originally taken from http://deusty.blogspot.com/2006/11/sending-http-get-and-post-from-cocoa.html, but that blog does not seem to exist anymore.

I am a beginner in iPhone apps and I still have an issue although I followed the above advices. It looks like POST variables are not received by my server - not sure if it comes from php or objective-c code ...

the objective-c part (coded following Chris' protocol methodo)

// Create the request.
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://example.php"]];

// Specify that it will be a POST request
request.HTTPMethod = @"POST";

// This is how we set header fields
[request setValue:@"application/xml; charset=utf-8" forHTTPHeaderField:@"Content-Type"];

// Convert your data and set your request's HTTPBody property
NSString *stringData = [NSString stringWithFormat:@"user_name=%@&password=%@", self.userNameField.text , self.passwordTextField.text];
NSData *requestBodyData = [stringData dataUsingEncoding:NSUTF8StringEncoding];
request.HTTPBody = requestBodyData;

// Create url connection and fire request
//NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:request delegate:self];
NSData *response = [NSURLConnection sendSynchronousRequest:request
                                         returningResponse:nil error:nil];

NSLog(@"Response: %@",[[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding]);

Below the php part :

if (isset($_POST['user_name'],$_POST['password'])) 

{

// Create connection
$con2=mysqli_connect($servername, $username, $password, $dbname);
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
else 
{
// retrieve POST vars
$username = $_POST['user_name'];
$password = $_POST['password'];

$sql = "INSERT INTO myTable (user_name, password) VALUES ('$username',   '$password')";
$retval = mysqli_query( $sql, $con2 );
if(! $retval )
{
die('Could not enter data: ' . mysql_error());
}
echo "Entered data successfully\n";

mysqli_close($con2);

}
}
else
{
echo "No data input in php";
}

I have been stuck the last days on this one.

ASIHTTPRequest makes network communication really easy

ASIFormDataRequest *request = [ASIFormDataRequest requestWithURL:url];
[request addPostValue:@"Ben" forKey:@"names"];
[request addPostValue:@"George" forKey:@"names"];
[request addFile:@"/Users/ben/Desktop/ben.jpg" forKey:@"photos"];
[request addData:imageData withFileName:@"george.jpg" andContentType:@"image/jpeg" forKey:@"photos"];