Call function on Server from iOS app - Objective C

Question

If you are familiar with Parse.com's Javascript SDK, this is what I am trying to do for my own server for my iOS app (Objective-c). I want to be able to send some a string to the function that is on my server, have the server run its function and then return a string to the app or some xml or JSON data.

Is this even possible?

I am new to doing something like this having an app make a call to a server. I have looked into opening a port on my server, but have been unable to find a way to receive data back to the iOS app. (I found this lib but its for OS X https://github.com/armadsen/ORSSerialPort). Also Im not sure if I have a function run with an open port on the server. So how can I set it up so I can make a call to my server and run a function?

Any help would be much appreciated.

Answer 1

You just need to POST data to your server.

Port could be anything you want.

Host your script with a domain url so that you can make network request publicly.

You can try this function:

-(NSData *)post:(NSString *)postString url:(NSString*)urlString{

    //Response data object
    NSData *returnData = [[NSData alloc]init];

    //Build the Request
    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:urlString]];
    [request setHTTPMethod:@"POST"];
    [request setValue:[NSString stringWithFormat:@"%lu", (unsigned long)[postString length]] forHTTPHeaderField:@"Content-length"];
    [request setHTTPBody:[postString dataUsingEncoding:NSUTF8StringEncoding]];

    //Send the Request
    returnData = [NSURLConnection sendSynchronousRequest: request returningResponse: nil error: nil];

    //Get the Result of Request
    NSString *response = [[NSString alloc] initWithBytes:[returnData bytes] length:[returnData length] encoding:NSUTF8StringEncoding];

    bool debug = YES;

    if (debug && response) {
        NSLog(@"Response >>>> %@",response);
    }


    return returnData;
}

And here is how you use it:

NSString *postString = [NSString stringWithFormat:@"param=%@",param];
NSString *urlString = @"https://www.yourapi.com/yourscript.py";

NSData *returnData =  [self post:postString url:urlString];

PHP

<?php
$response=array();
if(isset($_POST['param'])){
  $response['success'] = true;
  $response['message'] = 'received param = '.$_POST['param'];
}else{
  $response['success'] = false;
  $response['message'] = 'did not receive param';
}
$json = json_encode($response);
echo $json;