How to print the web service request and response from dataTaskWithRequest

Question

Can anyone guide me how to print the web service request and response from dataTaskWithRequest in json format while using swift 4.0 and objective C.

Links tried:

How to print NSMutableURLRequest?

I can print them, but its not printing in proper format. I need in a format so that I can paste it in postman or web browser and test.

Request Format which I need:

eg:https://restcountries.eu/rest/v2/name/aruba?fullText=true

For Response:

Need the response format like the above url's response which I can view them in http://jsonviewer.stack.hu.

Answer 1

To get response objects in string and dictionary objects :

NSURLSessionDataTask *task = [session dataTaskWithRequest:URLRequest
                                                completionHandler:
                                      ^(NSData *data, NSURLResponse *response, NSError *error) 
{ 
    // your code 

    NSString *responseString = [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding];

    id responseObjects = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments error:&error];
}

To get pretty printed json format from NSData object or dictionary :

NSData *jsonData = [NSJSONSerialization dataWithJSONObject:yourDictionary
                                                   options:NSJSONWritingPrettyPrinted
                                                     error:&error];

NSString *strData = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
NSLog(@"Params : %@", strData);

EDIT

To print json Request, try using this :

// for POST/JSON type

NSLog(@"Request body %@", [[NSString alloc] initWithData:[request HTTPBody] encoding:NSUTF8StringEncoding]);

// for GET type

NSLog(@"Request url : %@", [[request.URL absoluteString] stringByRemovingPercentEncoding]);

Answer 2

Swift 4

Use this function to print your request. Just pass your request to this function and remember that your request should be Dictionary.

   func prettyPrintRequest(with json: [String : Any]) -> String{
    let data = try! JSONSerialization.data(withJSONObject: json, options: .prettyPrinted)
    let string = String(data: data, encoding: String.Encoding(rawValue: String.Encoding.utf8.rawValue))
    if let string  = string{

        return string
    }
    print("something went wrong")
    return ""
}

UPDATED to objective c code

-(void)prettyPrintRequest:(NSDictionary*)request{
NSError *error;
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:request
                                                   options:NSJSONWritingPrettyPrinted
                                                     error:&error];

if (jsonData) {
     NSString *jsonString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
    NSLog(@"Valid Json String is %@", jsonString);

} else {
    NSLog(@"Error is : %@", error);

}
}

Answer 3

For Printing the response in JSON format, so that you can copy/paste it into Postman and check.

In Objective C:

NSString* jsonString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
NSLog(@"jsonString: %@", jsonString);

In Swift 4:

let dataString = String(data: data, encoding: String.Encoding(rawValue: String.Encoding.utf8.rawValue))!
print(dataString)

Answer 4

You can print JSON data like,

if error == nil {
    do {
        let json = try JSONSerialization.jsonObject(with: data!, options: .allowFragments)
        print(json)
        let dic = json as! NSDictionary
        print(dic)
    }
    catch {
        print("Throw error when convert to json")
    }
}