iOS How to retrieve value from JSON after retrieving web response data - ios

Question

I am trying to make a nsurl request and manage to retrieve the web response data out. The problem is i want to retrieve the specific parameter from the JSON list. The parameter i want to retrieve is "id" and display it out in a label.
Here is my viewDIDLoad for establishing the connection:
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
feeds = [[NSMutableArray alloc] init];
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:#"https://coolsoft.mousy.com/v1/messi/reports"]];
// Prepare the variables for the JSON response
// Create a mutable copy of the immutable request and add more headers
NSMutableURLRequest *mutableRequest = [request mutableCopy];
[mutableRequest addValue:#"application/json" forHTTPHeaderField:#"request"];
// Make synchronous request
request = [mutableRequest copy];
// Log the output to make sure our new headers are there
NSLog(#"%#", request.allHTTPHeaderFields);
NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
[connection start];
if(connection)
{
_webResponseData = [NSMutableData data] ;
}
else
{
NSLog(#"Connection is NULL");
}
}
His is my connectionDidFinishLoading method:
-(void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSLog(#"Received %lu Bytes", (unsigned long)[_webResponseData length]);
// NSString *theXML = [[NSString alloc] initWithBytes:
// [_webResponseData mutableBytes] length:[_webResponseData length] encoding:NSUTF8StringEncoding];
// convert to JSON
NSError *myError = nil;
NSDictionary *res = [NSJSONSerialization JSONObjectWithData:self.webResponseData options:NSJSONReadingMutableLeaves error:&myError];
NSString *icon;
// show all values
for(id key in res) {
id value = [res objectForKey:key];
NSString *keyAsString = (NSString *)key;
NSString *valueAsString = (NSString *)value;
NSLog(#"key: %#", keyAsString);
NSLog(#"value: %#", valueAsString);
}
// extract specific value...
NSArray *results = [res objectForKey:#"id"];
for (NSDictionary *result in results) {
icon = [result objectForKey:#"id"];
NSLog(#"icon: %#", icon);
}
output.text = icon;
output = [[UILabel alloc] initWithFrame:CGRectMake(10, 10, 200, 100)]; //adjust label size and position as needed
output.font = [UIFont fontWithName:#"BradleyHandITCTT-Bold" size: 23.0];
output.textColor = [UIColor whiteColor];
output.textAlignment = NSTextAlignmentCenter;
output.numberOfLines = 0; //note: I said number of lines need to be 2
output.backgroundColor = [UIColor clearColor];
output.adjustsFontSizeToFitWidth = YES;
output.tag = 100;
}
Here is output when i NSLOG the res dictionary:
( { date = "2014-08-28T00:00:00Z"; id = 300005; title = "July 2014 USAA Phishing Campaign Uses KeNiHaCk Exploit"; uri = "/v1/joker/reports/300005"; }, { date = "2014-12-16T20:46:29Z"; id = 300062; title = "Two-Year Chinese Spearphishing Campaign Largely Targeted Japanese Aerospace and Energy Industries"; uri = "/v1/joker/reports/300062"; },
Here is my error message:
-[__NSCFArray objectForKey:]: unrecognized selector sent to instance 0x136713360
2015-12-30 11:58:17.692 FYP_IOS_APP[817:323807] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFArray objectForKey:]: unrecognized selector sent to instance 0x136713360'

Answer 1

Your JSON response is {"id":300005,"title":"pink","date":"2014-08-28T00:00:00Z","uri":"www.hipster.com/hip"}}
So, You can use like, lblName.text = [res valueForKey:#"id"];

Answer 2

Your json parsing is OK and it gives you JSON to NSDictionary
but you need some minor changes in pasing that NSDictionary object as below.
see this below code & It may help you
-(void)connectionDidFinishLoading:(NSURLConnection *)connection {
//{"id":300005, "title":"pink", "date":"2014-08-28T00:00:00Z", "uri":"www.hipster.com/hip"}
NSLog(#"Received %lu Bytes", (unsigned long)[_webResponseData length]);
// convert to JSON
NSError *myError = nil;
NSDictionary *res = [NSJSONSerialization JSONObjectWithData:self.webResponseData options:NSJSONReadingMutableLeaves error:&myError];
NSString *icon;
// show all values
for(id key in [res allKeys]) {
NSLog(#"key: %#", key);
NSLog(#"value: %#", [res objectForKey:key]);
}
// extract specific value...
icon = [res valueForKey:#"id"];
NSLog(#"icon: %#", icon);
output.text = icon;
output = [[UILabel alloc] initWithFrame:CGRectMake(10, 10, 200, 100)]; //adjust label size and position as needed
output.font = [UIFont fontWithName:#"BradleyHandITCTT-Bold" size: 23.0];
output.textColor = [UIColor whiteColor];
output.textAlignment = NSTextAlignmentCenter;
output.numberOfLines = 0; //note: I said number of lines need to be 2
output.backgroundColor = [UIColor clearColor];
output.adjustsFontSizeToFitWidth = YES;
output.tag = 100;
}
update
// convert to JSON
NSError *myError = nil;
NSArray *res = [NSJSONSerialization JSONObjectWithData:self.webResponseData options:NSJSONReadingMutableLeaves error:&myError];
// show all values
for(NSDictionary *dic in res) {
for(NSString *key in [dic allKeys]) {
NSLog(#"key: %#", key);
NSLog(#"value: %#", [dic objectForKey:key]);
}
}