Store JSON output in NSArray - ios

Question

Good morning,
I'm trying to develop my first App and I'm using TableView in order to show my entries from a MySQL database and I'm having some trouble when I have to parse the JSON output.
I have already created the connection with my JSON, but now I need to save all the id in a single Array, all the user in another array, etc, etc. As you can see below in my second code, I need to store them in a NSArray. How can I do that?
That's my JSON
[{"id":"15","user":"1","imagen":"http:\/\/farmaventas.es\/images\/farmaventaslogo.png","date":"2014-09-13"}
,{"id":"16","user":"2","imagen":"http:\/\/revistavpc.es\/images\/vpclogo.png","date":"2014-11-11"}]
And that's my TableViewController.m
- (void)viewDidLoad
{
[super viewDidLoad];
NSString * urlString = [NSString stringWithFormat:#"http://website.com/service.php"];
NSURL * url = [NSURL URLWithString:urlString];
NSData * data = [NSData dataWithContentsOfURL:url];
NSError * error;
NSMutableArray *json = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&error];
// Here I have to store my "user"
self.carMakes = [[NSArray alloc] initWithObjects: nil];
// Here I have to store my "imagen"
self.carModels = [[NSArray alloc] initWithObjects: nil];
}
Thanks in advance.

Answer 1

That's another solution with KVC
NSArray *carMakes = [json valueForKeyPath:#"#unionOfObjects.id"];
NSArray *carModels = [json valueForKeyPath:#"#unionOfObjects.user"];

Answer 2

First of all, you would want to fetch JSON on another thread, so you dont block your main thread with it:
#interface ViewController ()
#end
#implementation ViewController
-(void)viewDidLoad
{
[super viewDidLoad];
[self fetchJson];
}
-(void)fetchJson {
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_async(queue, ^{
NSString * urlString = [NSString stringWithFormat:#"http://website.com/service.php"];
NSURL * url = [NSURL URLWithString:urlString];
NSData * data = [NSData dataWithContentsOfURL:url];
NSError * error;
NSMutableArray *json = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&error];
// I advice that you make your carModels mutable array and initialise it here,before start working with json
self.carModels = [[NSMutableArray alloc] init];
#try {
NSError *error;
NSMutableArray* json = [NSJSONSerialization
JSONObjectWithData:theData
options:NSJSONReadingMutableContainers|NSJSONReadingMutableLeaves
error:&error];
if (error){
NSLog(#"%#",[error localizedDescription]);
}
else{
for(int i=0;i<json.count;i++){
NSDictionary * jsonObject = [json objectAtIndex:i];
NSString* imagen = [jsonObject objectForKey:#"imagen"];
[carModel addObject:imagen];
}
dispatch_async(dispatch_get_main_queue(), ^{
// If you want to do anything after you're done loading json, do it here
}
});
}

Answer 3

NSMutableArray *json = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&error];
// Here you have to store my "user"
self.userArray = [[NSMutableArray alloc]init];
for (NSDictionary *userInfo in json){
//get "user" from json
NSString* user = [userInfo objectForKey:#"user"];
//add to array
[userArray addObject:user];
}
You have use NSMutableArray to add object instead.

Answer 4

Since "json" is array of NSDictionary you can get iterate over it and add to arrays like this:
NSArray *json = #[#{#"id":#"15",#"user":#"1",#"imagen":#"http:\/\/farmaventas.es\/images\/farmaventaslogo.png",#"date":#"2014-09-13"},
#{#"id":#"16",#"user":#"2",#"imagen":#"http:\/\/revistavpc.es\/images\/vpclogo.png",#"date":#"2014-11-11"}];
NSArray *carMakes = [NSArray array];
NSArray *carModels = [NSArray array];
for (NSDictionary *dict in json) {
carMakes = [carMakes arrayByAddingObject:dict[#"id"]];
carModels = [carModels arrayByAddingObject:dict[#"user"]];
}
NSLog(#"%#",carMakes);
NSLog(#"%#",carModels);