iOS - DetailViewController not displaying multiple entries/values from JSON - ios

Question

I'm creating a simple iPad app with DetailViewController. Everything works great, but when I try to use multiple level JSON, it doesn't work anymore the app crashes.
I retrieve and loop through data:
-(void) retrieveData{
NSURL * url = [NSURL URLWithString:getDataURL];
NSData * data = [NSData dataWithContentsOfURL:url];
jsonArray = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil];
fruitArray = [[NSMutableArray alloc] init];
//loop through jsonarray
for(int i =0;i < jsonArray.count;i++){
NSString * cName = [[jsonArray objectAtIndex:i] valueForKey:#"cityName"];
NSString * cFruit = [[jsonArray objectAtIndex:i] valueForKey:#"fruit"];
//add object to fruitArray array
[fruitArray addObject:[[Fruits alloc]initWithCityDocumentName:cName andFruit:cFruit]];
}
//reload table view
[self.tableView reloadData];
}
using json:
[{
"id": "1",
"cityName": "London",
"fruit":"Apple"
}, {
"id": "2",
"cityName": "Berlin",
"fruit":"Pear"
}]
and then I set the labels(I hook them up from the storyboard/NIB):
- (void)setLabels{
cityNameLabel.text = currentCity.documentName;
fruitLabel.text = currentCity.documentFruit;
}
All this above work fine.
But as soon as I create multiple values in the JSON for fruits, it does not work!
New JSON:
[{
"id": "1",
"cityName": "London",
"fruit":
["Apple", "Pear", "Orange", "Lemon"]
}, {
"id": "2",
"cityName": "Berlin",
"fruit":
["Mango", "Melon", "Tomatoe", "Avocado"]
}]
It looks to me that I need to somehow programatically create the labels and loop over them? Basically, I need to see multiple values in the Detail View Controller for each id
How can I do it?
I really need a help here :(
Thank you.
EDIT: I was now able to create an Array rather than strings but When I'm creating buttons from them it won't let me add the title based on what's in array:
NSMutableArray * cFruit = [[jsonArray objectAtIndex:i] valueForKey:#"fruit"];
and then:
- (void)setLabels{
for(int i=0;i<=currentCity.documentFruit.count;i++){
UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[button addTarget:self
action:#selector(setLabels)
forControlEvents:UIControlEventTouchUpInside];
//below is my error - looks like it doesn't like setting the titles from array
[button setTitle:[currentCity.documentFruit objectAtIndex:i] forState:UIControlStateNormal];
button.frame = CGRectMake(20.0, ButtonHeightPlusOffsetBetweenButtons * i , 280.0, 40.0);
//Set Tag for future identification
[button setTag:i];
[self.view addSubview:button];
}
}

Answer 1

Here I am providing you complete code, to do so
#import "ViewController.h"
#import "FruitsBO.h"
#interface ViewController ()
#property (strong, nonatomic) IBOutlet UITableView *tblFruit;
#property (nonatomic, strong) NSMutableArray *arrFruitData;
#end
#implementation ViewController
#synthesize arrFruitData;
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
arrFruitData = [[NSMutableArray alloc] init];
[self loadLocalJson];
}
-(void)loadLocalJson
{
NSString *pathStringToLocalFile = [[NSBundle mainBundle] pathForResource:#"Fruit" ofType:#"json"];
NSError *deserializingError;
NSURL *localFileURL = [NSURL fileURLWithPath:pathStringToLocalFile];
NSData *contentOfLocalFile = [NSData dataWithContentsOfURL:localFileURL];
NSArray *objects = [NSJSONSerialization JSONObjectWithData:contentOfLocalFile
options:NSJSONReadingAllowFragments
error:&deserializingError];
[self parseFruit:objects];
}
-(void)parseFruit:(NSArray *)arrFruits
{
for (NSDictionary *dictTemp in arrFruits) {
FruitsBO *fruit = [[FruitsBO alloc] init];
fruit.fruitID = [dictTemp objectForKey:#"id"];
fruit.cityName = [dictTemp objectForKey:#"cityName"];
fruit.arrFruit = [dictTemp objectForKey:#"fruit"];
[arrFruitData addObject:fruit];
fruit = nil;
}
[self.tblFruit reloadData];
}
#pragma mark - TableView Delegate -
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return [self.arrFruitData count];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
FruitsBO *obj = [self.arrFruitData objectAtIndex:section];
return [obj.arrFruit count];
}
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
return 50;
}
- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section
{
return 30;
}
- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
FruitsBO *obj = [self.arrFruitData objectAtIndex:section];
return obj.cityName;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *simpleTableIdentifier = #"fruitIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpleTableIdentifier];
}
FruitsBO *objTemp = [self.arrFruitData objectAtIndex:indexPath.section];
cell.textLabel.text = [objTemp.arrFruit objectAtIndex:indexPath.row];
return cell;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[tableView deselectRowAtIndexPath:indexPath animated:YES];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#end
Here my Json
[{
"id": "1",
"cityName": "London",
"fruit":
["Apple", "Pear", "Orange", "Lemon"]
}, {
"id": "2",
"cityName": "Berlin",
"fruit":
["Mango", "Melon", "Tomatoe", "Avocado"]
},{
"id": "2",
"cityName": "Austin",
"fruit":
["Mango"]
}]
Here my output

Answer 2

The fruitArray array is a local variable in your method. It is never stored anywhere. Whatever you put into it, it will never have any effect.
BTW.
Use a for loop like for (NSDictionary* dict in jsonArray), avoiding the slow indexing operation every time.
You assume that the key fruit contains a string, when it contains an array. That is going to crash your program sooner or later.
Don't use valueForKey, use objectForKey. Eventually you will get very surprising results with valueForKey.

Answer 3

After you updated your JSON, you receive not NSString object, but NSArray for the:
NSString * cFruit = [[jsonArray objectAtIndex:i] valueForKey:#"fruit"];
So you need to do something like this:
NSArray *fruitsArray = [[jsonArray objectAtIndex:i] valueForKey:#"fruit"];
NSString *cFruit = [fruitsArray componentsJoinedByString:#","];