How to calculate dynamic no of rows in each section - ios

Question

I am developing iPhone app and i got stuck at one point need your help,
I have tableview with dynamic sections and dynamic no of rows in each section.
Here is my json data format: http://pastebin.com/jmsq1pxu
I have fetched all this data in my array,
now i have calculated number of sections in tableview based on SpecGroupLabel key:
I found section count as 10
General,
Body,
Display,
Memory,
Camera,
Connectivity,
OS,
Processor,
Battery,
Sound
Now in each section i want to calculate no of rows.
Here in this case 1st section is General 2nd is Body 3rd is Display and so on upto 10th section Sound i want to calculate no of rows in each section ?
and finally how should i display different section and it's row in cellForRowAtIndexPath ?
Please help and thanks in advance.

Answer 1

I'll explain in detail
Suppose you have the following json
{
data:[
{
label:Fruit,
name: Orange,
},
{
label:Month,
name: June,
},
{
label:Color,
name: Blue,
},
{
label:Color,
name: Red,
},
{
label:Fruit,
name: Apple,
},
{
label:Color,
name: Pink,
},
{
label:Fruit,
name: Mango,
},
{
label:Month,
name: May,
},
{
label:Color,
name: White,
},
]
}
And you want your table to look like
Fruit
Orange
Apple
Mango
Month
June
May
Color
Blue
Red
Pink
White
NSMutableDictionary *dict;
- (void)viewDidLoad
{
[super viewDidLoad];
dict = [[NSMutableDictionary alloc] init];
NSArray *jsonArray ;// this is your data json array
for (int i = 0; i < jsonArray.count; i++) {
NSDictionary *dataDict = [jsonArray objectAtIndex:i];
NSString *getLabel = [dataDict objectForKey:#"label"];
if([dict objectForKey:getLabel] == NULL){
//this label is not present in your dict, so that means its a new section.
NSMutableArray *newArray = [[NSMutableArray alloc] init];
[newArray addObject:[dataDict objectForKey:#"name"]];
[dict setObject:newArray forKey:getLabel];
}else{
// already added to the dictionary
NSMutableArray *getArray = [dict objectForKey:getLabel];
[getArray addObject:[dataDict objectForKey:#"name"]];
}
}
// Do any additional setup after loading the view, typically from a nib.
}
-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{
return dict.count;
}
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
NSArray *getArray = [dict.allValues objectAtIndex:section];
return getArray.count;
}
-(CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection: (NSInteger)section{
return 40.0;
}
-(UIView*) tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section{
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0.0, 0.0, 320.0, 40.0)];
UILabel *sectionLabel = [[UILabel alloc] initWithFrame:CGRectMake(0.0, 0.0, 320.0, 40.0)];
sectionLabel.text = [dict.allKeys objectAtIndex:section];
[view addSubview:sectionLabel];
return view;
}
-(UITableViewCell*) tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"cell" forIndexPath:indexPath];
NSArray *getArray = [dict.allValues objectAtIndex:indexPath.section];
cell.textLabel.text = [getArray objectAtIndex:indexPath.row];
}

Answer 2

the number of the groups:
NSInteger _numberOfGroups = [[_array valueForKeyPath:#"#distinctUnionOfObjects.SpecGroupLabel"] count];
the number of the items in a particular group (e.g. "General"):
NSInteger _numberOfItemsInAGroup = [[_array filteredArrayUsingPredicate:[NSPredicate predicateWithBlock:^BOOL(NSDictionary * evaluatedObject, NSDictionary *bindings) {
return [[evaluatedObject valueForKey:#"SpecGroupLabel"] isEqualToString:#"General"]; // or Body, Display, Memory, Camera, Connectivity, etc...
}]] count];
NOTE: you can read more about KVC here and predicates here.

Answer 3

You need to create an array of arrays. Each array will represent a section. Within each array add your data for an individual row.
To get number of rows in a section:
NSInteger rows = array[section].count
In cellForRowAtIndexPath use the indexpath
CustomObject *object = [array[indexPath.section] objectAtIndex:indexPath.row]