UITableView not properly populating sections with NSArray contents - ios

Question

My Parse cloud code sends back JSON to my iOS app with the following structure:
What I want to do is iterate through this and create a new section in the UITableView for every object in this matchCenterArray.
In this instance, there are three objects in the array, each contains a Top 3 NSDictionary whose value is an array of 3 items, each of which is yet another array of properties. As you can see, I want it set up so that each section has 3 cells, one for each of the top 3 items of that respective matchCenterArray object. I then want it to pull the properties of each item and display it in each cell as the texLabel, detailTextLabel, and thumbnail.
I've tried using a for loop as a solution, but this displays the same item in all cells of the array. This is probably because I'm only looping through matchCenterArray objects, but not additionally looping through items in those objects, as can be seen here:
cell.textLabel.text = [[[[_matchCenterArray objectAtIndex:i] objectForKey:#"Top 3"] objectAtIndex:0]objectForKey:#"Title"];
What I was thinking of doing is nesting a for loop within this one, in place of objectAtIndex:0, but sending a message to a for loop doesn't work.
MatchCenterViewController.m:
#import "MatchCenterViewController.h"
#import <UIKit/UIKit.h>
#interface MatchCenterViewController () <UITableViewDataSource, UITableViewDelegate>
#property (nonatomic, strong) UITableView *matchCenter;
#end
#implementation MatchCenterViewController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
self.matchCenter = [[UITableView alloc] initWithFrame:self.view.bounds style:UITableViewCellStyleSubtitle];
self.matchCenter.frame = CGRectMake(0,50,320,self.view.frame.size.height-100);
_matchCenter.dataSource = self;
_matchCenter.delegate = self;
[self.view addSubview:self.matchCenter];
_matchCenterArray = [[NSArray alloc] init];
}
- (void)viewDidAppear:(BOOL)animated
{
self.matchCenterArray = [[NSArray alloc] init];
[PFCloud callFunctionInBackground:#"MatchCenterTest"
withParameters:#{
#"test": #"Hi",
}
block:^(NSArray *result, NSError *error) {
if (!error) {
_matchCenterArray = result;
[_matchCenter reloadData];
NSLog(#"Result: '%#'", result);
}
}];
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return _matchCenterArray.count;
}
//the part where i setup sections and the deleting of said sections
- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section {
return 21.0f;
}
- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section {
UIView *headerView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 21)];
headerView.backgroundColor = [UIColor lightGrayColor];
// _searchTerm = [[self.matchCenterArray firstObject] objectForKey:#"Search Term"];
UILabel *headerLabel = [[UILabel alloc] initWithFrame:CGRectMake(8, 0, 250, 21)];
// headerLabel.text = [NSString stringWithFormat:#"%#", searchTerm];
// headerLabel.font = [UIFont boldSystemFontOfSize:[UIFont systemFontSize]];
// headerLabel.textColor = [UIColor whiteColor];
headerLabel.backgroundColor = [UIColor lightGrayColor];
[headerView addSubview:headerLabel];
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
button.tag = section + 1000;
button.frame = CGRectMake(300, 2, 17, 17);
[button setImage:[UIImage imageNamed:#"xbutton.png"] forState:UIControlStateNormal];
[button addTarget:self action:#selector(deleteButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
[headerView addSubview:button];
return headerView;
}
- (IBAction)deleteButtonPressed:(UIButton *)sender {
NSLog(#"Search Term: '%#'", _searchTerm);
[PFCloud callFunctionInBackground:#"deleteFromMatchCenter"
withParameters:#{
#"searchTerm": _searchTerm,
}
block:^(NSDictionary *result, NSError *error) {
if (!error) {
NSLog(#"Result: '%#'", result);
}
}];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 3;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
// Initialize cell
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (!cell) {
// if no cell could be dequeued create a new one
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
for (int i = 0; i<[_matchCenterArray count]; i++) {
// populate dictionary with results
//NSDictionary *matchCenterDictionary= [_matchCenterArray objectAtIndex:indexPath.row];
// title of the item
cell.textLabel.text = [[[[_matchCenterArray objectAtIndex:i] objectForKey:#"Top 3"] objectAtIndex:0]objectForKey:#"Title"];
cell.textLabel.font = [UIFont boldSystemFontOfSize:12];
// price of the item
cell.detailTextLabel.text = [NSString stringWithFormat:#"$%#", [[[[_matchCenterArray objectAtIndex:i] objectForKey:#"Top 3"] objectAtIndex:0]objectForKey:#"Price"]];
cell.detailTextLabel.textColor = [UIColor colorWithRed:0/255.0f green:127/255.0f blue:31/255.0f alpha:1.0f];
// image of the item
NSData *imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:[[[[_matchCenterArray objectAtIndex:i] objectForKey:#"Top 3"] objectAtIndex:0] objectForKey:#"Image URL"]]];
[[cell imageView] setImage:[UIImage imageWithData:imageData]];
//imageView.frame = CGRectMake(45.0,10.0,10,10);
}
return cell;
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
/*
#pragma mark - Navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
// Get the new view controller using [segue destinationViewController].
// Pass the selected object to the new view controller.
}
*/
#end

Answer 1

Forget about the loops, the delegate method already run on a loop where the iteration number is equal to the datasource count.
numberOfSectionsInTableView
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return _matchCenterArray.count;
}
numberOfRowsInSection
- (NSInteger)tableView:(UITableView *)tableView
numberOfRowsInSection:(NSInteger)section{
return _matchCenterArray[section][#"Top 3"].count;
}
cellForRowAtIndexPath
- (UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath{
// Initialize cell
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (!cell) {
// if no cell could be dequeued create a new one
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle
reuseIdentifier:CellIdentifier];
}
// title of the item
cell.textLabel.text = _matchCenterArray[indexPath.section][#"Top 3"][indexPath.row][#"Title"];
cell.textLabel.font = [UIFont boldSystemFontOfSize:12];
// price of the item
cell.detailTextLabel.text = [NSString stringWithFormat:#"$%#", _matchCenterArray[indexPath.section][#"Top 3"][indexPath.row][#"Price"];
cell.detailTextLabel.textColor = [UIColor colorWithRed:0/255.0f green:127/255.0f blue:31/255.0f alpha:1.0f];
// image of the item
NSData *imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:_matchCenterArray[indexPath.section][#"Top 3"][indexPath.row][#"Image URL"]]];
[[cell imageView] setImage:[UIImage imageWithData:imageData]];
return cell;
}
Don't harcode your array count, if your json changes, your code will need to change.
In the future you should look into loading the images asynchronously using a library like SDWebImage in order to avoid lags.

Answer 2

cellForRowAtIndexPath: is called once per numberOfRowsInSection:
You need to add numberOfSections as well:
it should look like this:
-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 3;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
// Initialize cell
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (!cell) {
// if no cell could be dequeued create a new one
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
// the following will set the cell attributes for cells in each section
// to customize per section, use indexPath.section to get which section you are at
// title of the item
cell.textLabel.text = [[[[_matchCenterArray objectAtIndex:indexPath.row objectForKey:#"Top 3"] objectAtIndex:0]objectForKey:#"Title"];
cell.textLabel.font = [UIFont boldSystemFontOfSize:12];
// price of the item
cell.detailTextLabel.text = [NSString stringWithFormat:#"$%#", [[[[_matchCenterArray objectAtIndex:indexPath.row] objectForKey:#"Top 3"] objectAtIndex:0]objectForKey:#"Price"]];
cell.detailTextLabel.textColor = [UIColor colorWithRed:0/255.0f green:127/255.0f blue:31/255.0f alpha:1.0f];
// image of the item
NSData *imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:[[[[_matchCenterArray objectAtIndex:indexPath.row] objectForKey:#"Top 3"] objectAtIndex:0] objectForKey:#"Image URL"]]];
[[cell imageView] setImage:[UIImage imageWithData:imageData]];
return cell;
}
Please refer to apple's tableView guide