Populating UITableView dynamically

Question

I have the following code to fetch the data from URL, store it in arrays, and display it inside the table.

Now the issue is my URL which is feeding data to the tables changes according to the button click i.e. If user clicks button [gainer], data gets fetched from URL related to gainer and so on.

As I have called gainer method in didLoad method, initially data is displayed from the respective URL.But on button click no action is taken. The reason is I'm populating the arrays in methods (gainer and looser) but table is fetching data from the arrays at the time of table creation(and arrays are empty at that point).

I have created button in design view while I'm creating table programmatically.

fetchdataViewController.h

#import <UIKit/UIKit.h>

@interface fetchdataViewController : UIViewController<UITableViewDataSource,UITableViewDelegate>{
    IBOutlet UIWebView *webView;
    NSMutableArray *arr1;
    NSMutableArray *atarr;
    NSMutableArray *arr2;
    NSMutableArray *a;
    NSMutableArray *b;
    NSMutableArray *c;
    NSMutableArray *d;
    UITableView *aTableView;
}
-(IBAction)btnClicked:(id)sender;
-(IBAction)btnClicked1:(id)sender;
-(void)gainer;
-(void)looser;
@property(nonatomic,retain)NSMutableArray *arr1;
@property(nonatomic,retain)NSMutableArray *arr2;
@property(nonatomic,retain)NSMutableArray *atarr;
@property(nonatomic,retain)NSMutableArray *a;
@property(nonatomic,retain)NSMutableArray *b;
@property(nonatomic,retain)NSMutableArray *c;
@property(nonatomic,retain)NSMutableArray *d;
@property(nonatomic,retain)UIWebView *webView;
@property(nonatomic,retain)UITableView *aTableView;
@end

fetchdataViewController.m

#import "fetchdataViewController.h"

@implementation fetchdataViewController

NSMutableArray *atarr;
NSMutableArray *arr1;
NSMutableArray *arr2;
NSMutableArray *a;
NSMutableArray *b;
NSMutableArray *c;
NSMutableArray *d;
NSMutableString *mainstr;
NSMutableString *str;
@synthesize webView;
@synthesize arr1;
@synthesize arr2;
@synthesize atarr;
@synthesize a;
@synthesize b;
@synthesize c;
@synthesize d;
@synthesize aTableView;

int i,j;

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return [a count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView 
         cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *CellIdentifier=@"Cell"; 

    static NSInteger StateTag = 1;
    static NSInteger CapitalTag = 2;
    static NSInteger StateTag1 = 3;
    static NSInteger StateTag2 = 4;


    UITableViewCell *cell=[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if(cell == nil){
        cell=[[[UITableViewCell alloc]initWithFrame:CGRectZero reuseIdentifier:CellIdentifier]autorelease];
        CGRect frame;
        frame.origin.x = 10; 
        frame.origin.y = 5;
        frame.size.height = 35;
        frame.size.width = 170;


        UILabel *capitalLabel = [[UILabel alloc] initWithFrame:frame];
        capitalLabel.tag = CapitalTag;
        [cell.contentView addSubview:capitalLabel];     

        frame.origin.x += 125;
        UILabel *stateLabel = [[UILabel alloc] initWithFrame:frame];
        stateLabel.tag = StateTag;
        [cell.contentView addSubview:stateLabel];

        frame.origin.x += 100;
        UILabel *stateLabel1 = [[UILabel alloc] initWithFrame:frame];
        stateLabel1.tag = StateTag1;
        [cell.contentView addSubview:stateLabel1];


        frame.origin.x += 100;
        UILabel *stateLabel2 = [[UILabel alloc] initWithFrame:frame];
        stateLabel2.tag = StateTag2;
        [cell.contentView addSubview:stateLabel2];


    }
    UILabel *capitalLabel = (UILabel *) [cell.contentView viewWithTag:CapitalTag];
    UILabel *stateLabel = (UILabel *) [cell.contentView viewWithTag:StateTag];
    UILabel *stateLabel1 = (UILabel *) [cell.contentView viewWithTag:StateTag1];
    UILabel *stateLabel2 = (UILabel *) [cell.contentView viewWithTag:StateTag2];

    capitalLabel.text=[a objectAtIndex:indexPath.row];
    stateLabel.text = [b objectAtIndex:indexPath.row];
    stateLabel1.text = [c objectAtIndex:indexPath.row];
    stateLabel2.text = [d objectAtIndex:indexPath.row];


    return cell;
}


-(IBAction)btnClicked:(id)sender{
    [self gainer];
}

-(IBAction)btnClicked1:(id)sender {

    [self looser];
}

-(void)gainer{
    arr1=[[NSMutableArray alloc]init];
    arr2=[[NSMutableArray alloc]init];
    a=[[NSMutableArray alloc]init];
    b=[[NSMutableArray alloc]init];
    c=[[NSMutableArray alloc]init];
    d=[[NSMutableArray alloc]init];

    NSURL *url=[NSURL URLWithString:@"http://ipad.idealake.com/default.aspx?id=G"];
    NSURLRequest *req=[NSURLRequest requestWithURL:url];
    [webView loadRequest:req];

    //storing page data in string
    mainstr=[[NSMutableString alloc] initWithContentsOfURL:url];
    atarr=[mainstr componentsSeparatedByString:@"@"];

    NSString *str2;
    NSString *str3;
    for(int i=0; i<[atarr count]-1; i++)
    {
        // NSLog(@"i=:%i",i); 

        NSMutableString *str = [atarr objectAtIndex:i];
        if (str!= nil)            
            arr1=[str componentsSeparatedByString:@";"];
            for (int k=0;k<[arr1 count];k++)
            {                
                str2 = [arr1 objectAtIndex:k];                
                [arr2 addObject:str2];
                            }


        }
        else
        {
            //NSLog (@"Nill");
        }

    }
    for(int l=0;l<[arr2 count]/4;l++){
        str3=[arr2 objectAtIndex:4*l];
        [a addObject:str3];

        str3=[arr2 objectAtIndex:(4*l)+1];
        [b addObject:str3];

        str3=[arr2 objectAtIndex:(4*l)+2];
        [c addObject:str3];

        str3=[arr2 objectAtIndex:(4*l)+3];
        [d addObject:str3];
    }    
}

-(void)looser{

    arr1=[[NSMutableArray alloc]init];
    arr2=[[NSMutableArray alloc]init];
    a=[[NSMutableArray alloc]init];
    b=[[NSMutableArray alloc]init];
    c=[[NSMutableArray alloc]init];
    d=[[NSMutableArray alloc]init];

    NSURL *url=[NSURL URLWithString:@"http://ipad.idealake.com/default.aspx?id=L"];
    NSURLRequest *req=[NSURLRequest requestWithURL:url];
    [webView loadRequest:req];

    mainstr=[[NSMutableString alloc] initWithContentsOfURL:url];
    atarr=[mainstr componentsSeparatedByString:@"@"];

    NSString *str2;
    NSString *str3;
    for(int i=0; i<[atarr count]-1; i++)
    {

        NSMutableString *str = [atarr objectAtIndex:i];
        if (str!= nil)
        {

            arr1=[str componentsSeparatedByString:@";"];
            for (int k=0;k<[arr1 count];k++)
            {

                str2 = [arr1 objectAtIndex:k];
                [arr2 addObject:str2];
            }          

        }
        else
        {
            //NSLog (@"Nill");
        }

    }
    for(int l=0;l<[arr2 count]/4;l++){
        str3=[arr2 objectAtIndex:4*l];
        [a addObject:str3];

        str3=[arr2 objectAtIndex:(4*l)+1];
        [b addObject:str3];

        str3=[arr2 objectAtIndex:(4*l)+2];
        [c addObject:str3];

        str3=[arr2 objectAtIndex:(4*l)+3];
        [d addObject:str3];
    }
}


- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
}

#pragma mark - View lifecycle

- (void)viewDidLoad
{
    arr1=[[NSMutableArray alloc]init];
    arr2=[[NSMutableArray alloc]init];
    a=[[NSMutableArray alloc]init];
    b=[[NSMutableArray alloc]init];
    c=[[NSMutableArray alloc]init];
    d=[[NSMutableArray alloc]init];

    [self gainer];
    [super viewDidLoad];

    aTableView = [[UITableView alloc] initWithFrame:[[UIScreen mainScreen]applicationFrame] style:UITableViewStyleGrouped];
    aTableView.dataSource = self;
    aTableView.delegate = self;
    aTableView.frame = CGRectMake(0, 10, 720, 500);
    [self.view addSubview:aTableView];

    [super viewDidLoad];
}

- (void)viewDidUnload
{
    [super viewDidUnload];
}

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
}

- (void)viewDidDisappear:(BOOL)animated
{
    [super viewDidDisappear:animated];
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    // Return YES for supported orientations
    return YES;
}

@end

UPDATE

When I run the below code, I get this output. That shaded grey portion is my main concern.

THANKS IN ADVANCE

Answer 1

You need to tell your UITableView that the data has changed by calling reloadData.

Answer 2

Use [self.tableview reloadData] after each change of url and with new arrays filled.