tableview endless scroll index page jump ios - ios

Question

I updated the code
hi I'm using a tableview populated from a web service in my iOS app
implementing the endless scroll the page number jumps by 4 every time and is not incremented every page has 10 items that are put in an array from the tableview to display.
my code
#interface TableViewController ()
#end
#implementation TableViewController
#synthesize articlesArray;
#synthesize currentpage;
#synthesize articles;
#synthesize page;
#synthesize rowww;
- (void)viewDidLoad {
[super viewDidLoad];
self.articlesArray = [[NSMutableArray alloc] init];
self.articles = [[NSMutableArray alloc]init];
currentpage = 1;
page = 2;
[self fetchData:(int)currentpage];
[self.tableView registerNib:[UINib nibWithNibName:#"ArticleCell" bundle:nil] forCellReuseIdentifier:#"ArticleCell"];
}
-(void)makeRequest:(int)page1{
if ([DGUtilFunctions isInternetAvailable])
{
NSString *urlString = [NSString
stringWithFormat:#"http://url/wp-json/wp/v2/posts?page=%d",(int) page1];
NSURLRequest *request = [[NSURLRequest alloc] initWithURL:[NSURL URLWithString:urlString]];
NSData *theData = [NSURLConnection sendSynchronousRequest:request
returningResponse:nil
error:nil];
self.articles = [NSJSONSerialization JSONObjectWithData:theData
options:NSJSONReadingMutableContainers
error:nil];
NSLog(#"self.articles %#",self.articles);
}
else
{
UIAlertController* _alertView = [ UIAlertController alertControllerWithTitle:nil
message:#"Veuillez vous connecter à internet. " preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction* defaultAction = [UIAlertAction actionWithTitle:#"OK" style:UIAlertActionStyleDefault
handler:^(UIAlertAction * action){} ];
[_alertView addAction:defaultAction ];
[self presentViewController:_alertView animated:YES completion:nil];
}
}
-(void) fetchData:(int)page2 {
if ([DGUtilFunctions isInternetAvailable])
{
NSString *urlString = [NSString
stringWithFormat:#"http://url/wp-json/wp/v2/posts?&page=%d", (int)page2];
NSURLRequest *request = [[NSURLRequest alloc] initWithURL:[NSURL URLWithString:urlString]];
NSData *theData = [NSURLConnection sendSynchronousRequest:request
returningResponse:nil
error:nil];
self.articlesArray = [NSJSONSerialization JSONObjectWithData:theData
options:NSJSONReadingMutableContainers
error:nil];
NSLog(#"articlesarray %#",self.articlesArray);
}
else
{
UIAlertController* _alertView = [ UIAlertController alertControllerWithTitle:nil
message:#"Veuillez vous connecter à internet. " preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction* defaultAction = [UIAlertAction actionWithTitle:#"OK" style:UIAlertActionStyleDefault
handler:^(UIAlertAction * action){} ];
[_alertView addAction:defaultAction ];
[self presentViewController:_alertView animated:YES completion:nil];
}
}
- (void)scrollViewDidScroll:(UIScrollView *)aScrollView {
CGPoint offset = aScrollView.contentOffset;
CGRect bounds = aScrollView.bounds;
CGSize size = aScrollView.contentSize;
UIEdgeInsets inset = aScrollView.contentInset;
float y = offset.y + bounds.size.height - inset.bottom;
float h = size.height;
float reload_distance = 40;
if(y > h + reload_distance) {
NSLog(#"load more rows");
[self makeRequest:(int)page];
page++;
NSLog(#"currentpage %d",(int)page);
[self.articlesArray addObjectsFromArray:self.articles];
[self.tableView reloadData];
}
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 2;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
if (section==0)
{
return 0;
}
else{
return [self.articlesArray count] + [self.articlesArray count] / 4;
}
}
- (NSIndexPath *)tableView:(UITableView *)tableView willSelectRowAtIndexPath:(NSIndexPath *)indexPath {
if(self.sidebarMenuOpen == YES){
return nil;
} else {
return indexPath;
}
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
NSInteger row = [indexPath row];
if (3 == (row % 4)) { // or 0 == if you want the first cell to be an ad!
static NSString *MyIdentifier = #"AdCell";
AdViewCell *cell = (AdViewCell *)[tableView dequeueReusableCellWithIdentifier:MyIdentifier];
if ((cell == nil) || (![cell isKindOfClass: AdViewCell.class]))
{
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:#"AdCell" owner:self options:nil];
cell = [nib objectAtIndex:0];
cell = [[AdViewCell alloc] initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:MyIdentifier] ;
}
GADBannerView *bannerView = [[GADBannerView alloc] initWithAdSize:kGADAdSizeMediumRectangle];
double width = (cell.contentView.frame.size.width/2)-(bannerView.frame.size.width/2);
double heigth = (cell.contentView.frame.size.height/2)-(bannerView.frame.size.height/2);
bannerView =[[GADBannerView alloc] initWithFrame:CGRectMake(width,heigth,300,250)];
bannerView.autoresizingMask = (UIViewAutoresizingFlexibleLeftMargin |
UIViewAutoresizingFlexibleRightMargin |
UIViewAutoresizingFlexibleTopMargin |
UIViewAutoresizingFlexibleBottomMargin);
bannerView.adUnitID = #""; //admob
bannerView.rootViewController =self;
GADRequest *request = [GADRequest request];
[bannerView loadRequest:request];
[cell.contentView addSubview:bannerView];
return cell;
}
else {
static NSString *simpleTableIdentifier = #"ArticleCell";
ArticleViewCell *cell = (ArticleViewCell *)[tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier ];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
if ((cell == nil) || (![cell isKindOfClass: ArticleViewCell.class]))
{
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:#"ArticleCell" owner:self options:nil];
cell = [nib objectAtIndex:1];
cell = [[ArticleViewCell alloc] initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:simpleTableIdentifier] ;
}
NSInteger offset = indexPath.row / 4;
NSInteger roww = indexPath.row - offset;
rowww = roww;
NSDictionary * tempDictionary = [self.articlesArray objectAtIndex:roww];
NSString *imageUrl = [[self.articlesArray objectAtIndex:roww]objectForKey:#"featured_image"];
imageUrl = [imageUrl stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^{
[cell.thumbnailImageView sd_setImageWithURL:[NSURL URLWithString:imageUrl ] placeholderImage:nil options:SDWebImageRetryFailed completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, NSURL *imageURL) {
if (image){
// Set your image over here
}else{
//something went wrong
NSLog(#"Error occured : %#", [error description]);
}
}];
});
NSString * title=[tempDictionary valueForKeyPath:#"title"];
cell.titleLabel.text = title;
return cell;
}
}
- (void) tableView: (UITableView *) tableView didSelectRowAtIndexPath: (NSIndexPath *) indexPath {
[self performSegueWithIdentifier:#"showarticle" sender:self];
}
// Override to support rearranging the table view.
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath {
}
// Override to support conditional rearranging of the table view.
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath {
// Return NO if you do not want the item to be re-orderable.
return NO;
}
#end
thanks

Answer 1

Imagine a UITableView with 10 UITableViewCells.
Once the UITableView loads, it will call tableView:willDisplayCell:forRowAtIndexPath for each cell. Your implementation increments the page number each time this method is called which causes the page number to jump from 1 to page 10. You should get rid of this method.
Instead, you should rely only on the - (void)scrollViewDidScroll:(UIScrollView *)scrollView callback. Try this:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView_
{
CGFloat actualPosition = scrollView_.contentOffset.y;
CGFloat contentHeight = scrollView_.contentSize.height - (self.tableview.frame.size.height);
if (actualPosition >= contentHeight) {
[self makeRequet:++currentPage];
[self.articlesArray addObjectsFromArray:self.articlesArray];
[self.tableView reloadData];
}

Answer 2

You just need to use this
[tableView insertRowsAtIndexPaths:#[indexPathArray]]
in your request completion handler block
and don't forget to increase your count of rows in
(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section