Why is my UITabeViewContent reorders everytime I refresh it? - ios

Question

i have a UITebleView with costume UITableViewCells. Every time I refresh the them the content is reordering itself. anyone know why?
I am fatching the data from a JSON, I dont do some sort of sorting, I just display the data acording to the TableViewCell indexpath.row
And this is the code I set the UITableViewCell content:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *costumeCell = #"Cell";
StoreCell *cell = [tableView dequeueReusableCellWithIdentifier:costumeCell];
if (!cell) {
cell = [[StoreCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:costumeCell];
}
NSDictionary *dict;
dict = [application objectAtIndex:indexPath.row];
[downloadQueue addOperationWithBlock:^{
name = [dict objectForKey:#"name"];
detileName = [dict objectForKey:#"detailName"];
itmsLink = [dict objectForKey:#"itms-serviceLink"];
icon = [dict objectForKey:#"icon"];
developer = [dict objectForKey:#"developer"];
version = [dict objectForKey:#"version"];
category = [dict objectForKey:#"category"];
rating = [dict objectForKey:#"rating"];
ratingNumbers = [dict objectForKey:#"ratingNumber"];
description = [dict objectForKey:#"description"];
developerEmails = [dict objectForKey:#"developerEmail"];
cell.AppName.text = name;
cell.category.text = category;
cell.rater.text = [NSString stringWithFormat:#"(%#)", ratingNumbers];
if ([rating intValue] == 1) {
cell.rating.image = [UIImage imageNamed:#"1.png"];
}
if ([rating intValue] == 2) {
cell.rating.image = [UIImage imageNamed:#"2.png"];
}
if ([rating intValue] == 3) {
cell.rating.image = [UIImage imageNamed:#"3.png"];
}
if ([rating intValue] == 4) {
cell.rating.image = [UIImage imageNamed:#"4.png"];
}
cell.itms = itmsLink;
[NSURLConnection sendAsynchronousRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:icon]] queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse* response, NSData* data, NSError* error){
if(error)
{
// Error Downloading image data
cell.AppIcon.image = [UIImage imageNamed:#"placeholder.png"];
}
else
{
[cell.AppIcon setImage:[UIImage imageWithData:data]];
}
}];
cell.AppIcon.image = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:icon]]];
cell.number.text = [NSString stringWithFormat:#"%li", (long)indexPath.row + 1];
}];
cell.AppIcon.layer.masksToBounds = YES;
cell.AppIcon.layer.cornerRadius = 16.0;
cell.installButton.layer.masksToBounds = YES;
cell.installButton.layer.cornerRadius = 5.0f;
cell.installButton.layer.borderColor = [UIColor darkGrayColor].CGColor;
cell.installButton.layer.borderWidth = 1.0f;
return cell;
}

Answer 1

Since you're fetching from JSON, the server you got it from may not sort your data for you. Course its impossible for us to know what its doing without you divulging into the the server's APIs.
What you can do, without giving further info is just do a sort after you receive new data from the server:
NSSortDescriptor *descriptor = [[NSSortDescriptor alloc] initWithKey:#"name" ascending:YES];
NSArray *sortedApplicationArray = [application sortedArrayUsingDescriptors:#[descriptor]];
application = sortedApplicationArray;
Just don't put that code inside your cellForRowAtIndexPath, cos it'll do a sort each time a row is created!
I think I know what the problem is.
You have an asynchronous operation in your cellForRowAtIndexPath. You should set the cell UI elements directly with the dict object and outside the operation queue.
The only thing that looks like it needs to be done asynchronously is the image download. I recommend you use SDWebImage from github for that, it handles the download in its own queue and caches the image in memory and on disk.