Get data in batches & store it in NSMutableArray to display it in UITableView in iphone

Question

How can I get the data from address book in batches of say 20 records at a time & display that 20 records in table view. When new 20 records are fetched , I want to add it in existing array & reload the data. How can I do this? Thanks

Answer 1

In the following delegate where you are setting your rows add one extra row

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return yourMutableArray.count+1;
}

The following delegate tells you that currently which cell is being created.

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath;

Under this you can add a check condition like

if(indexPath.row > yourMutableArray.count)
{

  // This means you are at the end of your table
  // Call your webservice here and append the next set of data into the yourMutableArray
  // You can also show an activity indicator over the extra cell here, Indicating the loading of new data
   [self performSelector:@selector(getDataFromWebservice) withObject:nil afterDelay:1.0];
}
else
{
  // Do your cell settings here
}

and somewhere in your code where you are checking for the success of your webserivce add the following line to reload the table

[yourTable reloadData];

Make sure, that you append the new data into your MutableArray, else table will show only the latest data from the webservice. Hope, this will help you.