I've a UITableViewDataSource which maintains sections of data items which will be presented by an UITableView instance. The table view is editable, allowing insertion and deletion of rows and sections, and all changes on the view should be written back to the data source. After reading through the Apple documents, I can deal with insertion and deletion on rows by sending message tableView:commitEditingStyle:forRowAtIndexPath: to the data source.
But, however, I can't figure out what is the standard way to feedback the changes on sections to the data source. Please kindly help.
The delegate method tableView:commitEditingStyle:forRowAtIndexPath: is called by the table view to tell you what the user has done (what they have added / removed). It is then the responsibility of your code to make the appropriate changes to your Model and reload the table view.
The simplest way to reload is to call reloadData, and you also have more specific options for reloading / inserting / removing individual rows or sections - this is all from a UI perspective and the table view requires that you have updated your Model before you call any of these methods or the table view will throw an exception.