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Organizing data

Organizing data. So far, we have hard coded the table data We should have a model for that For example 2 parallel arrays: A 1-dim array of strings, the section headers A 2-dim array of strings, the row headers. Organizing data.

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Organizing data

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  1. Organizing data • So far, we have hard coded the table data • We should have a model for that • For example 2 parallel arrays: • A 1-dim array of strings, the section headers • A 2-dim array of strings, the row headers

  2. Organizing data • It is much easier to code all the previous methods setting up the table view with such data structures

  3. 2-dim array for the table data • You can use _objects (already coded) or use your own array instance variable • If array name is toc (i.e. table of contents), a 2-dim array of strings • # of sections = [toc count] • # of rows per section = [[toc objectAtIndex: section] count] • Need parallel single-dim array for section titles

  4. Organizing data • For method setting text for all cells, use • [[toc objectAtIndex: indexPath.section] objectAtIndex: indexPath.row] • Be careful about the didSelect.. method • NSDate *object = _objects[indexPath.row]; •  may CRASH your app if you used _objects and did not organize _objects as the template expects

  5. Universal App • We may also want to have a different View Controller for the iPhone version (different dimensions) • We can keep the DetailViewController for the iPad version

  6. Universal App • Add a New File, a subclass of UIViewController, name it IPhoneDetailViewController, with or without a XIB file • In the .h file, add instance variables section, row, subChapter, and the method setSection:Row:SubChapter: • Implement the method in the .m file

  7. Universal App • In MasterViewController’s tableView:didSelectRowAtIndexPath: method, add an else block (iPhone scenario) • In it, instantiate an IPhoneDetailViewController, push it, call setSection:Row:SubChapter: • We also need to put something in the detail View, say a label with section, row and subChapter: we code an update method for that

  8. UINavigationController • A UIViewController (the superclass of UITableViewController) has a UINavigationController property; it manages the presentation of hierarchical views • It is the navigation controller that pushes the detail view controller

  9. In else block • // Create a IPhoneDetailViewController • IPhoneDetailViewController *ipdvc = [[IPhoneDetailViewController alloc] init]; • // Push it onto stack • [self.navigationController pushViewController: ipdvc animated:YES];

  10. In else block • // call setSection:…. • [ipdvc setSection: indexPath.section Row:indexPath:row SubChapter: [[toc objectAtIndex: indexPath.section] objectAtIndex: indexPath.row]; • // update detail View • [ipdvc update];

  11. Update method • // Create a label • CGRect frame = … • UILabel *label = … • // set label’s text and add it to the View • label.text = [NString stringWithFormat: @”section %d, row %d, %@”, section, row, subChapter]; • [self.view addSubview: label];

  12. Undo the magic • When we run, we are still going to the existing View of the template (via the segue from the table View) • In Main_iPhone.storyboard, delete the segue between the master View and the detail View (no longer used)

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