iOS Development - Framework Basics 2

1 Agenda

• More UIKit
  • UITableViewController
    • UITableViewDelegate Protocol
    • UITableViewDataSource Protocol
  • UITableView
  • UITableViewCell

2 UITableViewController

3 UITableViewDelegate

• The UITableViewDelegate Protocol defines methods that are to be implemented in order to for example:
  • Manage and handle selections
  • Configure Rows, e.g. the height of a row
  • Modifying Header and Footer of Sections
  • Managing TableView highlighting
  • Editing, Copy/Paste and reordering TableRows

4 UITableViewDelegate

• Example:
  • To handle row selection, override the following method of the UITableViewDelegate Protocol in the UITableViewController:

override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    print("Selected row \(indexPath.item)")
}

• Parameters:
  • tableView: the selected TableView (relevant only, if multiple Tables are handled by this class)
  • indexPath: the index of the selected row. The item property contains an int with the row number

5 UITableViewDataSource

• The UITableViewDataSource Protocol mediates between the Data Model and the TableView
• Works similar to the ListAdapter on Android and defines a number of methods that the UITableViewController implements in order to fill the Table with content, e.g. methods to
  • Get the number of sections in a table
  • Get the number of rows in a section
  • Get the cell for a certain row

6 UITableViewDataSource

• Example methods implemented in the UITableViewController:

// Override to define the number of sections for the table
override func numberOfSections(in tableView: UITableView) -> Int {
    // #warning Incomplete implementation, return the number of sections
    return 1
}

// Override to define the number of rows in each section
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    // #warning Incomplete implementation, return the number of rows
    return shoppingList.count
}

// Override to define the cell for a given row
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "reuseIdentifier", for: indexPath)

    // Configure the cell...
   var config = cell.defaultContentConfiguration()
        config.text = shoppingList[indexPath.item]
        config.image = UIImage(systemName: "applelogo")
        config.secondaryText = "Edeka"
        
        cell.contentConfiguration = config

//old way - deprecated
    //cell.textLabel?.text = shoppingList[indexPath.item]

    return cell
}

7 UITableView

8 UITableViewCell

9 References

• iOS Dev Center: developer.apple.com
• iOS Reference Library: http://developer.apple.com/library/ios/navigation/