An example of guard statement awesomeness.

guarding.swift

class MyViewController : UITableViewController {
    // ...
    override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
        let activity = self.activities
        // If anything isn't right, deselect the row and exit.
        guard activity.openable else {
            tableView.deselectRowAtIndexPath(indexPath, animated: true)
            return
        }
        guard let task = self.getTask(activity) else {
            tableView.deselectRowAtIndexPath(indexPath, animated: true)
            return
        }
        
        // Looks like everything is fine. That means we can open up the detail view.
        let taskViewController = DetailViewController(task: task, taskRunUUID: NSUUID(), identifier: activity.identifier)
        taskViewController.delegate = self
        navigationController?.presentViewController(taskViewController, animated: true, completion: nil)
    }
}