Todo app crash error comes back with NIL? xcode - ios

Question

So, I have been building this project that is a todo app. and when you click on a cell your item should be searched on to ask.com. I now keep getting this fatal error. And it shows up as nil in my "Appurl" part of the code as you can see in my code. When I click on it in the code it shows up as nil which is weird. Moreover, it is causing my app to crash. Source code would be amazing. I have no idea how to fix this. all I know is that the nil shows up in the "Appurl" The fatal error message that comes up is as follows below. I have looked up other answer for this type of fatal error message with no luck.
"thread 1: Fatal error: Unexpectedly found nil while unwrapping an Optional value"
import UIKit
class NewTableViewController: UITableViewController, NewCellDelegate, {
var news:[News]!
override func viewDidLoad() {
super.viewDidLoad()
loadData()
func loadData() {
news = [News]()
news = DataManager.loadAll(News.self).sorted(by: {$0.createdAt < $1.createdAt})
self.tableView.reloadData()
}
#IBAction func Save(_ sender: Any) {
let addAlert = UIAlertController(title: "ADD", message: "TODO", preferredStyle: .alert)
addAlert.addTextField { (textfield:UITextField) in
textfield.placeholder = "TODO"
}
addAlert.addAction(UIAlertAction(title: "Save", style: .default, handler: { (action:UIAlertAction) in
guard let title = addAlert.textFields?.first?.text else {return}
let newsave = News(title: title, completed: false, createdAt: Date(), itemIdentifier: UUID())
newsave.saveItem()
self.news.append(newsave)
let indexPath = IndexPath(row: self.tableView.numberOfRows(inSection: 0), section: 0)
self.tableView.insertRows(at: [indexPath], with: .automatic)
}))
addAlert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
self.present(addAlert, animated: true, completion: nil)
}
};
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - Table view data source
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of rows
return news.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! NewTableViewCell
cell.delegte = self
let news = self.news[indexPath.row]
cell.label.text = news.title
return cell
}
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath){
//getting the index path of selected row
let indexPath = tableView.indexPathForSelectedRow
//getting the current cell from the index path
let currentCell = tableView.cellForRow(at: indexPath!) as! NewTableViewCell
//getting the text of that cell
let TODO = currentCell.label.text
let appURL = NSURL(string: "https://www.ask.com/web?q=\
(TODO))&o=0&qo=homepageSearchBox)")
if UIApplication.shared.canOpenURL(appURL! as URL) {
if #available(iOS 10.0, *) {
UIApplication.shared.open(appURL! as URL, options: [:], completionHandler: nil)
} else {
UIApplication.shared.openURL(appURL! as URL)
}
}
}

Answer 1

You need to handle occurrence of spaces and special characters like + in you url string,
For handling spaces,
/**Handle occurance of space in given url string*/
class func handleSpaces(in urlString: String) -> String {
return urlString.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)!
}
For handling + symbol,
/**Handle occurance of space in given url string*/
class func handlePlusSign(in urlString: String) -> String {
return urlString.replacingOccurrences(of: "+", with: "%2B")
}
To avoid crashes you need to use proper crash resisting conditions like if let and guard let in your app,
e.g
if let url = appURL {
// Proceed to use this url
}
Your code will become,
let indexPath = tableView.indexPathForSelectedRow
//getting the current cell from the index path
guard let currentCell = tableView.cellForRow(at: indexPath!) as? NewTableViewCell else {
print("Can't get your cell")
return
}
//getting the text of that cell
guard let todo = currentCell.label.text else {
print("Error in getting todo string")
return
}
var urlString = "https://www.ask.com/web?q=\(todo))&o=0&qo=homepageSearchBox)"
urlString = urlString.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)! // Handle spaces in your `todo` string.
guard let appURL = URL(string: urlString) else {
print("Can't form url")
return
}
if UIApplication.shared.canOpenURL(appURL) {
if #available(iOS 10.0, *) {
UIApplication.shared.open(appURL, options: [:], completionHandler: nil)
} else {
UIApplication.shared.openURL(appURL)
}
}
Thanks.