Search Bar crashing app when inputting characters - swift

Question

I have a UITableView that is populating locations and a Search Bar set as the header of that UITableView.
Whenever certain characters are entered, or a certain amount of characters are entered, the app crashes, giving me no error code.
Sometimes the app crashes after inputting one character, maybe 2 characters, maybe 3, or maybe 4. There seems to be no apparent reason behind the crashing.
The search function properly searches and populates the filtered results, but for no apparent reason, crashes if a seemingly arbitrary amount of characters are inputted.
I have tried using the exception breakpoint tool already, and it is providing me with no new information. I think it has something to do with if there are no search results.
override func viewDidLoad() {
super.viewDidLoad()
searchController.searchResultsUpdater = self
searchController.dimsBackgroundDuringPresentation = false
searchController.searchBar.placeholder = "Search Locations..."
navigationItem.hidesSearchBarWhenScrolling = false
searchController.hidesNavigationBarDuringPresentation = false
locationTableView.tableHeaderView = searchController.searchBar
searchController.searchBar.sizeToFit()
searchController.searchBar.showsCancelButton = false
searchController.searchBar.barTintColor = UIColor.white
filteredData = locationList
// Sets this view controller as presenting view controller for the search interface
definesPresentationContext = true
locationList = createArray()
// Reload the table
let range = NSMakeRange(0, self.locationTableView.numberOfSections)
let sections = NSIndexSet(indexesIn: range)
self.locationTableView.reloadSections(sections as IndexSet, with: .fade)
}
func updateSearchResults(for searchController: UISearchController) {
filterContentForSearchText(searchController.searchBar.text!)
}
func searchBarIsEmpty() -> Bool {
// Returns true if the text is empty or nil
return searchController.searchBar.text?.isEmpty ?? true
}
func filterContentForSearchText(_ searchText: String) {
filteredData = locationList.filter({( locationName : Location) -> Bool in
return locationName.locationName.lowercased().contains(searchText.lowercased())
})
let range = NSMakeRange(0, self.locationTableView.numberOfSections)
let sections = NSIndexSet(indexesIn: range)
self.locationTableView.reloadSections(sections as IndexSet, with: .fade)
}
func isFiltering() -> Bool {
return searchController.isActive && !searchBarIsEmpty()
}
func locationTableView(_ locationTableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if isFiltering() {
return filteredData.count
}
return locationList.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let locationCell = locationTableView.dequeueReusableCell(withIdentifier: "locationCell", for: indexPath) as! locationCell
let location: Location
if isFiltering() {
location = filteredData[indexPath.row]
} else {
location = locationList[indexPath.row]
}
locationCell.setLocation(location: location)
return locationCell
}
The expected result is that the UITableView should populate with filtered results. Instead, it populates them and crashes if too many characters are inputted (usually 1-4 characters).
EDIT 1: I have found through debugging the error:
Thread 1: EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0)
appears on Line 2 on this block of code:
if isFiltering() {
location = filteredData[indexPath.row]
} else {
location = locationList[indexPath.row]
}
EDIT 2: This is the tutorial I used.
https://www.raywenderlich.com/472-uisearchcontroller-tutorial-getting-started

Answer 1

Seems like you are expecting the tableView to provide YOU with the number of sections... it is supposed to be driven by your own datasource.
Since you are not providing a numberOfSections in your data source I'm assuming it is 1. If all of your rows are in 1 section, all of the nifty reloading you are doing could be greatly simplified.
I suggest you read up on UITableView dataSource protocol at https://developer.apple.com/documentation/uikit/uitableviewdatasource
Reviewing the tutorial you are reading, it seems it is using a reloadData() which forces the tableView to ignore previous number of rows and reload its content with a new number of rows. And based on your findings so far, I would assume that is part of the root cause, with the tableview wrongly assuming a pre-determined number of rows and attempting to retrieve cells that are no longer within range.