UISearchBar crashing after filtering in Swift - swift

Question

I'm trying to make my app iOS 7 compatible with a search bar. So that means I can't use UISearchController (like I would far prefer to be doing). So I'm trying to implement the search bar with searchDisplayController. But whenever I run the app and enter text into the search bar, the app crashes.
I plugged in a few break points to see when exactly this is happening, and it seems that it happens at the numberOfRowsInSection function. Although I have no idea why that is because when I print to the console in this function, right before crash the filtered data array is what I would expect it to be given the input text in the status bar.
So here is my code. Maybe I'm missing something. A second set of eyes on this is greatly appreciated. Thanks!
class RegData2: UITableViewController, UISearchBarDelegate, UISearchDisplayDelegate {
// Beginning to ios7 compatibility
let model = Model()
var prevArray = [String]()
var selectionPrev = String()
var selection : String = ""
var filteredTableData = [String]()
var int = 0
override func viewDidLoad() {
super.viewDidLoad()
// Reload the table
self.tableView.reloadData()
}
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if (tableView == self.searchDisplayController?.searchResultsTableView) {
return self.filteredTableData.count
}
else {
return prevArray.count
}
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell") as UITableViewCell!
cell.textLabel?.font = UIFont.boldSystemFontOfSize(18)
if (tableView == self.searchDisplayController?.searchResultsTableView) {
cell.textLabel?.text = filteredTableData[indexPath.row]
return cell
}
else {
cell.textLabel?.text = prevArray[indexPath.row]
return cell
}
}
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath)
{
tableView.deselectRowAtIndexPath(indexPath, animated: true)
// controller.searchBar.resignFirstResponder()
if (tableView == self.searchDisplayController?.searchResultsTableView) {
selection = filteredTableData[indexPath.row]
}
else {
selection = prevArray[indexPath.row]
}
performSegueWithIdentifier("regData2ToRegView", sender: self)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "regData2ToRegView" {
let regView = segue.destinationViewController as! RegView
regView.prevSelection = selection
regView.prevSelectionType = selectionPrev
}
}
func filterContentForSearchText(searchText: String, scope: String = "Title") {
filteredTableData = prevArray.filter({( item : String) -> Bool in
var match = (scope == "Title")
var stringMatch = item.rangeOfString(searchText)
return match && (stringMatch != nil)
})
}
func searchDisplayController(controller: UISearchDisplayController, shouldReloadTableForSearchString searchString: String?) -> Bool {
self.filterContentForSearchText(searchString!, scope: "Title")
return true
}
func searchDisplayController(controller: UISearchDisplayController, shouldReloadTableForSearchScope searchOption: Int) -> Bool {
self.filterContentForSearchText(self.searchDisplayController!.searchBar.text!, scope: "Title")
return true
}
}