Bar Button Nil After Pressing Switch in Swift? - ios

Question

Ok here is what is going on. I have a table view class called MainTabeViewController. I have a sidebar class called SettingsSidebarViewController that uses SW Reveal to show a menu. The menu is toggled by a bar button item called settings. The menu works fine with the bar button item, and when you press it the menu toggles like it should.
However, once I click a switch, the app crashes and I start getting a EXC_BAD_INSTRUCTION error that reads in the console Fatal error: unexpectedly found nil while unwrapping an optional value. Why is the bar button item suddenly nil after the switch is pressed?
MAINTABLEVIEWCONTROLLER.swift
import UIKit
import SwiftyJSON
class MainTableViewController: UITableViewController, SettingsSidebarViewDelegate {
//HEERE IS THE BAR BUTTON ITEM CALLED SETTINGS <- <- <-
#IBOutlet var settings: UIBarButtonItem!
var NumberofRows = 0
var names = [String]()
var descriptions = [String]()
var categories = [String]()
var types = [String]()
var series = [String]()
var groups = [String]()
func parseJSON(){
let path = NSBundle.mainBundle().URLForResource("documents", withExtension: "json")
let data = NSData(contentsOfURL: path!) as NSData!
let readableJSON = JSON(data: data)
NumberofRows = readableJSON["Documents"].count
for i in 1...NumberofRows {
let doc = "Doc" + "\(i)"
let Name = readableJSON["Documents"][doc]["name"].string as String!
let Description = readableJSON["Documents"][doc]["description"].string as String!
let Category = readableJSON["Documents"][doc]["category"].string as String!
let Type = readableJSON["Documents"][doc]["type"].string as String!
let Series = readableJSON["Documents"][doc]["tags"]["series"].string as String!
let Group = readableJSON["Documents"][doc]["tags"]["group"].string as String!
names.append(Name)
descriptions.append(Description)
categories.append(Category)
types.append(Type)
series.append(Series)
groups.append(Group)
}
}
Here is where the errors start to occur AFTER the switch is pressed (still in same class)
func initSettings(){
//Sets button title to gear, sets button actions (to open menu)
settings.title = NSString(string: "\u{2699}\u{0000FE0E}") as String!
let font = UIFont.systemFontOfSize(25);
settings.setTitleTextAttributes([NSFontAttributeName: font], forState:UIControlState.Normal)
settings.target = self.revealViewController()
settings.action = #selector(SWRevealViewController.rightRevealToggle(_:))
self.view.addGestureRecognizer(self.revealViewController().panGestureRecognizer())
}
func showTags(showTags: Bool) {
tableView.reloadData()
}
func showTimestamp(showTimeStamp: Bool) {
tableView.reloadData()
}
override func viewDidLoad() {
super.viewDidLoad()
parseJSON()
initSettings()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - Table view data source
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return NumberofRows
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("MainTableCell", forIndexPath: indexPath) as! MainTableViewCell
if names.count != 0{
cell.fileName.text = names[indexPath.row]
cell.fileDescription.text = descriptions[indexPath.row]
cell.fileCategory.text = categories[indexPath.row]
cell.fileType.text = types[indexPath.row]
cell.options.setTitle(NSString(string: ":") as String!, forState: .Normal)
cell.tag1.text = series[indexPath.row]
cell.tag2.text = groups[indexPath.row]
if showTagsVal{
cell.tag1.hidden = false
}
else{
cell.tag1.hidden = true
}
if showTimeStampVal{
cell.tag2.hidden = false
}
else{
cell.tag2.hidden = true
}
}
return cell
}
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
self.performSegueWithIdentifier("showView", sender: self)
}
// MARK: - Navigation
//In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if(segue.identifier == "showView"){
let detailVC: DetailViewController = segue.destinationViewController as! DetailViewController
let indexPath = self.tableView.indexPathForSelectedRow!
detailVC.text = names[indexPath.row]
self.tableView.deselectRowAtIndexPath(indexPath, animated: true)
}}}
SettingsSidebarViewController.swift
import UIKit
protocol SettingsSidebarViewDelegate{
func showTags(showTags: Bool);
func showTimestamp(showTimeStamp: Bool)
}
var showTagsVal = false
var showTimeStampVal = false
class SettingsSidebarViewController: UIViewController {
var delegate: SettingsSidebarViewDelegate! = nil
#IBOutlet weak var sidebar_title: UILabel!
#IBOutlet var showTagsSwitch: UISwitch!
#IBOutlet var showTimestampSwitch: UISwitch!
#IBAction func switchPressed(sender: AnyObject) {
let storyBoard : UIStoryboard = UIStoryboard(name: "Main", bundle:nil)
let nextViewController = storyBoard.instantiateViewControllerWithIdentifier("main") as! MainTableViewController
self.presentViewController(nextViewController, animated:true, completion:nil)
let vc = MainTableViewController()
self.delegate = vc
if showTagsSwitch.on{
showTagsVal = true
delegate.showTags(showTagsVal)
}
else{
showTagsVal = false
delegate.showTags(showTagsVal)
}
if showTimestampSwitch.on{
showTimeStampVal = true
delegate.showTimestamp(showTimeStampVal)
}
else{
showTimeStampVal = false
delegate.showTimestamp(showTimeStampVal)
}
}
override func viewDidLoad() {
super.viewDidLoad()
sidebar_title.text = "Settings"
// Do any additional setup after loading the view.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
Help is appreciated! I am sure this is a question concerning transitioning view controllers that is something easy but I have tried too long to figure it out.

Answer 1

Your problem is you are creating a new instance of MainTableViewController and assigning it to delegate. That's why the bar button item is nil, because all the initialization and binding isn't done.
You have to change the delegate and assign the view controller you already got with instantiateViewControllerWithIdentifier:
self.delegate = nextViewController