self.revealViewController() error returning nil

Question

i have to code an application for school project that we have to get a library of PDF with categories and a detail view of a selected PDF. The problem is that when i select a category the application crash and i get this error "fatal error: unexpectedly found nil while unwrapping an Optional value" I have noticed that's when i reload data f this view that it crashes. The line where i get the error is Open.target = self.revealViewController()

Here's my entire file :

//
//  TableViewControllertest.swift
//  ProjetSwift
//
//  Created by geoffrey dalfin on 08/04/2016.
//  Copyright © 2016 geoffrey dalfin. All rights reserved.
//

import UIKit
import Alamofire

class TableViewControllertest: UITableViewController {

@IBOutlet weak var titrePDF: UILabel!
@IBOutlet weak var Open: UIBarButtonItem!

@IBOutlet weak var titleView: UINavigationItem!
var TabPDF = [Dictionary<String, AnyObject>]()
var selectedCategorie = String("")




override func viewDidLoad() {
    if selectedCategorie == "" {
        loadDataPDF()
    } else {
        LoadPDFCateorie(selectedCategorie)
    }

    super.viewDidLoad()
    tableView.delegate = self
    tableView.dataSource = self
    Open.target = self.revealViewController() ***<== ERROR COMES FROM HERE***
    //Quand on clique dessus, sa on appele le revealViewController
    Open.action = Selector("revealToggle:")

    // Uncomment the following line to preserve selection between presentations
    // self.clearsSelectionOnViewWillAppear = false

    // Uncomment the following line to display an Edit button in the navigation bar for this view controller.
    // self.navigationItem.rightBarButtonItem = self.editButtonItem()
}

func loadDataPDF(){
    Alamofire.request(.GET, "http://perso.montpellier.epsi.fr/~geoffrey.dalfin/ProjetE4/requetes/ListePDF.php").responseJSON{
        response in switch response.result{
        case.Success:
            if let PDF = response.result.value as? [Dictionary<String, AnyObject>]{
                self.TabPDF = PDF
                self.tableView.reloadData()
            }
        case.Failure(let error):
            print(error)
        }
    }
}

override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    // #warning Incomplete implementation, return the number of rows
    return TabPDF.count
}

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

    let cellule = tableView.dequeueReusableCellWithIdentifier("cellule" ,forIndexPath: indexPath) as! TableViewCell
    let P = TabPDF[indexPath.row]
    cellule.titrePDF?.text = P["Nom"] as? String
    return cellule
}


override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if segue.identifier == "detail" {
        var details = segue.destinationViewController as!ViewDetailPDF

        var indexPath = NSIndexPath()

        indexPath = self.tableView.indexPathForSelectedRow!;

        details.test = ((TabPDF[indexPath.row] as! [String: AnyObject]))

    }
}


func LoadPDFCateorie(categorie : String){
    print(categorie)
    Alamofire.request(.GET, "http://perso.montpellier.epsi.fr/~geoffrey.dalfin/ProjetE4/requetes/RequeteCategorie.php?categorie="+categorie).responseJSON{
        response in switch response.result{
        case.Success:
            print(String(response.result.value))
            if let PDF = response.result.value as? [Dictionary<String, AnyObject>]{
                self.TabPDF = PDF
                self.tableView.reloadData()
            }
        case.Failure(let error):
            print(error)
        }

    }
}






 // 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?) {
 // Get the new view controller using segue.destinationViewController.
 // Pass the selected object to the new view controller.
    if (segue.identifier == "detail") {
        // pass data to next view
        var nextScene =  segue.destinationViewController as! ViewDetailPDF

        if let indexPath = self.tableView.indexPathForSelectedRow! {
        // Pass the selected object to the new view controller
            let selectedPDF = TabPDF[indexPath.row]
            nextScene.DetailPDF = selectedPDF
        }
    }
 }*/
 /*  override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) { // Fonction pour passer des données d'un controller à un autre
    let destViewController : ViewDetailPDF = segue.destinationViewController as! ViewDetailPDF
    let selectedIndex = self.tableView.indexPathForCell(sender as! UITableViewCell)
    destViewController.DetailPDF = TabPDF // On fait passer nos notes
}*/




}

i have a file with the function in it but it has been developed by a friend using a plugin so i hope this is the good part of the file:

   @protocol SWRevealViewControllerDelegate<NSObject>

   @optional

   // The following delegate methods will be called before and after                                                   the front view moves to a position
   - (void)revealController:(SWRevealViewController *)revealController                   willMoveToPosition:(FrontViewPosition)position;
   - (void)revealController:(SWRevealViewController *)revealController        didMoveToPosition:(FrontViewPosition)position;

   // This will be called inside the reveal animation, thus you can use        it to place your own code that will be animated in sync
   - (void)revealController:(SWRevealViewController *)revealController animateToPosition:(FrontViewPosition)position; 

Answer 1

self.revealViewController() returns the parent controller of type SWRevealViewController.

If your controller is not in the view hierarchy of a SWRevealViewController, the method will return nil.

In viewDidLoad your controller has no parents and revealViewController() will always return nil.

You should call revealViewController() only when your controller is visible, that means in viewDidAppear:. Never in viewDidLoad.