I show an error message when I parse XML - ios

Question

I am new to Swift programming. I have 2 classes to parse RSS and show the datas. It's named ParseRSSFeed and DetailVC. But I can't see the datas in TableView when I want to parse.
But if I call methods of XMLParserDelegate in DetailVC, it works. Probably I did a mistake while calling the methods from another class.
My code is as below.
What did I overlook?
ParseRSSFeeds class to parse XML
import UIKit
class ParseRSSFeeds: XMLParser, XMLParserDelegate{
var parser = XMLParser()
var news = NSMutableArray()
var elements = NSMutableDictionary()
var element = NSString()
var header = NSMutableString()
var link = NSMutableString()
var desc = NSMutableString()
var date = NSMutableString()
func parseFromUrl(){
news = []
parser = XMLParser(contentsOf: NSURL(string: "https://www.wired.com/feed/rss")! as URL)!
parser.delegate = self
parser.parse()
}
func parser(_ parser: XMLParser, didStartElement elementName: String, namespaceURI: String?, qualifiedName qName: String?, attributes attributeDict: [String : String] = [:]) {
element = elementName as NSString
if (elementName as NSString) .isEqual(to: "item") {
elements = NSMutableDictionary()
elements = [:]
header = NSMutableString()
header = ""
link = NSMutableString()
link = ""
desc = NSMutableString()
desc = ""
date = NSMutableString()
date = ""
}
}
func parser(_ parser: XMLParser, foundCharacters string: String) {
if element .isEqual(to: "title"){
header.append(string)
}else if element .isEqual(to: "link"){
link.append(string)
}else if element .isEqual(to: "description"){
desc.append(string)
}else if element .isEqual(to: "pubDate") {
date.append(string)
}
}
func parser(_ parser: XMLParser, didEndElement elementName: String, namespaceURI: String?, qualifiedName qName: String?) {
if (elementName as NSString) .isEqual(to: "item") {
if !header .isEqual(nil) {
elements.setObject(header, forKey: "title" as NSCopying)
}
if !link .isEqual(nil) {
elements.setObject(link, forKey: "link" as NSCopying)
}
if !desc .isEqual(nil) {
elements.setObject(desc, forKey: "description" as NSCopying)
}
if !date .isEqual(nil) {
elements.setObject(date, forKey: "pubDate" as NSCopying)
}
news.add(elements)
}
}
}
DetailVC (It includes table view to show RSS feeds.)
import UIKit
class DetailVC: UIViewController, UITableViewDelegate, UITableViewDataSource {
#IBOutlet weak var tblNews: UITableView!
let parser = ParseRSSFeeds()
override func viewDidLoad() {
super.viewDidLoad()
ParseRSSFeeds().parseFromUrl()
tblNews.reloadData()
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return parser.news.count - parser.news.count + 5
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
var cell = tblNews.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
if cell .isEqual(NSNull.self) {
cell = Bundle.main.loadNibNamed("cell", owner: self, options: nil)?[0] as! UITableViewCell
}
cell.textLabel?.text = (parser.news.object(at: indexPath.row) as AnyObject).value!(forKey: "title") as? String
cell.detailTextLabel?.text = (parser.news.object(at: indexPath.row) as AnyObject).value!(forKey: "description") as? String
return cell
}
}

Answer 1

You have two ParseRSSFeeds instances, the parser property and the one you create in viewDidLoad. So, viewDidLoad is creating a second instance of ParseRSSFeeds, requesting and parsing the response, and then discarding those results, leaving the separate parser property untouched.
You should instead have viewDidLoad reference the parser property rather than creating new instance of ParseRSSFeeds:
override func viewDidLoad() {
super.viewDidLoad()
parser.parseFromUrl()
...
}