 extension NewsViewController: MWFeedParserDelegate {
 
     func feedParser(_ parser: MWFeedParser!, didParseFeedItem item: MWFeedItem!) {
-        feedItems.append(item)
+        parsingFeedItems?.append(item)
     }
 
     func feedParserDidFinish(_ parser: MWFeedParser!) {

private extension NewsViewController {

    @objc func parse() {
        parser?.stopParsing()
        feedItems = []

        parser = MWFeedParser(feedURL: URL(string: RSSFeedURL)!)
        parser?.delegate = self
        parser?.parse()
    }

}


class NewsViewController: UITableViewController {

    fileprivate let parser: MWFeedParser = MWFeedParser(feedURL: URL(string: RSSFeedURL)!)
    fileprivate var parsingFeedItems: [MWFeedItem]?
    fileprivate var feedItems = [MWFeedItem]()

    init() {
        super.init(style: .plain)
        title = "News"
        parser.delegate = self
    }

    required init?(coder aDecoder: NSCoder) {
