Pull To Refresh a table view in SWIFT - ios

Question

I am totally new to SWIFT and to developing in general. I am currently building an RSS news feed to hone my (very limited) skills. I am basically parsing an RSS feed from a random news channel and then storing the titles in a simple table view.
I am trying to implement UIPullToRefresh using SWIFT, and truth be told I am kinda stuck! I have written the following code. As you can see I have added the necessary code to my viewDidLoad method. At this point the refresh spinner works well but I am now wondering what code is needed in my "refresh function" to actually refresh my table view.
I know this may seem trivial to most of you guys, but i am fairly new to this and i have been pulling my hair for the last 12 hours ... so anything would probably help at this point.
Thanks for your help!
import UIKit
class BRTableViewController: UITableViewController, NSXMLParserDelegate {
var parser: NSXMLParser = NSXMLParser()
var blogPosts: [BlogPost] = []
var postTitle: String = String()
var postLink: String = String()
var postDate: String = String()
var eName: String = String()
override func viewDidLoad() {
super.viewDidLoad()
let url:NSURL = NSURL(string: "http://rt.com/rss/")!
parser = NSXMLParser(contentsOfURL: url)!
parser.delegate = self
parser.parse()
// pull to refresh the table view
refreshControl!.attributedTitle = NSAttributedString(string: "Pull to refresh")
refreshControl!.addTarget(self, action: "refresh:", forControlEvents: UIControlEvents.ValueChanged)
tableView.addSubview(refreshControl!)
}
func refresh(sender:AnyObject){
let url:NSURL = NSURL(string: "http://rt.com/rss/")!
parser = NSXMLParser(contentsOfURL: url)!
parser.delegate = self
parser.parse()
}
// MARK: - NSXMLParserDelegate methods
func parser(parser: NSXMLParser!, didStartElement elementName: String!, namespaceURI: String!, qualifiedName qName: String!, attributes attributeDict: [NSObject : AnyObject]!) {
eName = elementName
if elementName == "item" {
postTitle = String()
postLink = String()
postDate = String()
}
}
func parser(parser: NSXMLParser!, foundCharacters string: String!) {
let data = string.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet())
if (!data.isEmpty) {
if eName == "title" {
postTitle += data
} else if eName == "link" {
postLink += data
} else if eName == "pubDate" {
postDate += data
}
}
}
func parser(parser: NSXMLParser!, didEndElement elementName: String!, namespaceURI: String!, qualifiedName qName: String!) {
if elementName == "item" {
let blogPost: BlogPost = BlogPost()
blogPost.postTitle = postTitle
blogPost.postLink = postLink
blogPost.postDate = postDate
blogPosts.append(blogPost)
}
}
override func parser(parser: NSXMLParser!, didEndElement elementName: String!, namespaceURI: String!, qualifiedName qName: String!) {
if elementName == "item" {
self.tableView.reloadData();
self.refreshControl.endRefreshing();
}
}
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 blogPosts.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as UITableViewCell
let blogPost: BlogPost = blogPosts[indexPath.row]
cell.textLabel.text = blogPost.postTitle
cell.detailTextLabel?.text = blogPost.postDate.substringToIndex(advance(blogPost.postDate.startIndex, 25))
return cell
}
override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return 50.0
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {
if segue.identifier == "viewpost" {
let selectedRow = tableView.indexPathForSelectedRow()?.row
let blogPost: BlogPost = blogPosts[selectedRow!]
let viewController = segue.destinationViewController as PostViewController
viewController.postLink = blogPost.postLink
}
}
}

Answer 1

I think this fix the issue:
func refresh(sender:AnyObject){
parser = NSXMLParser(contentsOfURL: url)!
parser.delegate = self
parser.parse()
}
This will re-parse the XML and update the blogPosts variable.
Remove the following line in viewDidLoad:
refreshControl = UIRefreshControl()
You should also override the parserDidEndDocument function to include this:
func parserDidEndDocument(parser: NSXMLParser!){
self.tableView.reloadData();
self.refreshControl?.endRefreshing();
}
This will refresh the table view once the parser is done.