How to implant a sectioned tableview with Parse in Swift - xcode

Question

I am struggling to figure out how to implement a sectioned table view using parse. I am able to correctly section the table view if I don't load the names I want. However, when I use parse the names don't load in time and therefore are missed as it is async.
When I reload the table in queryFriends() it doesn't show up. My theory is that the table isn't sectioned again.
How do I make the table section again?
Or does anyone have any ideas?
Thanks for your help
import UIKit
import Parse
import Foundation
class MyFriendsTableView: UITableViewController, UITableViewDataSource, UITableViewDelegate{
var names:[String] = []
/*var names: [String] = [
"AAAA",
"Clementine",
"Bessie",
"Yolande",
"Tynisha",
"Ellyn",
"Trudy",
"Fredrick",
"Letisha",
"Ariel",
"Bong",
"Jacinto",
"Dorinda",
"Aiko",
"Loma",
"Augustina",
"Margarita",
"Jesenia",
"Kellee",
"Annis",
"Charlena",
"!##",
"###"
]*/
override func viewDidLoad() {
super.viewDidLoad()
self.refreshControl = UIRefreshControl()
self.refreshControl?.attributedTitle = NSAttributedString(string: "Pull to refresh")
self.refreshControl?.addTarget(self, action: "queryFriends", forControlEvents: UIControlEvents.ValueChanged)
self.tableView.addSubview(refreshControl!)
}
override func viewDidAppear(animated: Bool) {
UIApplication.sharedApplication().statusBarHidden = false
UIApplication.sharedApplication().statusBarStyle = UIStatusBarStyle.LightContent
queryFriends()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
func queryFriends() {
let currentUser = PFUser.currentUser()?.username
let predicate = NSPredicate(format: "status = 'Friends' AND fromUser = %# OR status = 'Friends' AND toUser = %#", currentUser!, currentUser!)
var query = PFQuery(className: "FriendRequest", predicate: predicate)
var friends:[String] = []
query.findObjectsInBackgroundWithBlock {
(objects: [AnyObject]?, error: NSError?) -> Void in
if error == nil {
if let objects = objects as? [PFObject] {
for object in objects {
if object["toUser"] as? String != currentUser {
friends.append(object["toUser"] as! String)
} else if object["fromUser"] as? String != currentUser {
friends.append(object["fromUser"] as! String)
}
}
}
} else {
// Log details of the failure
println("Error: \(error!) \(error!.userInfo!)")
}
self.names = friends
self.tableView.reloadData()
self.refreshControl?.endRefreshing()
}
}
/* type to represent table items
`section` stores a `UITableView` section */
class User: NSObject {
let name: String
var section: Int?
init(name: String) {
self.name = name
}
}
// custom type to represent table sections
class Section {
var users: [User] = []
func addUser(user: User) {
self.users.append(user)
}
}
// `UIKit` convenience class for sectioning a table
let collation = UILocalizedIndexedCollation.currentCollation()
as! UILocalizedIndexedCollation
// table sections
var sections: [Section] {
// return if already initialized
if self._sections != nil {
return self._sections!
}
// create users from the name list
var users: [User] = names.map { name in
var user = User(name: name)
user.section = self.collation.sectionForObject(user, collationStringSelector: "name")
return user
}
// create empty sections
var sections = [Section]()
for i in 0..<self.collation.sectionIndexTitles.count {
sections.append(Section())
}
// put each user in a section
for user in users {
sections[user.section!].addUser(user)
}
// sort each section
for section in sections {
section.users = self.collation.sortedArrayFromArray(section.users, collationStringSelector: "name") as! [User]
}
self._sections = sections
return self._sections!
}
var _sections: [Section]?
// table view data source
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return self.sections.count
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.sections[section].users.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let user = self.sections[indexPath.section].users[indexPath.row]
let cell = tableView.dequeueReusableCellWithIdentifier("UITableViewCell", forIndexPath: indexPath) as! UITableViewCell
cell.textLabel!.text = user.name
return cell
}
/* section headers
appear above each `UITableView` section */
override func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
// do not display empty `Section`s
if !self.sections[section].users.isEmpty {
return self.collation.sectionTitles[section] as? String
}
return ""
}
/* section index titles
displayed to the right of the `UITableView` */
override func sectionIndexTitlesForTableView(tableView: UITableView) -> [AnyObject] {
return self.collation.sectionIndexTitles
}
override func tableView(tableView: UITableView, sectionForSectionIndexTitle title: String, atIndex index: Int) -> Int {
return self.collation.sectionForSectionIndexTitleAtIndex(index)
}
}

Answer 1

You can try to clear the _sections in queryFriends:
self._sections = nil
self.names = friends
self.tableView.reloadData()
self.refreshControl?.endRefreshing()