Swift PHP post request set global variable from task - ios

Question

I successfully retrieve data from database by using post request. (I don't want to use get request cuz I want to send a verification to php.) Don't worry about the php part, it should be fine.
import UIKit
class mainPage: UIViewController, UITableViewDelegate, UITableViewDataSource {
#IBOutlet weak var tableView: UITableView!
#IBOutlet weak var toolBar: UIToolbar!
var values:NSArray = []
#IBOutlet weak var Open: UIBarButtonItem!
override func viewDidLoad() {
super.viewDidLoad()
Open.target = self.revealViewController()
Open.action = #selector(SWRevealViewController.revealToggle(_:))
self.view.addGestureRecognizer(self.revealViewController().panGestureRecognizer())
get()
}
func get(){
let request = NSMutableURLRequest(URL: NSURL(string: "http://www.percyteng.com/orbit/getAllpostsTest.php")!)
request.HTTPMethod = "POST"
let postString = "user=\("ios")"
request.HTTPBody = postString.dataUsingEncoding(NSUTF8StringEncoding)
let task = NSURLSession.sharedSession().dataTaskWithRequest(request) {
data, response, error in
if error != nil {
print("error=\(error)")
return
}
print("response = \(response)")
let array = try! NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers) as! NSArray
self.values = array
}
task.resume()
dispatch_async(dispatch_get_main_queue()) { tableView.reloadData()}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if values.count > 20{
return 20
}
else{
return values.count
}
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as!postCell
let maindata = values[values.count-1-indexPath.row]
if maindata["category"] as? String == "Services"{
cell.postImg.image = UIImage(named: "tile_services")
}
else if maindata["category"] as? String == "exchange"{
cell.postImg.image = UIImage(named: "tile_exchange")
}
else if maindata["category"] as? String == "Tutors"{
cell.postImg.image = UIImage(named: "tile_tutoring")
}
else if maindata["category"] as? String == "Sports"{
cell.postImg.image = UIImage(named: "tile_sports")
}
else if maindata["category"] as? String == "Sublet"{
cell.postImg.image = UIImage(named: "tile_sublet")
}
else if maindata["category"] as? String == "Events"{
cell.postImg.image = UIImage(named: "tile_events")
}
else{
cell.postImg.image = UIImage(named: "tile_carpool")
}
if maindata["category"] as? String == "Services" || maindata["category"] as? String == "Tutors" || maindata["category"] as? String == "Events"{
cell.title.text = maindata["title"] as? String
}
else if maindata["category"] as? String == "Sublet" || maindata["category"] as? String == "Rideshare"{
cell.title.text = maindata["location"] as? String
}
else{
cell.title.text = maindata["item"] as? String
}
if maindata["category"] as? String == "Sublet" || maindata["category"] as? String == "Rideshare"{
cell.location.text = ""
}
else{
cell.location.text = maindata["location"] as? String
}
cell.category.text = maindata["category"] as? String
cell.price.text = maindata["price"] as? String
return cell
}
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
}
}
So I have a globale variable called values which is a NSArray, and I want to set the value of this array to be the array that I retrieve from database. However, in function get(), the post request acts as another thread and I have to write self.values = array which doesn't change the value of my global variable.
I need that value to organize my tableview in the main array.
Basically, my question is how can I get the value from a closure and set it to a global variable.
Thank you! Let me know if you guys don't understand what I'm saying.

Answer 1

You need a completion handler in your func get() as you're doing the dataTaskWithRequest which is an Async call. Try this:
func get(finished: (isDone: Bool) -> ()){
//your code
data, response, error in
if error != nil {
finished(isDone: false)
print("error=\(error)")
return
}
print("response = \(response)")
let array = try! NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers) as! NSArray
self.values = array
}
}
task.resume()
finished(isDone: true)
}
And then in your viewDidLoad:
override func viewDidLoad() {
super.viewDidLoad()
get { success in
if success{
//reload your tableview here
}
}

Answer 2

The closure implicitly retains self, so you are actually modifying that property. But you need to refresh your tableView after the data is retrieved within the closure, either using reloadCellsAtIndexPath, insertCellsAtIndexPath, or reloadData. The latter is the simplest approach, but completely replaces the current state of the table.
Additionally, you are causing a retain cycle in your closure. You should pass in self as a weak or unowned property to let ARC do its job. For more information on that: http://krakendev.io/blog/weak-and-unowned-references-in-swift
Example:
func get(){
let request = NSMutableURLRequest(URL: NSURL(string: "http://www.percyteng.com/orbit/getAllpostsTest.php")!)
request.HTTPMethod = "POST"
let postString = "user=\("ios")"
request.HTTPBody = postString.dataUsingEncoding(NSUTF8StringEncoding)
let task = NSURLSession.sharedSession().dataTaskWithRequest(request) {
data, response, error in
if error != nil {
print("error=\(error)")
return
}
print("response = \(response)")
let array = try! NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers) as! NSArray
self.values = array
dispatch_async(dispatch_get_main_queue()) { [unowned self] in
self.tableView?.reloadData();
}
}
task.resume()
}