UITableView creates Blank cells and not any values from JSON - ios

Question

I am trying to load the values from the JSON to the tableview. Here is my code, I dont know what am I missing? It shows me a list of blank cells but not any values.
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
var tableView: UITableView!
let baseURL = “<url>”
var items = [UserObject]()
override func viewDidLoad() {
super.viewDidLoad()
let frame:CGRect = CGRect(x: 0, y: 100, width: self.view.frame.width, height: self.view.frame.height-100)
self.tableView = UITableView(frame: frame)
self.tableView.dataSource = self
self.tableView.delegate = self
self.view.addSubview(self.tableView)
getJSON()
dispatch_async(dispatch_get_main_queue(),{
self.tableView.reloadData()
})
}
//5 rows
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
print("count /(self.items.count)")
return self.items.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell = tableView.dequeueReusableCellWithIdentifier("CELL")
if cell == nil {
cell = UITableViewCell(style: UITableViewCellStyle.Value1, reuseIdentifier: "CELL")
}
let user = self.items[indexPath.row]
print(self.items)
cell!.textLabel?.text = user.name
return cell!
}
func getJSON() {
let url = NSURL(string: baseURL)
print(url)
let request = NSURLRequest(URL: url!)
let session = NSURLSession(configuration: NSURLSessionConfiguration.defaultSessionConfiguration())
let task = session.dataTaskWithRequest(request) { (data, response, error) -> Void in
if error == nil {
let swiftyJSON = JSON(data: data!)
let results = swiftyJSON.arrayValue
for entry in results {
self.items.append(UserObject(json: entry))
}
} else {
print("error \(error)")
}
}
task.resume()
}
}
Please note, print("count /(self.items.count)") returns 4 which is correct but
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
//function does not show any print statements.
}

Answer 1

You should call the tableview's reloadData func after your async request is finished.
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
var tableView: UITableView!
let baseURL = “<url>”
var items = [UserObject]()
override func viewDidLoad() {
super.viewDidLoad()
let frame:CGRect = CGRect(x: 0, y: 100, width: self.view.frame.width, height: self.view.frame.height-100)
self.tableView = UITableView(frame: frame)
self.tableView.dataSource = self
self.tableView.delegate = self
self.view.addSubview(self.tableView)
getJSON()
}
//5 rows
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
print("count /(self.items.count)")
return self.items.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell = tableView.dequeueReusableCellWithIdentifier("CELL")
if cell == nil {
cell = UITableViewCell(style: UITableViewCellStyle.Value1, reuseIdentifier: "CELL")
}
let user = self.items[indexPath.row]
print(self.items)
cell!.textLabel?.text = user.name
cell!.detailTextLabel?.text = user.date // UPDATE
return cell!
}
func getJSON() {
let url = NSURL(string: baseURL)
print(url)
let request = NSURLRequest(URL: url!)
let session = NSURLSession(configuration: NSURLSessionConfiguration.defaultSessionConfiguration())
let task = session.dataTaskWithRequest(request) { (data, response, error) -> Void in
if error == nil {
let swiftyJSON = JSON(data: data!)
let results = swiftyJSON.arrayValue
for entry in results {
self.items.append(UserObject(json: entry))
}
dispatch_async(dispatch_get_main_queue(),{
self.tableView.reloadData()
})
} else {
print("error \(error)")
}
}
task.resume()
}
}

Answer 2

Your Get json function should be like,
func getJSON() {
let url = NSURL(string: baseURL)
print(url)
let request = NSURLRequest(URL: url!)
let session = NSURLSession(configuration: NSURLSessionConfiguration.defaultSessionConfiguration())
let task = session.dataTaskWithRequest(request) { (data, response, error) -> Void in
if error == nil {
let swiftyJSON = JSON(data: data!)
let results = swiftyJSON.arrayValue
for entry in results {
self.items.append(UserObject(json: entry))
}
dispatch_async(dispatch_get_main_queue(),{
self.tableView.reloadData()
})
} else {
print("error \(error)")
}
}
task.resume()
}
and remove
dispatch_async(dispatch_get_main_queue(),{
self.tableView.reloadData()
})
from view didload. I have just put code of reloading table view in completion handler of web service call.