Table View not updating with data fetched by HTTP Request - ios

Question

I'm trying to populate a table view with data fetched from a http request (JSON) but it's not working. If I populate the Table View with static data everything works fine.. code snippet:
import UIKit
import Alamofire
//import SwiftyJSON
class ViewControllerNews : UITableViewController{
#IBOutlet var table: UITableView!
var posts = [FacebookPost]()
override func viewDidLoad() {
pullFacebookNews()
//loadSampleNews()
super.viewDidLoad()
}
func pullFacebookNews() -> Void {
let params = ["limit":"100", "access_token": myaccesstoken]
Alamofire.request( "https://graph.facebook.com/<page-id>/posts", parameters: params).responseJSON{ response in
if let responsejson = response.result.value {
let JSON = responsejson as! NSDictionary
let itemsArray: NSArray? = JSON.object(forKey: "data") as? NSArray
if(itemsArray != nil) {
for item in itemsArray! {
let thisitem = item as! NSDictionary
print(thisitem.object(forKey: "message") as? String)
print(thisitem.object(forKey:"created_time") as? String)
let title1 = thisitem.object(forKey: "message") as? String
let value1=thisitem.object(forKey:"created_time") as? String
if(title1 != nil && value1 != nil) {
let news = FacebookPost(title: title1!, value: value1!)
self.posts.append(news)
}
}}
}
}
do_table_refresh()
}
func do_table_refresh() {
DispatchQueue.global(qos: .background).async {
DispatchQueue.main.async {
self.table.reloadData()
}
}
}
func loadSampleNews() {
let news1 = FacebookPost(title: "ich bin ein datum", value: "Ich bin eine news")
let news2 = FacebookPost(title: "ich bin ein datum2", value: "Ich bin eine news2")
let news3 = FacebookPost(title: "ich bin ein datum3", value: "Ich bin eine news3")
posts += [news1, news2, news3]
}
override func numberOfSections(in: UITableView) -> Int {
return 1
}
override func tableView(_: UITableView, numberOfRowsInSection section: Int) -> Int {
return posts.count
}
override func tableView(_: UITableView, cellForRowAt: IndexPath) -> UITableViewCell {
let cellIdentifier = "NewsTableViewCell"
let cell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier, for: cellForRowAt as IndexPath) as! NewsTableViewCell
let news = posts[cellForRowAt.row]
cell.date.text = news.title
cell.news_text.text = news.value
return cell
}
}
The loadSampeNews() works perfectly, but pullFacebookNews() does not populate the table. While debugging the array is filled..

Answer 1

If you set breakpoints, you will see that do_table_refresh() gets called before you hit if let responsejson = response.result.value. This is because the Alamofire call has a completion handler. You have to wait until the internet call is complete before you call do_table_refresh().
So you essentially just have to move do_table_refresh() if all of your data is loading correctly like you say it is.
func pullFacebookNews() -> Void {
let params = ["limit":"100", "access_token": myaccesstoken]
Alamofire.request( "https://graph.facebook.com/<page-id>/posts", parameters: params).responseJSON{ response in
if let responsejson = response.result.value {
let JSON = responsejson as! NSDictionary
let itemsArray: NSArray? = JSON.object(forKey: "data") as? NSArray
if(itemsArray != nil) {
for item in itemsArray! {
let thisitem = item as! NSDictionary
print(thisitem.object(forKey: "message") as? String)
print(thisitem.object(forKey:"created_time") as? String)
let title1 = thisitem.object(forKey: "message") as? String
let value1=thisitem.object(forKey:"created_time") as? String
if(title1 != nil && value1 != nil) {
let news = FacebookPost(title: title1!, value: value1!)
self.posts.append(news)
}
}
}
self.do_table_refresh()
}
}
}
Additionally, don't name your methods with that syntax. It is not best practice. Should be doTableRefresh() or something.