TableView Not Updating After Item Is Added To Array - swift

Question

I am building an app that uses the Twitter API to post to a user's Twitter and load those tweets in a TableView. The table loads correctly when the app first launches. However, after composing and posting a Tweet (confirmed that the Tweet is posted and in the array) the table view is still displaying the same tweets prior without the newly created one. I thought it might have something to do with the asynchronous code so I implemented the DispatchQueue in the refreshData() function. The table view is still not loading the most recently added tweet. How can I change the refreshData() function so that the table updates when Tweet is posted successfully?
import UIKit
import OAuthSwift
class FeedViewController: UIViewController, UITableViewDelegate, UITableViewDataSource, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
#IBOutlet weak var tableView: UITableView!
#IBOutlet weak var tweetText: UITextField!
var user: User!
var tweets = [Tweet]()
override func viewDidLoad() {
super.viewDidLoad()
tableView.delegate = self
tableView.dataSource = self
self.tableView.rowHeight = 200
let consumerSecret = user.consumerSecret
let consumerKey = user.consumerKey
let oAuthToken = user.oAuthToken
let oAuthSecret = user.oAuthSecret
let oauthswift = user.oauthswift
let screen_name = user.screen_name
print("Feed Consumer Secret: \(consumerSecret)")
print("Feed Consumer Key: \(consumerKey)")
print("Feed Auth Token: \(oAuthToken)")
print("Feed Auth Secret: \(oAuthSecret)")
print("Screen Name: \(screen_name)")
loadFeed(oauthswift: oauthswift)
// Do any additional setup after loading the view.
}
#IBAction func postButtonPushed(_ sender: Any) {
let oauthswift = user.oauthswift
let url = "https://api.twitter.com/1.1/statuses/update.json?status="
let tweet_url = tweetText.text
let encoded_tweet = tweet_url?.addingPercentEncoding(withAllowedCharacters: CharacterSet.urlHostAllowed)
let new_url = url + encoded_tweet!
let _ = oauthswift.client.post(
new_url, parameters: [:],
success: { response in
let dataString = response.string!
let jsonDict = try? response.jsonObject()
let jsonDict2 = jsonDict as! Dictionary<String,Any>
let tweetText2 = jsonDict2["text"]!
let jsonDict4 = jsonDict2["user"] as! Dictionary<String,Any>
let username = jsonDict4["screen_name"]!
let newTweet = Tweet(tweetText: tweetText2 as! String, username: username as! String)
self.tweets.append(newTweet)
print(username)
//print(dataString)
self.loadFeed(oauthswift: oauthswift)
self.tweetText.text = ""
},
failure: { error in
print(error)
}
)
}
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let tweet = tweets[indexPath.row]
if let cell = tableView.dequeueReusableCell(withIdentifier: "PostCell") as? PostCell {
cell.configureCell(tweet: tweet)
return cell
} else {
return PostCell()
}
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return tweets.count
}
func loadFeed(oauthswift: OAuth1Swift){
print("LOAD FEED")
let _ = oauthswift.client.get(
"https://api.twitter.com/1.1/statuses/user_timeline.json?screen_name=\(user.screen_name)", parameters: [:],
success: { response in
let jsonDict = try? response.jsonObject()
let jsonDict2 = jsonDict as! Array<Dictionary<String,Any>>
let arrayCount = jsonDict2.count
for index in 0...arrayCount - 1 {
let jsonDict4 = jsonDict2[index]["user"] as! Dictionary<String,Any>
let tweetText = jsonDict2[index]["text"]!
let username = jsonDict4["screen_name"]!
let newTweet = Tweet(tweetText: tweetText as! String, username: username as! String)
self.tweets.append(newTweet)
print(tweetText)
}
self.refreshData()
}, failure: { error in
print(error)
}
)
}
func refreshData() {
DispatchQueue.main.async{
self.tableView.reloadData()
}
}
}
PostCell.swift
import UIKit
class PostCell: UITableViewCell {
#IBOutlet weak var userLabel: UILabel!
#IBOutlet weak var tweetLabel: UILabel!
var tweet: Tweet!
func configureCell(tweet: Tweet) {
self.userLabel.text = "#\(tweet.username)"
self.tweetLabel.text = tweet.tweetText
print(tweet.tweetText)
}
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
}

Answer 1

Since you are sure that Twitter accepted the post and you appended the new Tweet to the data source there is no need for a full reloadData. You can display just the new row in the table.
In FeedViewController, in method postButtonPushed, inside the oauthswift.client.post's success clousure right after this line self.tweets.append(newTweet) add this:
DispatchQueue.main.async {
self.tableView.beginUpdates()
self.tableView.insertRows(at: [IndexPath(item: self.tweets.count-1, section: 0)],
with: .automatic)
self.tableView.endUpdates()
}