Swift reload collection view not working

I am new to swift. I follow some tutorial to develop social application like twitter application to follow the tutorial. I start implement to follow button functions. its call the the another API call but same response come with minor modification(e.g - number of follower property increase by one). call also perfectly working. but collection view did not reload.my code is.

ViewConroller

import LBTAComponents
import TRON
import SwiftyJSON

class HomeDatasourceController: DatasourceController

let errorMessageLabel: UILabel =
let label = UILabel()
label.text = "Apologies something went wrong. Please try again later..."
label.textAlignment = .center
label.numberOfLines = 0
label.isHidden = true
return label
()

override func willTransition(to newCollection: UITraitCollection, with coordinator: UIViewControllerTransitionCoordinator)
collectionViewLayout.invalidateLayout()


func follow()
print("inside controller")
Service.sharedInstance.fetchfollowHomeFeed (homeDatasource, err) in
if let err = err
self.errorMessageLabel.isHidden = false

if let apiError = err as? APIError<Service.JSONError>

if apiError.response?.statusCode != 200
self.errorMessageLabel.text = "Status code was not 200"



return

self.datasource = homeDatasource
self.collectionView?.reloadData()



override func viewDidLoad()
super.viewDidLoad()

view.addSubview(errorMessageLabel)
errorMessageLabel.fillSuperview() //LBTA method call

collectionView?.backgroundColor = UIColor(r: 232, g: 236, b: 241)

setupNavigationBarItems()

Service.sharedInstance.fetchHomeFeed (homeDatasource, err) in
if let err = err
self.errorMessageLabel.isHidden = false

if let apiError = err as? APIError<Service.JSONError>

if apiError.response?.statusCode != 200
self.errorMessageLabel.text = "Status code was not 200"



return


self.datasource = homeDatasource



func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat
return 0


override func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize

//first section of users
if indexPath.section == 0
guard let user = self.datasource?.item(indexPath) as? User else return .zero

let estimatedHeight = estimatedHeightForText(user.bioText)
return CGSize(width: view.frame.width, height: estimatedHeight + 66)
else if indexPath.section == 1
//our tweets size estimation

guard let tweet = datasource?.item(indexPath) as? Tweet else return .zero

let estimatedHeight = estimatedHeightForText(tweet.message)

return CGSize(width: view.frame.width, height: estimatedHeight + 74)



return CGSize(width: view.frame.width, height: 200)


private func estimatedHeightForText(_ text: String) -> CGFloat
let approximateWidthOfBioTextView = view.frame.width - 12 - 50 - 12 - 2
let size = CGSize(width: approximateWidthOfBioTextView, height: 1000)
let attributes = [NSFontAttributeName: UIFont.systemFont(ofSize: 15)]

let estimatedFrame = NSString(string: text).boundingRect(with: size, options: .usesLineFragmentOrigin, attributes: attributes, context: nil)

return estimatedFrame.height


func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize
if section == 1
return .zero

return CGSize(width: view.frame.width, height: 50)


func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForFooterInSection section: Int) -> CGSize
if section == 1
return .zero

return CGSize(width: view.frame.width, height: 64)





DataSource

import LBTAComponents
import TRON
import SwiftyJSON

extension Collection where Iterator.Element == JSON
func decode<T: JSONDecodable>() throws -> [T]
return try maptry T(json: $0)



class HomeDatasource: Datasource, JSONDecodable

let users: [User]

required init(json: JSON) throws
guard let usersJsonArray = json["users"].array, let tweetsJsonArray = json["tweets"].array else
throw NSError(domain: "com.letsbuildthatapp", code: 1, userInfo: [NSLocalizedDescriptionKey: "Parsing JSON was not valid."])


// self.users = usersJsonArray.mapUser(json: $0)
// self.tweets = tweetsJsonArray.mapTweet(json: $0)

self.users = try usersJsonArray.decode()
self.tweets = try tweetsJsonArray.decode()



let tweets: [Tweet]

override func footerClasses() -> [DatasourceCell.Type]?
return [UserFooter.self]


override func headerClasses() -> [DatasourceCell.Type]?
return [UserHeader.self]


override func cellClasses() -> [DatasourceCell.Type]
return [UserCell.self, TweetCell.self]


override func item(_ indexPath: IndexPath) -> Any?
if indexPath.section == 1
return tweets[indexPath.item]

return users[indexPath.item]


override func numberOfSections() -> Int
return 2


override func numberOfItems(_ section: Int) -> Int
if section == 1
return tweets.count

return users.count





DataCell

import LBTAComponents

class UserCell: DatasourceCell

override var datasourceItem: Any?
didSet
guard let user = datasourceItem as? User else return
followButton.addTarget(self, action: #selector(follow), for: .touchUpInside)
nameLabel.text = user.name
usernameLabel.text = user.username
bioTextView.text = user.bioText

profileImageView.loadImage(urlString: user.profileImageUrl)



let profileImageView: CachedImageView =
let imageView = CachedImageView()
imageView.image = #imageLiteral(resourceName: "profile_image")
imageView.layer.cornerRadius = 5
imageView.clipsToBounds = true
return imageView
()

let nameLabel: UILabel =
let label = UILabel()
label.text = "Brian Voong"
label.font = UIFont.boldSystemFont(ofSize: 16)
return label
()

let usernameLabel: UILabel =
let label = UILabel()
label.text = "@buildthatapp"
label.font = UIFont.systemFont(ofSize: 14)
label.textColor = UIColor(r: 130, g: 130, b: 130)
return label
()

let bioTextView: UITextView =
let textView = UITextView()
textView.text = "iPhone, iPad, iOS Programming Community. Join us to learn Swift, Objective-C and build iOS apps!"
textView.font = UIFont.systemFont(ofSize: 15)
textView.backgroundColor = .clear
return textView
()

let followButton: UIButton =
let button = UIButton()
button.layer.cornerRadius = 5
button.layer.borderColor = twitterBlue.cgColor
button.layer.borderWidth = 1
button.setTitle("Follow", for: .normal)
button.titleLabel?.font = UIFont.boldSystemFont(ofSize: 14)
button.setTitleColor(twitterBlue, for: .normal)
button.setImage(#imageLiteral(resourceName: "follow"), for: .normal)
button.imageView?.contentMode = .scaleAspectFit
button.imageEdgeInsets = UIEdgeInsets(top: 0, left: -8, bottom: 0, right: 0)
// button.titleEdgeInsets = UIEdgeInsets
return button
()
func follow()
print("inside source")
var link = HomeDatasourceController()
link.follow()

override func setupViews()
super.setupViews()

backgroundColor = .white

separatorLineView.isHidden = false
separatorLineView.backgroundColor = UIColor(r: 230, g: 230, b: 230)

addSubview(profileImageView)
addSubview(nameLabel)
addSubview(usernameLabel)
addSubview(bioTextView)
addSubview(followButton)

profileImageView.anchor(self.topAnchor, left: self.leftAnchor, bottom: nil, right: nil, topConstant: 12, leftConstant: 12, bottomConstant: 0, rightConstant: 0, widthConstant: 50, heightConstant: 50)

nameLabel.anchor(profileImageView.topAnchor, left: profileImageView.rightAnchor, bottom: nil, right: followButton.leftAnchor, topConstant: 0, leftConstant: 8, bottomConstant: 0, rightConstant: 12, widthConstant: 0, heightConstant: 20)

usernameLabel.anchor(nameLabel.bottomAnchor, left: nameLabel.leftAnchor, bottom: nil, right: nameLabel.rightAnchor, topConstant: 0, leftConstant: 0, bottomConstant: 0, rightConstant: 0, widthConstant: 0, heightConstant: 20)

bioTextView.anchor(usernameLabel.bottomAnchor, left: usernameLabel.leftAnchor, bottom: self.bottomAnchor, right: self.rightAnchor, topConstant: -4, leftConstant: -4, bottomConstant: 0, rightConstant: 0, widthConstant: 0, heightConstant: 0)

followButton.anchor(topAnchor, left: nil, bottom: nil, right: self.rightAnchor, topConstant: 12, leftConstant: 0, bottomConstant: 0, rightConstant: 12, widthConstant: 120, heightConstant: 34)




It using LBTA components.i tried self.collectionView?.reloadData() but its not reloaded. Please help me to fix this problem.download my full source code here Please help me

self.collectionView?.reloadData()

self.datasource = homeDatasource

1 Answer
1

I have seen your project and found issue which you did.
In class UserCell.swift, you should use next code:

func follow()
print("inside source")
guard let link = controller as? HomeDatasourceController else return
link.follow()



Explain issue

This's your code that was in project

func follow()
print("inside source")
var link = HomeDatasourceController() // in this place you create a new local instance of class 'HomeDatasourceController'
link.follow()



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