記載してあるのに、Value of type ファイル名 has no member 関数名

Question

同じファイル内にある関数Aをself.関数Aで呼び出したい

エラーメッセージ

Value of type 'ChatController' has no member 'fetchMessage'

該当コード

        func observeMessages() {
            guard let currentUid = Auth.auth().currentUser?.uid else { return }
            guard let chatPartnerId = self.user?.uid else { return }

            USER_MESSAGES_REF.child(currentUid).child(chatPartnerId).observe(.childAdded) { (snapshot) in
                let messageId = snapshot.key
                self.fetchMessage(withMessageId: messageId)
//////////ここでValue of type 'ChatController' has no member 'fetchMessage'と警告される//////////
            }
        }

        func fetchMessage(withMessageId messageId: String) {
            MESSAGES_REF.child(messageId).observeSingleEvent(of: .value) { (snapshot) in
                guard let dictionary = snapshot.value as? Dictionary<String, AnyObject> else { return }
                let message = Message(dictionary: dictionary)
                self.messages.append(message)
            }
        }
}
}

該当ファイル全コード

import UIKit
import Firebase

private let reuseIdentifier = "ChatCell"

class ChatController: UICollectionViewController, UICollectionViewDelegateFlowLayout {

    // MARK: - Properties

    var user: User?
    var messages = [Message]()

    lazy var containerView: UIView =  {
        let containerView = UIView()
        containerView.frame = CGRect(x: 0, y: 0, width: 100, height: 55)


        containerView.addSubview(sendButton)
        sendButton.anchor(top: nil, left: nil, bottom: nil, right: containerView.rightAnchor, paddingTop: 0, paddingLeft: 0, paddingBottom: 0, paddingRight: 8, width: 50, height: 0)
        sendButton.centerYAnchor.constraint(equalTo: containerView.centerYAnchor).isActive = true

        containerView.addSubview(messageTextField)
        messageTextField.anchor(top: containerView.topAnchor, left: containerView.leftAnchor, bottom: containerView.bottomAnchor, right: sendButton.leftAnchor, paddingTop: 0, paddingLeft: 12, paddingBottom: 0, paddingRight: 0, width: 0, height: 0)



        let separatorView = UIView()
        separatorView.backgroundColor = .lightGray
        containerView.addSubview(separatorView)
        separatorView.anchor(top: containerView.topAnchor, left: containerView.leftAnchor, bottom: nil, right: containerView.rightAnchor, paddingTop: 0, paddingLeft: 0, paddingBottom: 0, paddingRight: 0, width: 0, height: 0.5)


        return containerView
    }()

    let messageTextField: UITextField = {
        let tf = UITextField()
        tf.placeholder = "Enter message.."
        return tf
    }()

    let sendButton: UIButton = {
        let button = UIButton(type: .system)
        button.setTitle("Send", for: .normal)
        button.titleLabel?.font = UIFont.boldSystemFont(ofSize: 14)
        button.addTarget(self, action: #selector(handleSend), for: .touchUpInside)
        return button
    }()

    // MARK: - Init

    override func viewDidLoad() {
        super.viewDidLoad()

        collectionView.backgroundColor = .white

        collectionView.register(ChatCell.self, forCellWithReuseIdentifier: reuseIdentifier)

        configureNavigationBar()

        observeMessages()
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        tabBarController?.tabBar.isHidden = true
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        tabBarController?.tabBar.isHidden = false
    }

    override var inputAccessoryView: UIView? {

        get  {
            return containerView
        }
    }

    override var canBecomeFirstResponder: Bool{
        return true
    }


    // MARK: - UICollectionView

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        return CGSize(width: view.frame.width / 2, height: 50)
    }

    override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return messages.count
    }

    override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifier, for: indexPath) as! ChatCell

        cell.backgroundColor = .red

        return cell
    }

    // MARK: - Handlers

    @objc func handleSend() {
        uploadMessagesToServer()
        messageTextField.text = nil
    }

    @objc func handleInfoTapped() {
        print("Handle info tapped")
    }

    func configureNavigationBar() {
        guard let user = self.user else { return }

        navigationItem.title = user.username

        let infoButton = UIButton(type: .infoLight)
        infoButton.tintColor = .black
        infoButton.addTarget(self, action: #selector(handleInfoTapped), for: .touchUpInside)

        let infoBarButtonItem = UIBarButtonItem(customView: infoButton)

        navigationItem.rightBarButtonItem = infoBarButtonItem
    }

    // MARK: - API
    

    func uploadMessagesToServer() {

        guard let messageText = messageTextField.text else { return }
        guard let currentUid = Auth.auth().currentUser?.uid else { return }
        guard let user = self.user else { return }
        let creationDate = Int(NSDate().timeIntervalSince1970)

        // UPDATE: - Safely unwrapped uid to work with Firebase 5
        guard let uid = user.uid else { return }

        var values: [String: AnyObject] = ["toId": user.uid as AnyObject, "fromId": currentUid as AnyObject, "creationDate": creationDate as AnyObject, "read": false as AnyObject]


        let messageRef = MESSAGES_REF.childByAutoId()

        // UPDATE: - Safely unwrapped messageKey to work with Firebase 5
        guard let messageKey = messageRef.key else { return }

        messageRef.updateChildValues(values) { (err, ref) in
            USER_MESSAGES_REF.child(currentUid).child(uid).updateChildValues([messageKey: 1])
            USER_MESSAGES_REF.child(uid).child(currentUid).updateChildValues([messageKey: 1])
        }

        func observeMessages() {
            guard let currentUid = Auth.auth().currentUser?.uid else { return }
            guard let chatPartnerId = self.user?.uid else { return }

            USER_MESSAGES_REF.child(currentUid).child(chatPartnerId).observe(.childAdded) { (snapshot) in
                let messageId = snapshot.key
                self.fetchMessage(withMessageId: messageId)
            }
        }

        func fetchMessage(withMessageId messageId: String) {
            MESSAGES_REF.child(messageId).observeSingleEvent(of: .value) { (snapshot) in
                guard let dictionary = snapshot.value as? Dictionary<String, AnyObject> else { return }
                let message = Message(dictionary: dictionary)
                self.messages.append(message)
            }
        }
}
}

やったこと
この記事を参考に変数などの書き直しをしました。

Answer 1

// 移動1
    func observeMessages() {
        guard let currentUid = Auth.auth().currentUser?.uid else { return }
        guard let chatPartnerId = self.user?.uid else { return }

        USER_MESSAGES_REF.child(currentUid).child(chatPartnerId).observe(.childAdded) { (snapshot) in
            let messageId = snapshot.key

            self.fetchMessage(withMessageId: messageId)
        }
    }

    // 移動2
    func fetchMessage(withMessageId messageId: String) {
        MESSAGES_REF.child(messageId).observeSingleEvent(of: .value) { (snapshot) in
            guard let dictionary = snapshot.value as? Dictionary<String, AnyObject> else { return }

            let message = Message(dictionary: dictionary)

            self.messages.append(message)

            self.collectionView.reloadData()
        }
    }

    // MARK: - API
    

    func uploadMessagesToServer() {

        guard let messageText = messageTextField.text else { return }
        guard let currentUid = Auth.auth().currentUser?.uid else { return }
        guard let user = self.user else { return }
        let creationDate = Int(NSDate().timeIntervalSince1970)

        // UPDATE: - Safely unwrapped uid to work with Firebase 5
        guard let uid = user.uid else { return }

        var values: [String: AnyObject] = ["toId": user.uid as AnyObject, "fromId": currentUid as AnyObject, "creationDate": creationDate as AnyObject, "read": false as AnyObject]


        let messageRef = MESSAGES_REF.childByAutoId()

        // UPDATE: - Safely unwrapped messageKey to work with Firebase 5
        guard let messageKey = messageRef.key else { return }

        messageRef.updateChildValues(values) { (err, ref) in
            USER_MESSAGES_REF.child(currentUid).child(uid).updateChildValues([messageKey: 1])
            USER_MESSAGES_REF.child(uid).child(currentUid).updateChildValues([messageKey: 1])
        }

// 移動1

        // 移動2


}
}

これでエラーは解消されました！