如何使用Firestore数据库在swift中为tableview中的项目列表设置后置键？

Question

Post模型Swift文件

import Foundation
import Firebase
import FirebaseFirestore

protocol DocumentSerializable  {
    init?(dictionary:[String:Any])
}

struct Post {
   // var name:String
   // var content:String
    //var timeStamp:Date
     var username: String!
     var postTitle: String!
    // var postKey:  String!
     var postcategory:  String!
     var postContent:  String!

    //private var _postRef: DocumentReference!

    var dictionary:[String:Any] {
        return [
            "username": username,
            //"profile_pic":profile_pic,
            "postTitle":postTitle,
            "postcategory":postcategory,
            "postContent":postContent
          //  "postKey":postKey
        ]
    }
}

extension Post : DocumentSerializable {
    init?(dictionary: [String : Any]) {
        guard  let username = dictionary["username"] as? String,
           // let profile_pic = dictionary["profile_pic"] as? String,
            let postTitle = dictionary["postTitle"] as? String,
            let postcategory = dictionary["postcategory"] as? String,
            let postContent = dictionary["postContent"] as? String   else { return nil }

          //  let postKey = dictionary["postKey"] as? String

        self.init(username: username, postTitle: postTitle, postcategory: postcategory, postContent: postContent )
    }
}

用于在tableview中登记帖子的ViewController类

import Foundation
import UIKit
import Firebase

class HomeViewController:UIViewController, UITableViewDelegate, UITableViewDataSource {

    var tableView:UITableView!

    var posts = [Post]()
    var db: Firestore!        

    private var documents: [DocumentSnapshot] = []
    //public var posts: [Post] = []
    private var listener : ListenerRegistration!    

    override func viewDidLoad() {
        super.viewDidLoad()

        db = Firestore.firestore()

        self.navigationController?.navigationBar.isTranslucent = false
        tableView = UITableView(frame: view.bounds, style: .plain)

        let cellNib = UINib(nibName: "PostTableViewCell", bundle: nil)
        tableView.register(cellNib, forCellReuseIdentifier: "postCell")
        tableView.backgroundColor = UIColor(white: 0.90,alpha:1.0)
        view.addSubview(tableView)

        var layoutGuide:UILayoutGuide!

        if #available(iOS 11.0, *) {
            layoutGuide = view.safeAreaLayoutGuide
        } else {
            // Fallback on earlier versions
            layoutGuide = view.layoutMarginsGuide
        }

        tableView.leadingAnchor.constraint(equalTo: layoutGuide.leadingAnchor).isActive = true
        tableView.topAnchor.constraint(equalTo: layoutGuide.topAnchor).isActive = true
        tableView.trailingAnchor.constraint(equalTo: layoutGuide.trailingAnchor).isActive = true
        tableView.bottomAnchor.constraint(equalTo: layoutGuide.bottomAnchor).isActive = true

        tableView.delegate = self
        tableView.dataSource = self
        tableView.reloadData()

        retrieveAllPosts()            
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    @IBAction func handleLogout(_ sender:Any) {
        try! Auth.auth().signOut()
        self.dismiss(animated: false, completion: nil)
    }

    func retrieveAllPosts(){
        let postsRef = Firestore.firestore().collection("posts").limit(to: 50)

        postsRef.getDocuments() { (querySnapshot, err) in
            if let err = err {
                print("Error getting documents: \(err)")
            } else {
                for document in querySnapshot!.documents {
                    print("\(document.documentID) => \(document.data())")

                    self.posts = querySnapshot!.documents.flatMap({Post(dictionary: $0.data())})
                    DispatchQueue.main.async {
                        self.tableView.reloadData()
                    }                                   
                }
            }
        }

    }
    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return posts.count
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "postCell", for: indexPath) as! PostTableViewCell
        cell.set(post: posts[indexPath.row])
        return cell
    }
}

Answer 1

它将不是一个简单的帖子键，你将需要创建名为“评论”的帖子喜欢子文档，在该列表中，你将需要添加评论内容，用户，图瑟，帖子等。只添加postKey不会解决您的问题

下面是一个简单的例子

let postId = "45f4854fjrh4"   // documentId of post
    let commentData = [commentContent:"this is comment", "commenterId":"242343f3ffd3", "postId": postId, "commentName":"\(youProfileName)", "onPost":"45454252342","postOwnerId":"34343434543"

注：您可以根据需要设置以下或以上数据

Firestore.firestore().collection("posts/\(postId)/Comments").addDocument(commentData)