从一个闭包swift/firebase中修改一个变量-modifyingavariablefrominsideaclosureswift/firebase

In the function below, everything works except when I try to get the variable partnerName from point A to point B, i.e. moving the variable in an out of a closure. I am a novice coder so I am hoping that someone can help me discover how to solve this particular issue and point me to a place where I might be able to learn the basics of how to share variables between different parts of a function.

在下面的函数中,一切都有效,除非我尝试从A点到B点获取变量partnerName,即将变量移出闭包。我是一名新手编码器,所以我希望有人可以帮我发现如何解决这个特定问题并指出我可以学习如何在函数的不同部分之间共享变量的基础知识。

func getAllConversations(handler: @escaping (_ conversationsArray: [Conversation]) -> ()) {
        var partner = [""]
        var title: String = ""
        var partnerName = ""

        var cOnversationsArray= [Conversation]()
        REF_CONVERSATION.observeSingleEvent(of: .value) { (conversationSnapshot) in
            guard let cOnversationSnapshot= conversationSnapshot.children.allObjects as? [DataSnapshot] else { return}
            for conversation in conversationSnapshot {
                let memberArray = conversation.childSnapshot(forPath: "members").value as! [String]
                partner = memberArray.filter {$0 != (Auth.auth().currentUser?.uid)!}
                if memberArray.contains((Auth.auth().currentUser?.uid)!) {

                    let newPartner = (String(describing: partner))
                    title = newPartner.replacingOccurrences(of: "[\\[\\]\\^+<>\"]", with: "", options: .regularExpression, range: nil)

                        databaseRef.child("bodhi").child(title).observeSingleEvent(of: .value, with: { (snapshot) in

                            if let bodhiDict = snapshot.value as? [String: AnyObject]
                            {
                                //I realize that the variable is being wrongly redeclared here to make this run.
                                let partnerName = (bodhiDict["Name"] as! String)
                                    print ("partnerName returned from firebase: \(partnerName)")
                                // Point A: This prints "Sandy"
                            }
                        })

                    print ("partnerName: \(partnerName)")
                    // Point B: This prints nothing but if I add partnerName = "Sandy", then the function complete
                    title = partnerName
                    print ("new title: \(title)")
                    let cOnversation= Conversation(conversationTitle: title, key: conversation.key, conversationMembers: memberArray, conversationMemberCount: memberArray.count)
                    conversationsArray.append(conversation)
                }
            }
            handler(conversationsArray)
        }
    }

    func createGroup(withTitle title: String, andDescription description: String, forUserIds ids: [String], handler: @escaping (_ groupCreated: Bool) -> ()) {
        REF_GROUPS.childByAutoId().updateChildValues(["title": title, "description": description, "members": ids])
        //    need to add code here for slow internet: if successful connection true else error
        handler(true)
    }

    func getAllGroups(handler: @escaping (_ groupsArray: [Group]) -> ()) {
        var groupsArray = [Group]()
        REF_GROUPS.observeSingleEvent(of: .value) { (groupSnapshot) in
            guard let groupSnapshot = groupSnapshot.children.allObjects as? [DataSnapshot] else { return}
            for group in groupSnapshot {
                let memberArray = group.childSnapshot(forPath: "members").value as! [String]
                if memberArray.contains((Auth.auth().currentUser?.uid)!) {
                    let title = group.childSnapshot(forPath: "title").value as! String
                    let description = group.childSnapshot(forPath: "description").value as! String
                    let group = Group(title: title, description: description, key: group.key, members: memberArray, memberCount: memberArray.count)
                    groupsArray.append(group)
                }
            }
            handler(groupsArray)
        }
    }

}

1 个解决方案