访问 childAutoID 以更新 Firebase 中的选定子值

Question

为了填充我的 tableView，我将项目（从结构创建）附加到本地数组：

func loadList() {
        var newAnnotations: [AnnotationListItem] = []
    if let uid = Auth.auth().currentUser?.uid {
        uidRef.child(uid).child("annotations").queryOrderedByKey().observeSingleEvent(of: .value, with: {snapshot in

            for item in snapshot.children {
                let annotationItem = AnnotationListItem(snapshot: item as! DataSnapshot)
                newAnnotations.append(annotationItem)
            }
            annotationList = newAnnotations
            self.tableView.reloadSections([0], with: .fade)
        })
    }
}

当我点击一个特定的行时，我被带到一个DetailViewController，它只是一个大的UITextView（命名注释）。显示的UITextView.text 基于选定的indexPath.row，并且从数组中检索“notes”值。现在用户可以输入一些文本，完成后，textViewDidEndEditing 函数被调用：

func textViewDidEndEditing(_ textView: UITextView) {
    notes.resignFirstResponder()
    navigationItem.rightBarButtonItem = nil

    let newNotes = self.notes.text
    print(newNotes!)
}

现在我想updateChildValues 到 newNotes 到我的 JSON 中的子节点“notes”：

"users" : {
  "gI5dKGOX7NZ5UBqeTdtu30Ze9wG3" : {
    "annotations" : {
      "-KuWIRBARv7osWr3XDZz" : {
        "annotationSubtitle" : "1 Cupertino CA",
        "annotationTitle" : "Apple Infinite Loop",
        "notes" : "Does it work?!",
    }

如何访问选定的autoID，以便更新特定的notes 节点。到目前为止，我拥有的最好的是：

guard let uid = Auth.auth().currentUser?.uid else { return }
    uidRef.child(uid).child("annotations").(somehow access the specific childID).updateChildValues(["notes": newNotes])

任何帮助将不胜感激。在此先感谢

更新

annotationListItem 结构已创建：

struct AnnotationListItem {

let key: String?
var annotationTitle: String?
let annotationSubtitle: String?
let notes: String?
let ref: DatabaseReference?

init(key: String = "", annotationTitle: String, annotationSubtitle: String, notes: String) {
    self.key = key
    self.annotationTitle = annotationTitle
    self.annotationSubtitle = annotationSubtitle
    self.notes = notes
    self.ref = nil
}

init(snapshot: DataSnapshot) {
    key = snapshot.key
    let snapshotValue = snapshot.value as! [String: AnyObject]
    annotationTitle = snapshotValue["annotationTitle"] as? String
    annotationSubtitle = snapshotValue["annotationSubtitle"] as? String
    notes = snapshotValue["notes"] as? String
    ref = snapshot.ref
}

init(Dictionary: [String: AnyObject]) {
    self.key = Dictionary["key"] as? String
    self.annotationTitle = Dictionary["annotationTitle"] as? String
    self.annotationSubtitle = Dictionary["annotationSubtitle"] as? String
    self.notes = Dictionary["notes"] as? String
    self.ref = nil
}

func toAnyObject() -> Any {
    return [
        "annotationTitle": annotationTitle as Any,
        "annotationSubtitle": annotationSubtitle as Any,
        "notes": notes as Any
    ]
}
}

更新

annotationListItem 是这样创建并存储在 Firebase 中的：

// Using the current user’s data, create a new AnnotationListItem that is not completed by default
    let uid = Auth.auth().currentUser?.uid
    guard let email = Auth.auth().currentUser?.email else { return }
    let title = placemark.name
    let subtitle = annotation.subtitle
    let notes = ""

    // declare variables
    let annotationListItem = AnnotationListItem(
        annotationTitle: title!,
        annotationSubtitle: subtitle!,
        notes: notes)

    // Add the annotation under their UID
    let userAnnotationItemRef = uidRef.child(uid!).child("annotations").childByAutoId()
    userAnnotationItemRef.setValue(annotationListItem.toAnyObject())

Answer 1

我认为您只需要这样做：（因为您已将注释声明为全局）

 guard let uid = Auth.auth().currentUser?.uid else { return } 
uidRef.child(uid).child("annotations").(note.key).updateChildValues(["notes": newNotes])

在你更改注释的方法内

Answer 2

如果我没记错的话，你是在创建一个自定义对象的数组吗？

var newAnnotations: [AnnotationListItem] = []

您可以执行以下操作：var newAnnotations: [(key: String, value: [String : Any])] = []（Any 仅当您将拥有 Strings、Integers 等时。如果它只是 String，则将其指定为 String .

访问密钥将是：newAnnotations[indexPath.row].key 在您的 cellForRowAtIndex 或您的 tableView 中。访问值将是：newAnnotations[indexPath.row].value["NAME"]。

您可以拥有一个单独的数组来保存密钥，然后将其与您的人口同时追加：

for item in snapshot.children {
      guard let itemSnapshot = task as? FDataSnapshot else {
           continue
      }
      let id = task.key //This is the ID
      let annotationItem = AnnotationListItem(snapshot: item as! DataSnapshot)
      newAnnotations.append(annotationItem)
}

您可以做的另一件事是在您的 firebase 调用中再上一层：

if let uid = Auth.auth().currentUser?.uid {
        uidRef.child(uid).child("annotations").observeSingleEvent(of: .value, with: {snapshot in
            if snapshot is NSNull{
                //Handles error
            } else{
                if let value = snapshot.value as? NSDictionary{ //(or [String: String]
                    //set localDictionary equal to value
                }
            }
            self.tableView.reloadSections([0], with: .fade)
        })
    }

然后当你选择一行时： let selectedItem = localDictionary.allKeys[indexPath.row] as! String //这是你传递给viewController的ID。