将自定义对象与自定义对象数组存储在Firebase中:Swift [英] Storing custom objects with array of custom objects in Firebase: Swift

问题描述

如何使用Swift在Firebase Realtime数据库中实现此设置:

How would I achieve this setup in Firebase Realtime Database with Swift:

数据库层次结构

当前，我通过将较大的元素(具有属性familyKey，geofences和phoneNumbers)存储为自定义对象来实现此目的.此外，geofences属性本身是自定义对象的数组.我得到了NSException以描述的方式执行此操作.我还能怎么做呢?

Currently, I am doing this by storing the larger element (with properties familyKey, geofences, and phoneNumbers) as a custom object. Also, the geofences property itself is an array of custom objects. I get an NSException doing this in the described fashion. How else would I go about doing this?

    var tempGeofences = [GeofenceData]()
    tempGeofences.append(GeofenceData(name: "Hello WOrld", latitude: 0, longitude: 0, radius: 1000))

    let familyKey:String = String(Int.random(in: 1000...99999))
    let uid:String = Auth.auth().currentUser!.uid
    let phoneNumber = "1111111111"
    let parent = Parent(phoneNumber: phoneNumber, familyKey: familyKey, geofences: tempGeofences)

    databaseRef.child(uid).setValue(parent)

在此行上引发了NSException:

The NSException is thrown on this line:

databaseRef.child(uid).setValue(parent)

父类:

import Foundation

public class Parent {
var phoneNumber: String?
var familyKey: String?
var geofences: [GeofenceData]?

init() {
    self.phoneNumber = ""
    self.familyKey = ""
    self.geofences = nil
}

init(phoneNumber: String?, familyKey: String?, geofences:[GeofenceData]) {
    self.phoneNumber = phoneNumber
    self.familyKey = familyKey
    self.geofences = geofences
}

public func getPhoneNumber() -> String {
    return phoneNumber!
}

public func getFamilyKey() -> String {
    return familyKey!
}

public func getGeofences() -> [GeofenceData] {
    return geofences!
}

// left off here, trying to send geofence object to firebase
public func toDictionary() -> Any {
    return ["familyKey": familyKey, "geofences": geofences, "phoneNumber": phoneNumber]
}

}

和GeofenceData类:

And the GeofenceData class:

import Foundation
import Firebase

public class GeofenceData {
var name: String?
var latitude: Double?
var longitude: Double?
var radius: Float?

init() {

}

init(name: String?, latitude: Double, longitude: Double, radius: Float) {
    self.name = name
    self.latitude = latitude
    self.longitude = longitude
    self.radius = radius
}

// left off here, trying to send geofence object to firebase
public func toDictionary() -> Any {
    return ["name": name, "latitude": latitude, "longitude": longitude, "radius": radius]
}

public func getName() -> String {
    return name!
}

public func getLatitude() -> Double {
    return latitude!
}

public func getLongitude() -> Double {
    return longitude!
}

public func getRadius() -> Float {
    return radius!
}

public func setName(name: String?) {
    self.name = name
}

public func saveToFirebase(reference: DatabaseReference) {
    let dict = ["name": name, "latitude": latitude, "longitude": longitude, "radius": radius] as Any
    reference.child("geofences").child("0").setValue(dict)
}

}

推荐答案

父项不是Firebase识别的对象，因此会引发错误.

Parent is not an object that Firebase recognizes so it throws an error.

Firebase指南阅读和阅读写入数据显示了可以写入的四种对象.字符串，数字，字典，数组.

The Firebase guide Reading & Writing Data shows the four types of objects that can be written; String, Number, Dictionary, Array.

一种解决方案是在类中构建一个函数，以返回要写入的数据.

One solution is to build a function into the class that returns the data you want to write.

public class Parent {
    var phoneNumber: String?
    var familyKey: String?
    var geofences: [GeofenceData]?

    init() {
        self.phoneNumber = ""
        self.familyKey = ""
        self.geofences = nil
    }

    //other init functions

    func getParentDict() -> [String: Any] {

        let geoDict = ["name": name,
                       "latitude": latitude,
                       "longitude": longitude,
                       "radius": radius
        ]

        let zeroNode = ["0": geoDict]

        let dictForFirebase: [String: Any] = [
            "phoneNumber": phoneNumber,
            "familyKey": familyKey,
            "geofences": zeroNode
        ]

        return dictForFirebase
    }
}

在实践中

var tempGeofences = [GeofenceData]()
tempGeofences.append(GeofenceData(name: "Hello WOrld", latitude: 0, longitude: 0, radius: 1000))

let familyKey:String = String(Int.random(in: 1000...99999))
let uid:String = Auth.auth().currentUser!.uid
let phoneNumber = "1111111111"
let parent = Parent(phoneNumber: phoneNumber, familyKey: familyKey, geofences: tempGeofences)
let parentDict = parent.getParentDict
databaseRef.child(uid).setValue(parentDict)

但是，令人担忧的是以"0"作为键的子节点.看起来您可能正在使用数组.如果有很好的理由，但是在NoSQL数据库中使用数组通常会有更好的选择.请参阅旧版但仍然准确的Firebase帖子，名为 Arrays Evil

However, one concern is the child node with "0" as the key. That looks like you may be using an array. If there's a good reason that's fine but there are usually much better alternatives to using array's in NoSQL databases. See the legacy but still accurate Firebase post called Arrays Are Evil

每个注释/问题如何在"0"节点之后添加另一个子节点"

Per a comment/question 'how to add another child node following the "0" node"

假设我们知道父节点qSaEE ...，让我们添加一个"1"节点

Assume we know the parent node, qSaEE..., lets add a "1" node

let parentNode = "qSaEE..."
let geofenceRef = firebaseRef.child(parentNode).child("geofences")

let geoDict = ["name": name,
               "latitude": latitude,
               "longitude": longitude,
               "radius": radius
               ]

let oneNode = ["1": geoDict]

geofenceNode.setValue(oneNode)

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