我使用Firebase 3.0作为我的后端，我需要将每个user.uid保存在一个需要为NSArray的单独子项中，然后使用for循环检索该数组！
这就是我保存数据的方式：我为FIRController创建了一个单独的类，它处理数据库和存储的所有存储和检索。
func signUpUserWithBasicInfo(emailId : String! , password : String!, username : String!, age : String, gender : String!, backpackerType : String, info : [String : AnyObject], completionBlock : (() -> Void)){
print("fir signup did recieve")
FIRAuth.auth()?.createUserWithEmail(emailId, password: password, completion: {
user,error in
if error != nil{
print("error encountered while backend email signup Handshake : \(error)")
print("")
self.delegate.firShowAlert("Error signing you up", Message: "Please check your network or this email already exist!")
}else{
print("uploading database")
self.profilePictureUploading(info, completionBlock: {
FIRControllerClass.ref.child("UserProfile").child(user!.uid).setValue([
"username" : username,
"email" : emailId,
"age" : age,
"gender" : gender,
"password" : password,
"typeOfBackpacker" : backpackerType
])
completionBlock()
})
}
})
}
func profilePictureUploading(infoOnThePicture : [String : AnyObject],completionBlock : (()->Void)) {
if let referenceUrl = infoOnThePicture[UIImagePickerControllerReferenceURL] {
print(referenceUrl)
let assets = PHAsset.fetchAssetsWithALAssetURLs([referenceUrl as! NSURL], options: nil)
print(assets)
let asset = assets.firstObject
print(asset)
asset?.requestContentEditingInputWithOptions(nil, completionHandler: { (ContentEditingInput, infoOfThePicture) in
let imageFile = ContentEditingInput?.fullSizeImageURL
print("imagefile : \(imageFile)")
let filePath = FIRAuth.auth()!.currentUser!.uid + "/\(Int(NSDate.timeIntervalSinceReferenceDate() * 1000))/\(imageFile!.lastPathComponent!)"
print("filePath : \(filePath)")
FIRControllerClass.storageRef.child("ProfilePictures").child(filePath).putFile(imageFile!, metadata: nil, completion: { (metadata, error) in
if error != nil{
print("error in uploading image : \(error)")
self.delegate.firShowAlert("Error Uploading Your Profile Pic", Message: "Please check your network!")
}
else{
print("metadata in : \(metadata!)")
print(metadata?.downloadURL())
print("The pic has been uploaded")
print("download url : \(metadata?.downloadURL())")
self.uploadSuccess(metadata!, storagePath: filePath)
completionBlock()
}
})
})
} else {
print("No reference URL found!")
}
}
我如何在后端创建一个用作数组的子节点，如何检索该数组？
我的firebase JSON STRUCTURE： -
{
"UserId" : [ 1,
"Sq5EDvVOsQWkLylEx3GrBdEsIN92",
"xC4jCJmobUcqghq8C3SI1XT0UPk1",
"D8QmnOSH6vRYiMujKNXngzhdn992",
"riHjon6wknOmALwf0Z0Ri5aOMA82",
"fKqlb88MKsYCE43xy7D51qH6jqH3",
"aCgAFAGDIgWRSUu9a2aMo9HtnnD3",
"iicKACGo8RaeTSEggKPB0sU2Bme2",
"qJ2c8AcEYzVkJKLl13N92tyKnbz2"
],
"UserProfile" : {
"D8QmnOSH6vRYiMujKNXngzhdn992" : {
"age" : "12",
"email" : "dummy1@gmail.com",
"gender" : "f",
"password" : "123454321",
"typeOfBackpacker" : "dummy",
"username" : "duummyy1"
},
"Sq5EDvVOsQWkLylEx3GrBdEsIN92" : {
"age" : "121",
"email" : "ghfgh@gnag.com",
"gender" : "gjhg",
"password" : "123454321",
"typeOfBackpacker" : "chef",
"username" : "hgfgh"
},
"aCgAFAGDIgWRSUu9a2aMo9HtnnD3" : {
"age" : "24",
"email" : "cathydurrant@gmail.com",
"gender" : "F",
"password" : "123454321",
"typeOfBackpacker" : "Group",
"username" : "Cathy"
},
etc
}
我还需要在我的数据库（数组）中添加一个no of friends数组。我使用for循环的唯一原因是我可以向用户显示每个用户的详细信息（除了他/她自己） ）使用我在我的数据库中创建的userId数组，它实际上是我每个用户数据库的父节点。
这就是我在数据库中附加UserId的方式： -
func retrieveUserIdsArray(completionBlock : ((appendedArr : NSMutableArray) -> Void)){
var appendedArray : NSMutableArray = []
FIRControllerClass.ref.child("UserId").observeEventType(FIRDataEventType.Value, withBlock: {(snapshot) in
if let userIdDetails = snapshot.value as? NSMutableArray{
userIdDetails.addObject((FIRAuth.auth()?.currentUser?.uid)!)
appendedArray = userIdDetails
completionBlock(appendedArr: appendedArray)
}
})
}
在此函数中调用： -
func signUpUserWithBasicInfo(emailId : String! , password : String!, username : String!, age : String, gender : String!, backpackerType : String, info : [String : AnyObject], completionBlock : (() -> Void)){
print("fir signup did recieve")
FIRAuth.auth()?.createUserWithEmail(emailId, password: password, completion: {
user,error in
if error != nil{
print("error encountered while backend email signup Handshake : \(error)")
print("")
self.delegate.firShowAlert("Error signing you up", Message: "Please check your network or this email already exist!")
}else{
print("uploading database")
self.profilePictureUploading(info, completionBlock: {
FIRControllerClass.ref.child("UserProfile").child(user!.uid).setValue([
"username" : username,
"email" : emailId,
"age" : age,
"gender" : gender,
"password" : password,
"typeOfBackpacker" : backpackerType
])
var a = 0
self.retrieveUserIdsArray({ (appendedArr) in
a += 1
print("The appended array is : \(appendedArr)")
if a == 1{
FIRControllerClass.ref.child("UserId").setValue(appendedArr)
}else{
completionBlock()
}
})
})
}
})
}
我使用a变量的原因是为了解决它导致的无限循环（我知道它只是一个黑客，现在......）
打开任何更好的方法来解决这个问题！..
答案 0 :(得分：2)
阵列在Firebase中可能具有挑战性，因为无法直接访问或修改单个元素。您可以读取整个数组，也可以编写整个数组。
我建议更改结构以更好地匹配您想要的数据并完全避免数组：
"UserProfile" : {
"D8QmnOSH6vRYiMujKNXngzhdn992" : {
"age" : "12",
"email" : "dummy1@gmail.com",
"gender" : "f",
"password" : "123454321",
"typeOfBackpacker" : "dummy",
"username" : "duummyy1"
"friend_count": 10
"friend_of"
"aCgAFAGDIgWRSUu9a2aMo9HtnnD3": true
},
然后一个简单的深度查询将返回您需要的所有内容（Firebase v2）
let myUid = "aCgAFAGDIgWRSUu9a2aMo9HtnnD3"
let path = ("friend_of/\(myUid)") // equals friend_of/aCgAFAGDIgWRSUu9a2aMo9HtnnD3
var userIdArray = [String]()
userProfileRef.queryOrderedByChild(path)
.queryEqualToValue(true)
.observeSingleEventOfType(.Value, withBlock: { snapshot in
for child in snapshot.children {
let userId = child.key as String
userIdArray.append(userId)
}
//loop is done, now we have an array of userIds that are friends
})
代码返回我的朋友（myUid）的每个用户
我还添加了一个朋友数量＆＃39;只保留该用户数量的朋友的节点。添加朋友时，在删除减量时递增值。这是一个快速的
myUid.child("friend_count").setValue(updated_count)
此代码还避免了循环，回调和其他完成块，因为它依赖于Firebase来获取数据，并让我们知道它何时完成。
如果你真的，真的想读一个数组节点（不推荐）
let myRef = self.myRootRef.child("array_node")
myRef.observeSingleEventOfType(.Value, withBlock: { snapshot in
let a = snapshot.value as! NSArray
print(a) //a an NSArray
let b = (a as Array).filter {$0 is String}
print(b) //b is a Swift Array
print( b[1] )
})