问题描述
我正在尝试按ranking降序获取数据（帖子）。当其他用户与帖子互动时，更改此排名。最初发布该帖子时，其起始排名为0.0。
问题
当前正在发生什么： 目前，我按排名以DESC顺序获取我的第一批10条帖子，但是当我到达10的末尾而不是获取下一批10条帖子时，它什么也不会获取。
代码
重要部分：
第一个电话：
ref.child("Hashtags").child(currentHashtag).child("posts")//ref.child("Timeline").child((Auth.auth().currentUser?.uid)!)
.queryOrdered(byChild: queryOrderdBy)
.queryLimited(toLast: 10)
.observeSingleEvent(of: .value,with: { (snapshot) in
呼叫通话：
let lastRanking = (postArray.last!.interimMedia.first!.ranking)
let postRef = ref.child("Hashtags").child(currentHashtag).child("posts")
postRef.queryOrdered(byChild: queryOrderdBy)
.queryEnding(atValue: lastRanking)
.queryLimited(toLast: UInt(limit))//10
.observeSingleEvent(of: .value,with: { (snapshot) in
func getRecentExplorePosts(limit: Int,wasCalledOnP3: Bool) {
let ref = Database.database().reference()
// if GlobalSharedData.shared.isOnFollowingOption {
if postArray.count == 0 {
ref.child("Hashtags").child(currentHashtag).child("posts")//ref.child("Timeline").child((Auth.auth().currentUser?.uid)!)
.queryOrdered(byChild: queryOrderdBy)
.queryLimited(toLast: 10)
.observeSingleEvent(of: .value,with: { (snapshot) in
self.totalItems = snapshot.children.allObjects.count
//var i = 0
for case let child as DataSnapshot in snapshot.children.reversed() {//.reversed()
var runAll = true
let keyvalue = child.key
let uid = keyvalue.split(separator: ":")[0]
let postIDDoubleVal = keyvalue.split(separator: ":")[1]
let timelineTimestamp = child.childSnapshot(forPath: "timeStamp").value as! Double
if (nil == child.childSnapshot(forPath: "ranking").value as? Double) {
print("fldjsahajasdhfkdsahfjdashfjksdahfjksda")
self.totalItems-=1
if snapshot.children.allObjects.count == 0 || self.totalItems == 0 {
self.hasFetched = true
self.postsCollectionView.reloadData()
self.refreshControl.endRefreshing()
self.postsCollectionView.isUserInteractionEnabled = true
} else if self.totalItems == self.postArray.count {
self.hasFetched = true
self.postsCollectionView.reloadData()
self.refreshControl.endRefreshing()
self.postsCollectionView.isUserInteractionEnabled = true
}
//break;
runAll = false
}
if runAll {
let timelineRanking = child.childSnapshot(forPath: "ranking").value as! Double
self.fetchUsersPost(uid: "\(uid)",postID: "post:\(postIDDoubleVal)",timelineTimeStamp: timelineTimestamp) { post in
if post != nil {
post?.interimMedia.first?.ranking = timelineRanking
self.postArray.append(post!)
if self.totalItems == self.postArray.count {
self.hasFetched = true//snapshot.children.allObjects.count > 0
self.postsCollectionView.reloadData()
self.refreshControl.endRefreshing()
self.postsCollectionView.isUserInteractionEnabled = true
}
} else {
print("ffdasfdasfdsafadsksdafjkhdsad")
self.totalItems-=1
if snapshot.children.allObjects.count == 0 || self.totalItems == 0 {
self.hasFetched = true
self.postsCollectionView.reloadData()
self.refreshControl.endRefreshing()
self.postsCollectionView.isUserInteractionEnabled = true
} else if self.totalItems == self.postArray.count {
self.hasFetched = true
self.postsCollectionView.reloadData()
self.refreshControl.endRefreshing()
self.postsCollectionView.isUserInteractionEnabled = true
}
}
}
}
}
if snapshot.children.allObjects.count == 0 || self.totalItems == 0 {
self.hasFetched = true
self.postsCollectionView.reloadData()
self.refreshControl.endRefreshing()
self.postsCollectionView.isUserInteractionEnabled = true
} else if self.totalItems == self.postArray.count {
self.hasFetched = true
self.postsCollectionView.reloadData()
self.refreshControl.endRefreshing()
self.postsCollectionView.isUserInteractionEnabled = true
}
})
} else {
// let lastTimeStamp = (postArray.last!.interimMedia.first!.timelineTimeStamp!)
let lastRanking = (postArray.last!.interimMedia.first!.ranking)
let postRef = ref.child("Hashtags").child(currentHashtag).child("posts")
postRef.queryOrdered(byChild: queryOrderdBy)
.queryEnding(atValue: lastRanking)
.queryLimited(toLast: UInt(limit))//10
.observeSingleEvent(of: .value,with: { (snapshot) in
print(snapshot.children.allObjects.count-1," fdsjhafljkdsahfljksadhjklfdhsajfkhadsfhjkadsfjhladsjl;")
self.totalItems += snapshot.children.allObjects.count-1
//var i = 0
for case let child as DataSnapshot in snapshot.children.reversed() {
var runAll = true
let keyvalue = child.key
let postIDDoubleVal = keyvalue.split(separator: ":")[1]
let timelineTimestamp = child.childSnapshot(forPath: "timeStamp").value as! Double
if (nil == child.childSnapshot(forPath: "ranking").value as? Double) {
//the problem has to do with the fact that the pst with aa problm is the last one.
print("fdsdsfdsflkjshfjkshkfsd",self.totalItems)
self.totalItems-=1
if self.totalItems == self.postArray.count {
self.postsCollectionView.reloadData()
self.refreshControl.endRefreshing()
self.postsCollectionView.isUserInteractionEnabled = true
if let p3 = self.p3Refrence {
if wasCalledOnP3 {
p3.updatePageVCInExplore(postARR: self.postArray)
}
}
}
runAll = false
}
if runAll {
let timelineRanking = child.childSnapshot(forPath: "ranking").value as! Double
if lastRanking != timelineRanking {
let uid = keyvalue.split(separator: ":")[0]
self.fetchUsersPost(uid: "\(uid)",timelineTimeStamp: timelineTimestamp) { post in
if post != nil {
post?.interimMedia.first?.ranking = timelineRanking
self.postArray.append(post!)
print(self.totalItems,"==",self.postArray.count," fjsdhafjksdlahfjklhsdafjkdhddasljkf")
if self.totalItems == self.postArray.count {
self.postsCollectionView.reloadData()
self.refreshControl.endRefreshing()
self.postsCollectionView.isUserInteractionEnabled = true
if let p3 = self.p3Refrence {
if wasCalledOnP3 {
p3.updatePageVCInExplore(postARR: self.postArray)
}
}
}
} else {
//the problem has to do with the fact that the pst with aa problm is the last one.
print("fdshjakdhjskfjdhksdafjkhdsad",self.totalItems)
self.totalItems-=1
if self.totalItems == self.postArray.count {
self.postsCollectionView.reloadData()
self.refreshControl.endRefreshing()
self.postsCollectionView.isUserInteractionEnabled = true
if let p3 = self.p3Refrence {
if wasCalledOnP3 {
p3.updatePageVCInExplore(postARR: self.postArray)
}
}
}
print("fdshjakdhjskfjdhksdafjkhdsad",self.totalItems)
}
}
} else {
}
}
}
})
}
// }
}
额外：在研究此问题时，我遇到了这个Query rows using Order by A,if A values are the same,Order by B as the second standard，其含义在我的提取中没有看到。
解决方法
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