【发布时间】：2015-09-02 14:00:43
【问题描述】：
我刚刚开始使用 CloudKit，所以请耐心等待。
背景信息
在 WWDC 2015 上，苹果发表了关于 CloudKit 的演讲https://developer.apple.com/videos/wwdc/2015/?id=715
在本次演讲中，他们警告不要创建链接查询，而是推荐这种策略：
let firstFetch = CKFetchRecordsOperation(...)
let secondFetch = CKFetchRecordsOperation(...)
...
secondFetch.addDependency(firstFetch)
letQueue = NSOperationQueue()
queue.addOperations([firstFetch, secondFetch], waitUntilFinished: false)
示例结构
测试项目数据库包含宠物及其主人，如下所示：
|Pets | |Owners |
|-name | |-firstName |
|-birthdate | |-lastName |
|-owner (Reference) | | |
我的问题
我正在尝试查找属于某个所有者的所有宠物，但我担心我正在创建链式苹果警告。请参阅下面的两种方法，它们做同样的事情，但有两种方式。哪个更正确或两者都错？我觉得我在做同样的事情，但只是使用了完成块。
我很困惑如何更改 otherSearchBtnClick: 以使用依赖项。我需要在哪里添加
ownerQueryOp.addDependency(queryOp)
在 otherSearchBtnClick 中：？
@IBAction func searchBtnClick(sender: AnyObject) {
var petString = ""
let container = CKContainer.defaultContainer()
let publicDatabase = container.publicCloudDatabase
let privateDatabase = container.privateCloudDatabase
let predicate = NSPredicate(format: "lastName == '\(ownerLastNameTxt.text)'")
let ckQuery = CKQuery(recordType: "Owner", predicate: predicate)
publicDatabase.performQuery(ckQuery, inZoneWithID: nil) {
record, error in
if error != nil {
println(error.localizedDescription)
} else {
if record != nil {
for owner in record {
let myRecord = owner as! CKRecord
let myReference = CKReference(record: myRecord, action: CKReferenceAction.None)
let myPredicate = NSPredicate(format: "owner == %@", myReference)
let petQuery = CKQuery(recordType: "Pet", predicate: myPredicate)
publicDatabase.performQuery(petQuery, inZoneWithID: nil) {
record, error in
if error != nil {
println(error.localizedDescription)
} else {
if record != nil {
for pet in record {
println(pet.objectForKey("name") as! String)
}
}
}
}
}
}
}
}
}
@IBAction func otherSearchBtnClick (sender: AnyObject) {
let container = CKContainer.defaultContainer()
let publicDatabase = container.publicCloudDatabase
let privateDatabase = container.privateCloudDatabase
let queue = NSOperationQueue()
let petPredicate = NSPredicate(format: "lastName == '\(ownerLastNameTxt.text)'")
let petQuery = CKQuery(recordType: "Owner", predicate: petPredicate)
let queryOp = CKQueryOperation(query: petQuery)
queryOp.recordFetchedBlock = { (record: CKRecord!) in
println("recordFetchedBlock: \(record)")
self.matchingOwners.append(record)
}
queryOp.queryCompletionBlock = { (cursor: CKQueryCursor!, error: NSError!) in
if error != nil {
println(error.localizedDescription)
} else {
println("queryCompletionBlock: \(cursor)")
println("ALL RECORDS ARE: \(self.matchingOwners)")
for owner in self.matchingOwners {
let ownerReference = CKReference(record: owner, action: CKReferenceAction.None)
let ownerPredicate = NSPredicate(format: "owner == %@", ownerReference)
let ownerQuery = CKQuery(recordType: "Pet", predicate: ownerPredicate)
let ownerQueryOp = CKQueryOperation(query: ownerQuery)
ownerQueryOp.recordFetchedBlock = { (record: CKRecord!) in
println("recordFetchedBlock (pet values): \(record)")
self.matchingPets.append(record)
}
ownerQueryOp.queryCompletionBlock = { (cursor: CKQueryCursor!, error: NSError!) in
if error != nil {
println(error.localizedDescription)
} else {
println("queryCompletionBlock (pet values)")
for pet in self.matchingPets {
println(pet.objectForKey("name") as! String)
}
}
}
publicDatabase.addOperation(ownerQueryOp)
}
}
}
publicDatabase.addOperation(queryOp)
}
【问题讨论】：
-
没有回复是因为我离基地太远了我绝望了吗？！