Question

我正在尝试在xcode中构造一个解析查询，它接受通过前一个segue传递给视图控制器的对象数组，从这些对象创建一个objectId数组，并查询数组objectId中的完全匹配“MessageThread”类中的键“参与者”中的值

我一直在阅读解析文档，我能提出的最佳查询是containsAllObjectsIn：

显然，containsAllObjectsIn在某些条件下会起作用。但是，该查询仅检查键“参与者”中是否存在所有objectId。它不检查阵列是否相同。因此，查询将返回对象，虽然它们包含所有objectIds，但可能包含额外的objectIds。

为了对付这种负面影响，我对每个返回的对象进行检查，以查看返回对象中的objectIds是否与原始数组完全匹配。我已经在下面包含了视图控制器代码。

虽然我目前在下面解决的代码似乎在测试后按预期工作，但我不禁要知道必须有一种更有效的方法来检查数组是否通过PFQuery是相同的。< / p>

有关如何使此代码更好的任何想法或帮助？感谢。

import UIKit
import Parse

class MessageThreadViewController: UIViewController {

@IBOutlet weak var sendNewMessageButton: UIButton!

var participantsList:[PFObject] = []
var participantsListIds:[String] = []
var currentMessageThreadObject:PFObject?
var threadMessages:[PFObject] = []

override func viewDidLoad() {
    super.viewDidLoad()
    initialViewSetup()
    checkForExistingMessageThread()
}

func initialViewSetup() {
    sendNewMessageButton.isEnabled = false
    for participant in participantsList {
        participantsListIds.append(participant.objectId!)
    }
}

func checkForExistingMessageThread () {
    print("-------------------")
    print(participantsListIds)
    let query = PFQuery(className: "MessageThread")
    query.whereKey("participants", containsAllObjectsIn: participantsList)
    query.includeKey("messages")
    query.findObjectsInBackground(block: { (threads, error) in
        if error != nil {
            if let error = error {
                print(error)
            }
        } else {
            if let threads = threads {
                if threads.isEmpty {
                    print("no thread found. creating thread....")
                    self.createMessageThread()
                } else {
                    print("existing thread match(es) found")
                    var activeThreadFound = false
                    for thread in threads {
                        let returnedThreadParticipants = thread["participants"] as! [PFObject]
                        var returnedThreadParticipantsIds:[String] = []
                        for participant in returnedThreadParticipants {
                            returnedThreadParticipantsIds.append(participant.objectId!)
                        }
                        if returnedThreadParticipantsIds.containsSameElements(as: self.participantsListIds) {
                            activeThreadFound = true
                            print("thread identical match found")
                            self.currentMessageThreadObject = thread
                            self.sendNewMessageButton.isEnabled = true
                            if let queriedThreadMessages = thread["messages"] {
                                let queriedThreadMessagesAsObjects = queriedThreadMessages as! [PFObject]
                                self.threadMessages = queriedThreadMessagesAsObjects
                                self.messagesTableView.reloadData()
                                self.sendNewMessageButton.isEnabled = true
                            }
                            break
                        } else {

                            print("non-identical thread found")
                        }
                    }
                    if activeThreadFound == false {
                        print("matches were found, but no identical thread. Creating thread....")
                        self.createMessageThread()
                    }
                }
            }
        }
    })
}

func createMessageThread() {
    let newMessageThread = PFObject(className:"MessageThread")
    newMessageThread["participants"] = participantsList
    newMessageThread.saveInBackground(block: { (success, error) in
        if error != nil {
            if let error = error {
                print(error)
            }
        } else {
            self.checkForExistingMessageThread()
        }
    })

}

}

extension Array where Element: Comparable {
func containsSameElements(as other: [Element]) -> Bool {
    return self.count == other.count && self.sorted() == other.sorted()

}

Answer 1

我的另一个建议是尝试在同一个查询中组合containsIn和containsAllObjectsInArray。请尝试这样的事情：

let query = PFQuery(className: "MessageThread")
query.whereKey("participants", containsAllObjectsInArray: participantsList)
query.whereKey("participants", containedIn: participantsList)

解析PFQuery - 检查数组是否相同 - Swift

1 个答案: