ios - 如何在 Xcode 项目中将字典数组写入 .txt 文件

Question

我从 Firebase 检索数据，然后将接收到的 FIRDataSnapshot 类型的数组转换为 [String:Any] 类型的字典数组。我如何将这个字典数组输出到我的 Xcode 项目中的有序列表中的 .txt 文件？

txt文件中打印的输出应该是这样的格式:

预订 1:
邮箱地址:johnmm@gmail.com
电话号码:94949392
.
.
预订 4:
邮箱地址:chris@gmail.com
电话号码:202583963

在我问题的底部，您会发现原始数据在 finalDictionary 中的样子

我认为逻辑应该是这样的:1. 遍历 finalDictionary 的元素2. 取出数组的每个元素，为其分配一个计数+断行

let finalDictionary = [String:Any]()

func startObservingDB() {

  dbRef.child(FullData.uid!).observe(.value, with: { (snapshot: FIRDataSnapshot) in

        // an instance of FireBaseData holding all bookings under currentUid
        var newBookingInfo = [FireBaseData]()

//iterate over all children under /FullData.uid! path
   for customer in snapshot.children {

      //the customer node starting with cus...
        let customerObject = customer as! FIRDataSnapshot

       //customer key
          self.customerKey = customerObject.key
             print("this is the Stripe customer that can be charged \(customerObject.key)")

   //now iterate over each booking which is located under customerObject in Firebase
     for booking in customerObject.children {


         // after each iteration through snapshot.children, create an instance of FireBaseData with  'booking' for the current iteration & assign it to bookingItem
            var bookingItem = FireBaseData(snapshot: booking as! FIRDataSnapshot)

        //assign key of the parent to each booking
                bookingItem.Key = self.customerKey

            // append the bookingItem after each iteration to newBookingInfo array
            newBookingInfo.append(bookingItem)

         } // end of  for booking in myCustomer
    } // end of  for customer in snapshot.children

         //assign newBookingInfo to global variable bookingInfo so it can be used globally within the class
         self.bookingInfo = newBookingInfo

  // sort the array in place so that the most recent date will appear first
 self.bookingInfo.sort(by: {(DateAndTimeObject_1,DateAndTimeObject_2) -> Bool in

     DateAndTimeObject_1.TimeStampDateAndTime > DateAndTimeObject_2.TimeStampDateAndTime
  })


  // convert bookingInfo of type FIrebaseData to Array of Dictionaries
   let arrayOfDictionary = self.bookingInfo.flatMap { $0.toAnyObject() as? [String:Any] }

  finalDictionary =  arrayOfDictionary
   print("arrayOfDictionary is \(arrayOfDictionary)")

 //I can write a string to a file in Xcode project using the code snippet 
 //below, but this does not solve my problem, namely to output all elements 
 //of the array as specified above with a break space after each element 
//so that they can be in a human readable format. 

 let fileName = "myBookings"
  let dir = try? FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: true)

  // If the directory was found, we write a file to it
     if let fileURL = dir?.appendingPathComponent(fileName).appendingPathExtension("txt") {

     // Write to the file
     let outString = "Write this text to the file"
     do {
         try outString.write(to: fileURL, atomically: true, encoding: .utf8)
     } catch {
         print("Failed writing to URL: \(fileURL), Error: " + error.localizedDescription)
    }   
}




          self.tableView.reloadData()
      }, withCancel: { (Error:Any) in
        print("Error firebase \(Error)")
    })
  } // end of startObservingDB()



func exportBookings(){

 let path = URL(string: "file:///Users/bogdanbarbulescu/Desktop/Test.txt")

        //writing
        do {  
            try (finalDictionary).description.write(to: path!, atomically: false, encoding: .utf8)
        }
        catch let error { print("The error is \(error.localizedDescription)") 
   }
}

print("arrayOfDictionary is (arrayOfDictionary)") 的输出是:

arrayof Dict is [["EmailAddress": johnmm@gmail.com, "PhoneNumber": 94949392, "PaymentID": ch_1AVK6KLCZ34Ur7XGsbROjWhe, "BookingAmount": 37, "BookingCompleted": 0, "NoteInstructions": Take the dog out please, "insideCabinets": true, "BookingNumber": 883924391, "BookingStatusAdmin": 0, "insideFridge": true, "FrequencyName": Every 2 weeks, "EntryInstructions": keys under carpet, "FullName": James, "SuppliesAmount": 0, "FirebaseUserID": 7b1eRsa9QWhdtA5EwyD2FiPZHSh2, "TimeStampDateAndTime": 1497790800, "PostCode": W3 7RZ, "SelectedBathRow": 2, "FrequecyAmount": 22, "laundryWash": false, "StreetAddress": 11 High St, "CostToRescheduleClient": 0, "BookingStatusClient": 1, "TimeStampBookingSavedInDB": 1497618179, "FlatNumber": Conely, "SelectedBedRow": 1, "interiorWindows": 0, "CostToCancelClient": 0, "DoormanOption": Hidden-Key, "DateAndTime": Sun, 18 Jun 2017 14:00, "insideOven": true, "SuppliesName": I have cleaning supplies],

[“EmailAddress": johnmm@gmail.com, "PhoneNumber": 07476953923, "PaymentID": ch_1ATTRHLCZ34Ur7XGL2CGN1I3, "BookingAmount": 63, "BookingCompleted": 0, "NoteInstructions": No, "insideCabinets": true, "BookingNumber": 173009560, "BookingStatusAdmin": 1, "insideFridge": true, "FrequencyName": Every 2 weeks, "EntryInstructions": simbasdada, "CostToRescheduleAdmin": 0, "FullName": John Luch, "SuppliesAmount": 5, "FirebaseUserID": 7b1eRsa9QWhdtA5EwyD2FiPZHSh2, "TimeStampDateAndTime": 1497632400, "PostCode": IG11 6PP, "SelectedBathRow": 2, "FrequecyAmount": 33, "laundryWash": true, "StreetAddress": High St, "CostToRescheduleClient": 0, "BookingStatusClient": 1, "TimeStampBookingSavedInDB": 1497177419, "FlatNumber": Flat 11, "SelectedBedRow": 2, "interiorWindows": 0, "DoormanOption": Hidden-Key, "DateAndTime": Fri, 16 Jun 2017 18:00, "insideOven": false, "SuppliesName": Bring cleaning supplies]]

Answer 1

如果您只想以“有序/可读”格式输出字典数组，您可以使用以下命令:

if let orderedKeys = finalDictionary.first?.keys {

    var outputString = ""
    var i = 1

    for d in finalDictionary {
        outputString += "Booking \(i):\n"
        for k in orderedKeys {
            outputString += k + ": " + (d[k] ?? "(no value)") + "\n"
        }
        outputString += "\n"
        i += 1
    }

    print(outputString)
    // or, write outputString to a text file

}

注意:这只是快速代码...不一定是最佳的或 100% 无错误，并且假设所有记录都具有相同的键。更多的是“这是一个方向”之类的东西:)

编辑:如果字典可能有可变的键集，您可以执行以下操作:

var outputString = ""
var i = 1
for d in finalDictionary {
    outputString += "Booking \(i):\n"
    for k in d.keys {
        outputString += k + ": " + (d[k] ?? "(no value)") + "\n"
    }
    outputString += "\n"
    i += 1
}

print(outputString)

编辑2:可能是一种“更迅速”的做法:

outputString = ""
i = 1

finalDictionary.forEach {
    outputString += "Booking \(i):\n"
    $0.forEach { outputString += "\($0): \($1)\n" }
    outputString += "\n"
    i += 1
}

print(outputString)

因为字典是无序的，所以你最终可能会得到:

Booking 1:
EmailAddress: johnmm@gmail.com
PhoneNumber: 94949392
FullName: John
.
Booking 2:
SomeOtherKey: Some Value
FullName: Dave
EmailAddress: dave@gmail.com
.
Booking 3:
FullName: Chris
PhoneNumber: 202583963
SomeOtherKey: Some Other Value
EmailAddress: chris@gmail.com

等等。