How to write an array of dictionaries to a .txt file in Xcode Project

I am retrieving the data from Firebase, then I convert the array received of type FIRDataSnapshot into an array of dictionaries of type [String:Any]. How can I output this array of dictionaries to a .txt file in my Xcode-project in an ordered list?

The output printed in the txt file should be in this format:

Booking 1:
EmailAddress: [email protected]
PhoneNumber: 94949392
.
.
Booking 4:
EmailAddress: [email protected]
PhoneNumber: 202583963

At the bottom of my question you will find the raw data how it looks in finalDictionary

I think the the logic should be like this: 1. loop through the elements of finalDictionary 2. take each element of the array, assign a count to it + break line

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)") 
   }
}

The output of print("arrayOfDictionary is (arrayOfDictionary)") is :

arrayof Dict is [["EmailAddress": [email protected], "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": [email protected], "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]]

Solution

If all you want to do is output your Array of Dictionaries in an "orderly / readable" format, you can use this:

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

}

Note: this is just quick code... not necessarily optimal or 100% error free, and assumes all records have the same keys. More of a "here's a direction to go" kinda thingy :)

Edit: If the dictionaries may have variable sets of keys, you can do this:

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)

Edit 2: probably a little "Swiftier" way of doing it:

outputString = ""
i = 1

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

print(outputString)

Because Dictionaries are unordered, you may end up with:

Booking 1:
EmailAddress: [email protected]
PhoneNumber: 94949392
FullName: John
.
Booking 2:
SomeOtherKey: Some Value
FullName: Dave
EmailAddress: [email protected]
.
Booking 3:
FullName: Chris
PhoneNumber: 202583963
SomeOtherKey: Some Other Value
EmailAddress: [email protected]

and so on.