Reordering Realm.io data in tableView with Swift - xcode

Question

I have implemented a basic example of an ios app using Realm.io
I'd like to be able to reorder table rows in my iOS app and save the order back to Realm.
Realm model contains a property called position for this purpose.
P.S: Sorry for so much code.
import UIKit
import Realm
class Cell: UITableViewCell {
var position: Int!
init(style: UITableViewCellStyle, reuseIdentifier: String!) {
super.init(style: .Subtitle, reuseIdentifier: reuseIdentifier)
}
}
class Language: RLMObject {
var title = ""
var position = Int()
}
class ManagerLanguagesController: UITableViewController, UITableViewDelegate, UITableViewDataSource {
var array = RLMArray()
var notificationToken: RLMNotificationToken?
var editButton = UIBarButtonItem()
override func viewDidLoad() {
super.viewDidLoad()
setupUI()
notificationToken = RLMRealm.defaultRealm().addNotificationBlock { note, realm in
self.reloadData()
}
reloadData()
}
override func tableView(tableView: UITableView?, numberOfRowsInSection section: Int) -> Int {
return Int(array.count)
}
func setupUI() {
tableView.registerClass(Cell.self, forCellReuseIdentifier: "cell")
self.title = "Languages"
var addButton = UIBarButtonItem(barButtonSystemItem: .Add, target: self, action: "add")
editButton = UIBarButtonItem(title: "Edit", style: .Plain, target: self, action: "edit")
var buttons = [addButton, editButton]
self.navigationItem.rightBarButtonItems = buttons
}
func add() {
var addLanguageView:UIViewController = self.storyboard.instantiateViewControllerWithIdentifier("newLanguage") as UIViewController
self.navigationController.presentViewController(addLanguageView, animated: true, completion: nil)
}
func edit () {
if tableView.editing {
/* FROM THIS POINT I'M PROBABLY DOING SOMETHING WRONG.. IT IS NOT WORKING */
var positionArray = NSMutableArray()
let realm = RLMRealm.defaultRealm()
var i = 0
for var row = 0; row < tableView.numberOfRowsInSection(0); row++ {
var cellPath = NSIndexPath(forRow: row, inSection: 0)
var cell:Cell = tableView.cellForRowAtIndexPath(cellPath) as Cell
positionArray.addObject(cell.position)
}
realm.beginWriteTransaction()
for row: RLMObject in array {
row["position"] = positionArray[i]
i++
}
realm.commitWriteTransaction()
/* -- NOT WORKING END -- */
tableView.setEditing(false, animated: true)
editButton.style = UIBarButtonItemStyle.Plain
editButton.title = "Edit"
} else{
tableView.setEditing(true, animated: true)
editButton.title = "Done"
editButton.style = UIBarButtonItemStyle.Done
}
}
override func tableView(tableView: UITableView?, cellForRowAtIndexPath indexPath: NSIndexPath?) -> UITableViewCell? {
let cell = tableView!.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as Cell
let object = array[UInt(indexPath!.row)] as Language
cell.textLabel.text = object.title
cell.position = object.position // I have implemented this to be able to retain initial positions for each row and maybe use this when reordering..
return cell
}
override func tableView(tableView: UITableView!, canMoveRowAtIndexPath indexPath: NSIndexPath!) -> Bool {
return true
}
override func tableView(tableView: UITableView!, moveRowAtIndexPath sourceIndexPath: NSIndexPath!, toIndexPath destinationIndexPath: NSIndexPath!) {
// println("Old index: \(sourceIndexPath.indexAtPosition(sourceIndexPath.length - 1)+1)")
// println("New index: \(destinationIndexPath.indexAtPosition(sourceIndexPath.length - 1)+1)")
// Maybe something needs to be implemented here instead...
}
func reloadData() {
array = Language.allObjects().arraySortedByProperty("position", ascending: true)
tableView.reloadData()
}
}
Thanks in advance

Answer 1

Instead of using a position property, you could instead keep an ordered array as a property on another object. This way you don't have to keep the position up to date and instead arrange your objects as needed:
class Language: RLMObject {
dynamic var title = ""
}
class LanguageList: RLMObject {
dynamic var languages = RLMArray(objectClassName: "Language")
}
class ManagerLanguagesController: UITableViewController, UITableViewDelegate, UITableViewDataSource {
override func viewDidLoad() {
super.viewDidLoad()
// create our list
var realm = RLMRealm.defaultRealm()
realm.beginWriteTransaction()
realm.addObject(LanguageList())
realm.commitWriteTransaction()
...
}
// helper to get the RLMArray of languages in our list
func array() -> RLMArray {
return (LanguageList.allObjects().firstObject() as LanguageList).languages
}
override func tableView(tableView: UITableView!, moveRowAtIndexPath sourceIndexPath: NSIndexPath!, toIndexPath destinationIndexPath: NSIndexPath!) {
var languages = array()
var object = languages.objectAtIndex(UInt(sourceIndexPath.row)) as Language
var realm = RLMRealm.defaultRealm()
realm.beginWriteTransaction()
languages.removeObjectAtIndex(UInt(sourceIndexPath.row))
languages.insertObject(object, atIndex: UInt(destinationIndexPath.row))
realm.commitWriteTransaction()
}
...
}

Answer 2

this work for me to move rows in tableview using realm with swift 2.2:
func tableView(tableView: UITableView, moveRowAtIndexPath fromIndexPath: NSIndexPath, toIndexPath: NSIndexPath) {
let aux = TimesHome.mutableCopy() as! NSMutableArray
let itemToMove = aux[fromIndexPath.row]
let realm = try! Realm()
realm.beginWrite()
aux.removeObjectAtIndex(fromIndexPath.row)
aux.insertObject(itemToMove, atIndex: toIndexPath.row)
try! realm.commitWrite()
TimesHome = aux
let times = realm.objects(ParciaisTimes)
if times.count > 0 {
for tm in times {
for i in 1...aux.count {
if aux[i-1].valueForKey("time_id") as! Int == tm.time_id {
realm.beginWrite()
tm.ordem = i
try! realm.commitWrite()
}
}
}
}
}