Creating an indexed tableview using Realm in swift - ios

Question

I have a list of contacts stored in a realm database, and now I want display the names of the contacts in a table view. As a list this works fine and can be sorted in ascending order of names ok. I'm struggling with grouping these names for each letter in an index list. My code is filling each section with the same information.
My code looks like this:
var contacts: Results<ContactItem>!
var contactIndexTitles = [String]()
#IBOutlet weak var tblContacts: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
self.setupUI()
let contactIndex = "A B C D E F G H I J K L M N O P Q R S T U V W X Y Z"
contactIndexTitles = contactIndex.componentsSeparatedByString(" ")
self.reloadTheTable()
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
reloadTheTable()
}
func setupUI() {
tblContacts.delegate = self
tblContacts.dataSource = self
}
func reloadTheTable() {
do {
let realm = try Realm()
contacts = realm.objects(ContactItem).sorted("Name", ascending: true)
tblContacts.reloadData()
print("reload tbl \(contacts)")
} catch {
}
}
//willDisplayCell forRowAtIndexPath
func tableView(tableView: UITableView, willDisplayCell cell: UITableViewCell, forRowAtIndexPath indexPath: NSIndexPath) {
cell.backgroundColor = UIColor.clearColor()
}
//numberOfSectionsInTableView
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return contactIndexTitles.count
}
//sectionForSectionIndexTitle
func tableView(tableView: UITableView, sectionForSectionIndexTitle title: String, atIndex index: Int) -> Int{
return index
}
//titleForHeaderInSection
func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String?{
return self.contactIndexTitles[section] as String
}
//numberOfRowsInSection
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int
{
return contacts.count
}
//sectionIndexTitlesForTableView
func sectionIndexTitlesForTableView(tableView: UITableView) -> [String]? {
return contactIndexTitles as [String]
}
//cellForRowAtIndexPath
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
{
let identifer: String = "myCell"
var cell = tblContacts.dequeueReusableCellWithIdentifier(identifer)
if cell == nil {
cell = UITableViewCell(style: .Subtitle, reuseIdentifier: identifer)
}
let contactinfo = contacts[indexPath.row]
cell?.textLabel?.text = contactinfo.Name
cell?.detailTextLabel?.text = contactinfo.KeyNumber
return cell!
}
Any suggestions on how to filter the realm database and populate the sections correctly?
EDIT
So I've amended the code using the first link and the sample given and it's displaying ok.
TableViewController code:
var contacts: Results<ContactItem>!
var contactIndexTitles = String
class TableViewController: UITableViewController {
#IBOutlet weak var tblcontacts: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
self.setupUI()
self.reloadTheTable()
let contactIndex = "A B C D E F G H I J K L M N O P Q R S T U V W X Y Z"
contactIndexTitles = contactIndex.componentsSeparatedByString(" ")
//print(Realm.Configuration.defaultConfiguration.fileURL!)
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
reloadTheTable()
}
func setupUI() {
tblcontacts.registerClass(UITableViewCell.self, forCellReuseIdentifier: "cell")
}
func reloadTheTable() {
do {
let realm = try Realm()
contacts = realm.objects(ContactItem.self).sorted("Name")
tblcontacts.reloadData()
}
catch
{
}
}
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return contactIndexTitles.count
}
override func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
return contactIndexTitles[section]
}
override func sectionIndexTitlesForTableView(tableView: UITableView) -> [String]? {
return contactIndexTitles
}
override func tableView(tableView: UITableView?, numberOfRowsInSection section: Int) -> Int {
return contacts.filter("Name BEGINSWITH %#", contactIndexTitles[section]).count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tblcontacts.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath)
cell.textLabel?.text = contacts.filter("Name BEGINSWITH %#", contactIndexTitles[indexPath.section])[indexPath.row].Name
return cell
}
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath)
{
let contact : ContactItem = contacts[indexPath.row] //, contactIndexTitles[indexPath.section])
print(contact)
performSegueWithIdentifier("addContact", sender: contact)
print("Selected row at \(indexPath.row)")
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?)
{
if(segue.identifier == "addContact")
{
let viewController = segue.destinationViewController as! AddEntryViewController
viewController.contact = sender as! ContactItem
}
}
}
Now I have one more problem and thats the segue to the next controller. I can't seem to get the code correct to able to go to the correct row in the correct section.
How can I select the correct row from the correct section?

Answer 1

Here's a sample derived from https://stackoverflow.com/a/38797693/373262 for your models and specifying a hardcoded array of section titles as your comment above requested:
import UIKit
import RealmSwift
class ContactItem: Object {
dynamic var name = ""
dynamic var keyNumber = ""
convenience init(name: String, keyNumber: String) {
self.init()
self.name = name
self.keyNumber = keyNumber
}
}
let alphabet = (UnicodeScalar("A").value...UnicodeScalar("Z").value).flatMap(UnicodeScalar.init)
class ViewController: UITableViewController {
let items = try! Realm().objects(ContactItem.self).sorted(byProperty: "name")
override func viewDidLoad() {
super.viewDidLoad()
tableView.register(UITableViewCell.self, forCellReuseIdentifier: "cell")
let realm = try! Realm()
if realm.isEmpty {
try! realm.write {
realm.add(ContactItem(name: "Bailey", keyNumber: "0"))
realm.add(ContactItem(name: "Bella", keyNumber: "1"))
realm.add(ContactItem(name: "Max", keyNumber:"2"))
realm.add(ContactItem(name: "Lucy", keyNumber: "3"))
realm.add(ContactItem(name: "Charlie", keyNumber:"4"))
realm.add(ContactItem(name: "Molly", keyNumber: "5"))
realm.add(ContactItem(name: "Buddy", keyNumber: "6"))
realm.add(ContactItem(name: "Daisy", keyNumber: "7"))
}
}
}
func items(forSection section: Int) -> Results<ContactItem> {
return items.filter("name BEGINSWITH %#", alphabet[section].description)
}
override func numberOfSections(in tableView: UITableView) -> Int {
return alphabet.count
}
override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
return alphabet[section].description
}
override func tableView(_ tableView: UITableView?, numberOfRowsInSection section: Int) -> Int {
return items(forSection: section).count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
let contactinfo = items(forSection: indexPath.section)[indexPath.row]
cell.textLabel?.text = contactinfo.name
cell.detailTextLabel?.text = contactinfo.keyNumber
return cell
}
}
Here's the end result:
And a link to the Xcode project: https://static.realm.io/debug/RealmContacts.tgz