How to present data, saved in Realm, in another viewController's tableViewCells? - ios

Question

I'm trying to make an app, in which one of the functions is, that in one viewController, the user can enter some data about a given person (a photo, a name and an answer to a certain question). When pressing the "save new person-button", the user is to be redirected to the previous viewController, which amongst other things holds a tableView.
In this tableView, I want there to be created a new cell for each time the user presses the "save new person-button" in the other viewController. The cell should, of course, hold the person's name (and ideally also a miniature of the photo).
Now, it is important that the data is stored 'internally' - also after exiting a certain viewController or closing the app. Therefore I'm using Realm as a database to store all the data.
I'm very new when it comes to using Realm, so maybe my questions seem stupid. Basically, I think I have been able to make the "Save new person-button" save all the data in the realm database. But when trying to make the button create new cells (which must stay, once created!!) in the previous viewController... All kinds of weird things happen!
What the code underneath shows is my current attempt on passing at least the name through a segue, but that creates several problems: The cells don't stay. If you try to add a new cell, it just overrides the old one. And finally, the PeopleData.count apparently counts the number of letters in the name - and creates fx. 5 identical cells for a 5 letter long name! :D
I'm sure this is not the right way to pass the data ... So what is the best way to present this data? So that the cells stay once created - and so that the user can add several new people/several new cell without overriding the old ones!
Relevant code:
viewController where the user can enter the data:
#IBAction func SaveNewPerson() {
let NewPerson = person()
NewPerson.name = PersonName.text!
NewPerson.answer = PersonAnswer.text!
NewPerson.extraIdentifier = PersonExtraIdentifier.text!
let realm = try! Realm()
try! realm.write {
realm.add(NewPerson)
}
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
// let allPeople = realm.objects(person.self)
let SomePersonName = PersonName.text!
if segue.identifier == "PassingSomeInfo" {
if let vc = segue.destination as? AllPersonsInYourDiary {
vc.PeopleData = SomePersonName
}
}
Viewcontroller with the tableView:
var PeopleData: ""
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return PeopleData.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Person1", for: indexPath)
cell.textLabel?.text = self.PeopleData
cell.textLabel?.numberOfLines = 0
cell.textLabel?.font = UIFont.preferredFont(forTextStyle: UIFontTextStyle.headline)
return cell
}
Third viewController (used to store all the person-data):
class person: Object {
#objc dynamic var name = ""
#objc dynamic var answer = ""
#objc dynamic var extraIdentifier = "" }
Thanks!

Answer 1

This question is honestly a little to broad. What you are asking for are several things at once. And if I were to write the implementation for you I wouldn't answer your actual question on what you need to do. What I think you are asking is this:
How do I write and retrieve data from realm.
How do I structure my code for passing data between views.
So my recommendation is this.
Don't pass the data with a segue. Create a class that will access Realm and retrieve the data you need for that view. Name it something like Database, Realm or LocalStorage.
In that class add methods for writing to Realm and retrieving from Realm. How to do that you can find in the Realm documentation: https://realm.io/docs/swift/latest/
In your view that needs to display the entries instantiate your Realm class. Some psuedo code to help you on the way:
class ViewController {
fileprivate let database = LocalStorage()
fileprivate var peopleData: [People]()
viewDidLoad() {
super.viewDidLoad()
database.retrieveData(primaryKey: "extraIdentifier", completionHandler: { entries, err in
if err == nil {
self.peopleData = entries
}
})
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return peopleData.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) ->
UITableViewCell {
let person = self.peopleData[indexPath.item]
let cell = tableView.dequeueReusableCell(withIdentifier: "Person1", for: indexPath)
cell.textLabel?.text = person.name
cell.textLabel?.numberOfLines = 0
cell.textLabel?.font = UIFont.preferredFont(forTextStyle: UIFontTextStyle.headline)
return cell
}
}

Answer 2

After you call
try! realm.write {
realm.add(NewPerson)
}
you already saved on realm so you don't have to pass this on the segue you can retrieve from realm on the next view controller by calling
realm.objects(ofType: NewPerson.self)
This will return an array of NewPerson or you can also search just one with your primary key
realm.object(ofType: NewPerson.self, forPrimaryKey: yourKey)