Beginner in Realm Swift - How to instantiate a new Realm in SwiftUI - ios

Question

I have a class DataEntry that I want to store instances of in a Realm database, but i'm having issue instantiating a Realm. Here is my DataEntry class:
class DataEntry: Object {
#objc dynamic var id = 0
#objc dynamic var exercise = ""
#objc dynamic var weightLBS = 0
#objc dynamic var averageBarSpeed = 0
#objc dynamic var topBarSpeed = 0
}
Some context as to what I'll be using it for:
I'd like to have functions to write and delete instances of a DataEntry, but the documentation on that seems fairly simple.
Adding new dataEntry would be done by a user inputing data into a form
Deleting dataEntrys will simply be a button
Planning on reading the data to create graphs to track performance over time
The issue I'm having is instantiating a new Realm, and using the appropriate error handling. I've found a few simpler examples, but they all throw errors so i'm assuming there's something i'm missing. I know you're not supposed to use try!, so I'm wondering, what is a simple way to instantiate a new Realm, so I can then read/write/delete DataEntry's to the Realm Database.
This one gives me multiple "Expected Declaration" errors in lines 1 and 3.
do {
let realm = try Realm()
} catch let error as NSError {
// handle error
}
This one gives me an "Expected Declaration" error on line 1
try {
let realm = try Realm()
} catch {
print(error.localizedDescription)
}
Any additional pointers on how to best set up this would be amazing, wether or not I should have a RealmManager class that would aid in error handling. I've seen in some cases people create extensions of Realm, but this is a little too advanced for me right now.
Background in CS, but brand new to both Swift and Realm for context.
Edit/Update:
Quick clarification, I'm having issues with instantiating a Realm. Not a Realm object. I've updated above to be more clear.
To clarify my question, I'm getting errors for what appears to be good code above, so I assume I have it in the wrong place. I get errors when its inside the DataEntry class, when its inside of a view, and at the top level of a SwiftUI file. Any advice on where I should include the c ode for the instantiation would be great!

Answer 1

I am not sure if this will help but knowing where to put things within a project can sometimes help understand the flow.
So I created a realm project in XCode that writes a person object with the name of Jay to realm when button 0 is clicked. Then when button 1 is clicked, it retrieves that data and prints to console.
There's no error checking here and I am force unwrapping an optional so don't do that in a real app.
import Cocoa
import RealmSwift
class PersonClass: Object {
#Persisted var name = ""
}
class ViewController: NSViewController {
#IBAction func button0Action(_ sender: Any) {
let realm = try! Realm()
let jay = PersonClass()
jay.name = "Jay"
try! realm.write {
realm.add(jay)
}
}
#IBAction func button1Action(_ sender: Any) {
let realm = try! Realm()
let jay = realm.objects(PersonClass.self).where { $0.name == "Jay" }.first!
print(jay.name) //outputs "Jay" to console
}
override func viewDidLoad() {
super.viewDidLoad()
}
}
The project starts with importing RealmSwift and then the Realm object(s) are defined outside of any other classes, so they are at a high level.
Then we have the ViewController with two button actions - as you can see, within each action function, we access realm with
let realm = try! Realm()
and then interact with realm. When that function exits, the realm object is deallocated so it's a safe way to work with Realm and not leave it 'connected'.
Some developers create a singleton or a RealmService class to interact with Realm but singletons can be tricky. I suggest initially going with the pattern shown above (and in the docs).

Answer 2

there has a better way to update and append a new record to Realm in the latest version.
#ObservedResults(Group.self) var groups
$groups.append(Group())
TextField("New name", text: $item.name)
The documentation is here, please take some time to read it.
If it is hard for you, I suggest at least finishing this video by code along with her. LINK