how to implement json in realm swift - swift

Question

I have a dictionary in json format. I want to show it with a table in my app(about 1000 cells) and also save it to realm database. I am new to database can anyone please tell me how to implement this? Should I try to convert the format outside the app or load the json when it is used?
My dictionary looks like this..
[
{
"id":0,
"book":1,
"lesson":1,
"kanji":"\u4e2d\u56fd\u4eba"
} {
"id":1,
"book":1,
"lesson":1,
"kanji":"\u65e5\u672c\u4eba"
},
...
]

Answer 1

First of all, you will need to install 2 pods:
pod 'SwiftyJSON' #great for handling JSON
pod 'RealmSwift' #Realm database
You will need to create the object that will be able to be saved in Realm. I suppose your object is some type of course or something similar. You can rename it per your needs:
import Foundation
import RealmSwift
import SwiftyJSON
class Course: Object {
#objc dynamic var id = 0
#objc dynamic var book = 0
#objc dynamic var lesson = 0
#objc dynamic var kanji = ""
override static func primaryKey() -> String? { //you need this in case you will want to update this object in Realm
return "id"
}
convenience init(courseJson: JSON) {
self.id = courseJson["id"].intValue
self.book = courseJson["book"].intValue
self.lesson = courseJson["lesson"].intValue
self.kanji = courseJson["kanji"].stringValue
}
}
Now, at the place where you get your json from the server, you need to do this:
var courses = [Course]()
let jsonArray = JSON(dataFromServer).arrayValue
for courseJson in jsonArray {
let course = Course(courseJson: courseJson)
courses.append(course)
}
//Now, you need to save these objects in Realm:
let realm = try! Realm()
try! realm.write {
realm.add(courses, update: true)
}
In the viewDidLoad method of the view controller where you want to show the data, you need to fetch all your Course objects from Realm, add them to an array and show data in the tableView/collectionView:
import UIKit
import RealmSwift
class PresentingCoursesVC: UIViewController {
//MARK: IBOutlets
#IBOutlet weak var tableView: UITableView!
//MARK: Properties
var courses = Results<Course>?
//MARK: Lifecycles
override func viewDidLoad() {
super.viewDidLoad()
getCourses()
}
//MARK: Private functions
private func getCourses() {
let realm = try! Realm()
courses = realm.objects(Course.self).sorted(byKeyPath: "id", ascending: true)
tableView.reloadData()
}
}
//MARK: TableView Datasource
extension PresentingCoursesVC: UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return courses?.count ?? 0
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "MyCustomCell") as! MyCustomCell
let course = courses[indexPath.row]
cell.setupCell(course: course)
return cell
}
}
I hope my answer was helpful!

Answer 2

class Book: Object {
#objc dynamic var id = 0
#objc dynamic var book = 0
#objc dynamic var lesson = 0
#objc dynamic var kanji = ""
}
class MyDic: Object {
var yourKeyOfDic = List<Book>()
}
Now map your dic with MyDic class object and then add that object in realm by following code,
let realm = try! Realm()
try! realm.write {
realm.add(yourDicObject)
}