Swift: saving objects into CoreData directly from JSON api rest

Question

I'd need some suggestions about iOS store developing: I need to import data from Rest Api into CoreData of my application in the fastest way possible.

I would like to use Alamofire + ObjectMapper or directly AlamofireObjectMapper to map JSON results into my custom objects model and then save them into CoreData.

I tried to use AlamofireObjectMapper but I don't manage to set Mappable custom NSManagedObject I use to save record into CoreData DB, as explained here

https://github.com/tristanhimmelman/AlamofireObjectMapper

Until now, I used this guide http://code.tutsplus.com/tutorials/core-data-and-swift-subclassing-nsmanagedobject--cms-25116

to create two class

MyCustomObjectClass.swift

MyCustomObjectClass+CoreDataProperties.swift

but, there is a way to set MyCustomObjectClass mappable so that with a simple AlamofireObjectMapper api request I get JSON, create objects and store them directly?

Other possible solutions?

Thank you for help

Solution 1

To parse json to NSManagedObject subclasses, I recommend Groot. It requires a little configuration, but it works great.

I also created a cocoapod called AlamofireCoreData, that wraps Groot into a Alamofire serializer, I think you can use to do exactly what you ask for:

// User is a `NSManagedObject` subclass
Alamofire.request(url)
    .responseInsert(context: context, type: User.self) { response in
        switch response.result {
        case let .success(user):
            // The user object is already inserted in your context!
        case .failure:
            // handle error
        }
}

Hope it can help you.

Solution 2

Api call with core data in Swift 4

import UIKit
import CoreData

class ViewController: UIViewController ,UITableViewDelegate,UITableViewDataSource{

var displayDatasssss = [displyDataClass]()
var context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext

@IBOutlet weak var tableView: UITableView!

override func viewDidLoad() {
    super.viewDidLoad()
    print("hai")

    // Do any additional setup after loading the view, typically from a nib.
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}
func numberOfSections(in tableView: UITableView) -> Int {
    return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return displayDatasssss.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "TableViewCell1") as! TableViewCell1





    let request = NSFetchRequest<NSFetchRequestResult>(entityName: "User")
    cell.label.text = displayDatasssss[indexPath.row].email


    let _:AppDelegate = (UIApplication.shared.delegate as! AppDelegate)
    let context:NSManagedObjectContext = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
    let newUser = NSEntityDescription.insertNewObject(forEntityName: "User", into: context) as NSManagedObject
    newUser.setValue(cell.label.text, forKey: "name")

    do {
        try context.save()
    } catch {}
    print(newUser)
    print("Object Saved.")


    let myStringValue = cell.label.text
    request.predicate = NSPredicate (format: "name == %@", myStringValue!)
    do
    {
        let result = try context.fetch(request)
        if result.count > 0
        {
            let nameData = (result[0] as AnyObject).value(forKey: "name") as! String
            print(nameData)

        }
    }
    catch {
        //handle error
        print(error)
    }

    return cell
}

@IBAction func tap(_ sender: Any) {
    let url = "http://jsonplaceholder.typicode.com/users"
    var request = URLRequest(url: URL(string: url)!)
    request.httpMethod = "GET"
    let configuration = URLSessionConfiguration.default
    let session = URLSession(configuration: configuration, delegate: nil, delegateQueue: OperationQueue.main)
    let task = session.dataTask(with: request){(data, response,error)in
        if (error != nil){
            print("Error")
        }
        else{
            do{
                // Array of Data
                let fetchData = try JSONSerialization.jsonObject(with: data!, options: .mutableLeaves) as! NSArray

                for eachData in fetchData {

                    let eachdataitem = eachData as! [String : Any]
                    let name = eachdataitem["name"]as! String
                    let username = eachdataitem["username"]as! String

                    let email = eachdataitem["email"]as! String
                    self.displayDatasssss.append(displyDataClass(name: name, username: username,email : email))
                }
                self.tableView.reloadData()
            }
            catch{
                print("Error 2")
            }

        }
    }
    task.resume()

    }
}



class displyDataClass {
    var name : String
    var username : String
    var email : String

init(name : String,username : String,email :String) {
    self.name = name
    self.username = username
    self.email = email
   }
}