swift - JSON to NSManagedObject - ios

Question

I have a JSON data which I want to map to CoreData when my tableview loaded at first launch.
I found a way to do it in cellForRowAtIndexPath, but this way I can only save the data to CoreData when the cell is displayed.
I want to do it once for all cells.
var yazarMakaleListesi: [JSON]? = []
var authorList = [AuthorList]() // My CoreData
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell = tableView.dequeueReusableCellWithIdentifier("YazarCell") as! YazarTableViewCell
cell.yazar = self.yazarMakaleListesi?[indexPath.row]
cell.yazar = self.yazarMakaleListesi?[indexPath.row]
let authorName = self.yazarMakaleListesi?[indexPath.row]["author_name"].string
let authorID = self.yazarMakaleListesi?[indexPath.row]["author_id"].int
let authorImage = self.yazarMakaleListesi?[indexPath.row]["author_image"].string
let newspaperID = self.yazarMakaleListesi?[indexPath.row]["newspaper_id"].string
let newspaperName = self.yazarMakaleListesi?[indexPath.row]["newspaper"].string
let newsPaperImage = self.yazarMakaleListesi?[indexPath.row]["author_image"].string
let articleEntity = NSEntityDescription.entityForName("AuthorList", inManagedObjectContext: self.context!)
let newAuthor = AuthorList(entity: articleEntity!, insertIntoManagedObjectContext: self.context!)
newAuthor.authorName = authorName!
newAuthor.authorImage = authorImage!
newAuthor.newspaperName = newspaperName!
newAuthor.newsPaperImage = newsPaperImage!
newAuthor.authorID = authorID!
var saveError: NSError?
self.context!.save(&saveError)
if let _error = saveError {
println("\(_error.localizedDescription)")
} else {
println("Author Saved!")
}
var error: NSError?
let request = NSFetchRequest(entityName: "AuthorList")
let results = self.context!.executeFetchRequest(request, error: &error) as! [AuthorList]
return cell
}
I get the JSON data here:
func loadYazar(){
if (gazeteid != nil){
let url = "http:myapi.com" + String(gazeteid)
Alamofire.request(.GET, url).responseJSON { (Request, response, json, error) -> Void in
if (json != nil){
var jsonObj = JSON(json!)
if let data = jsonObj["authors"].arrayValue as [JSON]?{
self.yazarMakaleListesi = data
self.tableView.reloadData()
}
}
}
}
}
EDIT : I get my jsonresponse here, implemented # thefredelement's recommendation.
But I get " 'JSON' does not have a member named 'valueForKey'" from line:
newFakeCoreDataObject.authorName = jsonResult.valueForKey("authorName") as! String
Alamofire.request(.GET, url).responseJSON { (Request, response, json, error) -> Void in
if (json != nil){
var jsonObj = JSON(json!)
if let jsonResults = jsonObj["authors"].arrayValue as [JSON]?{
self.yazarMakaleListesi = jsonResults
var error : NSError?
for jsonResult in jsonResults {
let newFakeCoreDataObject = FakeCoreDataObject()
newFakeCoreDataObject.authorName = jsonResult.valueForKey("authorName") as! String
self.context!.save(&error)
}
self.tableView.reloadData()
}
}

Answer 1

I would highly suggest taking that work out of cellForRowAtIndex path and making a separate function that will iterate through your JSON results and save them each, then load the data from core data as a custom object and put that object into an instance array, then use that array for your table data.
Edit: I wouldn't use this code exactly obviously, it's just an example of what I was trying to explain.
import UIKit
import CoreData
class FakeCoreDataObject : NSObject {
// this would really be your NSManagedObject subclass
var authorName = ""
var authorImage = NSData()
var newspaperName = ""
var newspaperImage = NSData()
var authorId = 0 as NSNumber
}
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
var myEntries = [FakeCoreDataObject]()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
fetchJson()
prepareTableData()
}
func fetchJson() {
let appDel = UIApplication.sharedApplication().delegate as! AppDelegate
let context = appDel.managedObjectContext!
var error : NSError?
// Get your json reuslts like you are already
var jsonResults = [AnyObject]() // just for an example
for jsonResult in jsonResults {
let newFakeCoreDataObject = FakeCoreDataObject()
newFakeCoreDataObject.authorName = jsonResult.valueForKey("authorName") as! String
// etc
context.save(&error)
// save whatever else you want for other entities, etc, if you need track out of scope you can do that and then save after the loop
}
}
func prepareTableData() {
let appDel = UIApplication.sharedApplication().delegate as! AppDelegate
let context = appDel.managedObjectContext!
var error : NSError?
let fetchTableDataRequest = NSFetchRequest(entityName: "whateverItIsCalled")
fetchTableDataRequest.returnsObjectsAsFaults = false
myEntries = context.executeFetchRequest(fetchTableDataRequest, error: &error) as! [FakeCoreDataObject]
// If you need to do this often, reload the table data here too and you can call it from notifications, etc.
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return myEntries.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
// cell stuff you already have but just use the array
// just a tip to set set values to "" or nil if you're creating a big table so you don't get duplciate data while scrolling
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}

Answer 2

you should parse the json you receive inside responseJSON:
let jsonObj = NSJSONSerialization.JSONObjectWithData(json, options:NSJSONReadingOptions(rawValue: 0), error: &err) as! NSDictionary
callback(jsonObj as! Dictionary<String, AnyObject>, nil)
var recs:NSArray = jsonObj.objectForKey("authors") as! NSArray
var ct:Int = 0
for item in recs{
var dict:NSDictionary = item as! NSDictionary
// use self.yazarMakaleListesi[ct] here
// process into the dict "author_name" , "author_id", etc
// increment ct
}
self.tableView.reloadData()