Why have a Array Empty and Error in swift4?

Question

I've spent a few hours trying to get a fetch to work in my film sheet. I need to open film's View of my colectionview Items. I could follow different guide and post but it always give me an empty array. I'm newbie, sorry for my question but I need your help.

Here's my code:

var taskArrayScheda : NewFilm?

override func viewDidLoad() {
super.viewDidLoad()

self.fetchData()

if(self.taskArrayScheda != nil) {

let schedaOk = taskArrayScheda
mostraDatiNellaScheda(schedaOk!)

} else { print("errore array vuoto") }


}

func mostraDatiNellaScheda(_ sched:NewFilm) {

// get title
titoloScheda.text = sched.titolo
}

func fetchData() {
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext


let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "NewFilm")

do {
taskArrayScheda = try context.fetch(NewAnime.fetchRequest())
💥ERROR ::::: Cannot assign value of type '[Any]' to type 'NewFilm?'

} catch {
print(error)
}
}

Unrelated but why do you create two different fetch requests? By the way the used one doesn't match the type of the property (beside the array issue). — vadian
– vadian, Commented Feb 27, 2019 at 16:40

meaning-matters · Accepted Answer · 2019-02-27 16:41:33Z

1

The fetch() returns an array. But currently you assign the fetch() result to the single object var taskArrayScheda.

You'll need something like:

var taskArrayScheda: [NewFilm]?

Then you should do:

taskArrayScheda = try context.fetch(NewAnime.fetchRequest()) as? [NewFilm]

I assume here that NewAnime is a subclass of NewFilm, which seems to make sense looking at these two class names.

edited Feb 27, 2019 at 16:41

answered Feb 27, 2019 at 16:38

meaning-matters

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5 Comments

peg101 Over a year ago

so I can change with code var taskArray = [NewFilm]()

meaning-matters Over a year ago

@peg101 Yes, if you want to define a NewAnime array variable and set it to an empty array at the same time.

peg101 Over a year ago

ok now I have error in this Func func mostraDatiNellaScheda(_ sched:[NewFilm]) { titoloScheda.text = sched.titolo Value of type '[NewAnime]' has no member 'titolo' }

peg101 Over a year ago

NewFilm is my Entity

meaning-matters Over a year ago

@peg101 shed is an array of NewFilm. So you must select one of the elements with something like if let film = sched.first { titoloScheda.text = film.titolo }

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