Swift Global Variables - json

Question

I'm a beginner at Swift so let me know if this doesn't quite make sense, but i have a JSON file that i can access in swift and parse into an array, from there i can get a string from the array and store it in a var. I want to be able to access this variable globally but i'm not sure how to do it.
With the help of another user "rmaddy". I have this code:
struct Games: Decodable {
let videoLink: String
}
class BroadService {
static let sharedInstance = BroadService()
func fetchBroadcasts(completion: #escaping ([Games]?) -> ()) {
let jsonUrlString = "LINK IS HERE."
guard let url = URL(string: jsonUrlString) else {
completion(nil)
return
}
URLSession.shared.dataTask(with: url) { (data, response, err) in
guard let data = data else {
completion(nil)
return
}
do {
let games = try JSONDecoder().decode([Games].self, from: data)
completion(games)
} catch let jsonErr {
print("Error deserializing json:", jsonErr)
completion(nil)
}
}.resume()
}
}
I can then access it in another class from here:
BroadService.sharedInstance.fetchBroadcasts { (games) in
if let games = games {
let game = games[indexPath]
let videoLink = game.videoLink
}
I want to be able to access the contents of "videoLink" globally, without having to use "BroadService.sharedInstance.fetchBroadcasts { (games) in" how would i go about doing this

Answer 1

You shouldn't use global variables, I don't think that's recommended in any language.
Now here you have what looks like a Singleton class (BroadService), that's good because it's a nice solution for what you're looking for.
Next all you need to do is add a property to that class. Let's say videoLink is a string, you can add a string property to BroadService, for example storedVideoLink as an optional String, and the next time you need to obtain that value after you have already fetched it, you can access it like so: BroadService.sharedInstance.storedVideoLink.
One more thing, to have BroadService work properly as a singleton, you should make its init private.
To sum up, here's what I'm suggesting:
class BroadService {
static let sharedInstance = BroadService()
var storedVideoLink: String?
private init() {} // to ensure only this class can init itself
func fetchBroadcasts(completion: #escaping ([Games]?) -> ()) {
// your code here
}
}
// somewhere else in your code:
BroadService.sharedInstance.fetchBroadcasts { (games) in
if let games = games {
let game = games[indexPath]
let videoLink = game.videoLink
BroadService.sharedInstance.storedVideoLink = videoLink
}
}
// now you can access it from anywhere as
// BroadService.sharedInstance.storedVideoLink
This way it all stays cohesive in the same class. You can even add a getter method for storedVideoLink so you don't have to access it directly, and in this method you could state that if the string is nil then you fetch the data, store the link to the string, and then return the string.

Answer 2

You could create a file with a struct called something like Global and create a static var and set that inside your completion block once you have fetched the games.
Here is an example.
struct Global {
static var games:[Any]? = nil
static func setGames(games:[Any]) {
Global.games = games
}
}
Then you fetch the data once upon load of the app or somewhere before you use the Global and set that property:
URLSession.shared.dataTask(with: url) { (data, response, err) in
guard let data = data else {
completion(nil)
return
}
do {
let games = try JSONDecoder().decode([Games].self, from: data)
Global.setGames(games: games)
completion(games)
} catch let jsonErr {
print("Error deserializing json:", jsonErr)
completion(nil)
}
}.resume()
Please note that this will make the Global.games accessible from everywhere but it will also not be a constant so you should be careful not to override it.
This way Global.games will be accessible from anywhere.