How to update Array from an API Call in Swift 2.0? [closed] - arrays

Question

Closed. This question needs details or clarity. It is not currently accepting answers.
Want to improve this question? Add details and clarify the problem by editing this post.
Closed 6 years ago.
Improve this question
I'm looking to update an array called 'events' from an api.
Any ideas? Thanks in advance!
var events = [AnyObject]()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
let url : String = "http://api/tickets"
let request : NSMutableURLRequest = NSMutableURLRequest()
request.URL = NSURL(string: url)
request.HTTPMethod = "GET"
NSURLSession.sharedSession().dataTaskWithRequest(request) {
(data : NSData?, response : NSURLResponse?, error : NSError?) in
dispatch_async(dispatch_get_main_queue()) {
// Main thread
self.tableView.reloadData()
}
}
}

Answer 1

So you've got your data back, now you need to convert the data into an object that you can work with. Your event array is an array of AnyObject, which can be cumbersome to work with. Instead, I would recommend that you create a model for these objects.
Since I don't know what your data looks like I'll just make up a model, you'll need to edit this to suit your needs:
struct Ticket {
let id : Int
let description : String
// pass your data object directly into your initializer.
init?(data: [String:AnyObject]) {
guard let itemId = data["id"] as? Int else { return }
guard let itemDesc = data["description"] as? String else { return }
id = itemId
description = itemDesc
}
}
// note: this initializer will fail (by design) if you pass in an
// object that doesn't have the proper requirements. You can exchange the
// guards for if-lets to avoid this behavior
Now, rather than using an array of AnyObject, you work specifically with your modeled item:
// use your model for easy data access
var events = [Ticket]()
Next you update your NSURLSession's closure to create and append your new model object to your array:
NSURLSession.sharedSession().dataTaskWithRequest(request) {
(data : NSData?, response : NSURLResponse?, error : NSError?) in
// make sure you have data
guard let returnedData = data else {
print("no data was returned")
return
}
do {
// convert your object to JSON data... the following code
// may differ depending on how your JSON is formed. However,
// the concept is still the same
// get array of dictionaries
let jsonObject = try NSJSONSerialization.JSONObjectWithData(returnedData, options: .MutableLeaves) as! [[String: AnyObject]]
// loop over your array and create Ticket objects
jsonObject.forEach { item in
var ticket = Ticket(item)
// append your tickets to the array
events.append(ticket)
}
} catch let error {
print(error)
}
dispatch_async(dispatch_get_main_queue()) {
self.tableView.reloadData()
}
}

Answer 2

Let's say, that what is returned to you is Array of tickets and only array of tickets. If you want to get this array, as [AnyObject] you could write:
if let arrayOfAnyObjects = data as? [AnyObject] {
events = arrayOfAnyObjects
}
in this way, you will try to cast data from type NSData to type [AnyObject] if possible. And if it succeed, you will assign it.

Answer 3

You have the right idea. What part don't you understand?
How you parse the response from the server depends on the format of the data. Is it JSON? XML? Some other format?
EDIT:
Ok, you said the data from the server is in JSON format. So inside the completion block of your data request, use NSJSONSerialization to convert your data to a collection object. It looks like Dan gave a pretty complete explanation on how to do that while I was away from my computer.