Populate array of custom classes from two different network requests - ios

Question

In my Swift iOS project, I am trying to populate an array of custom class objects using JSON data retrieved with Alamofire and parsed with SwiftyJSON. My problem, though, is combining the results of two different network request and then populating a UITableView with the resulting array.
My custom class is implemented:
class teamItem: Printable {
var name: String?
var number: String?
init(sqljson: JSON, nallenjson: JSON, numinjson: Int) {
if let n = sqljson[numinjson, "team_num"].string! as String! {
self.number = n
}
if let name = nallenjson["result",0,"team_name"].string! as String! {
self.name = name
}
}
var description: String {
return "Number: \(number) Name: \(name)"
}
}
Here is my viewDidLoad():
override func viewDidLoad() {
super.viewDidLoad()
tableView.dataSource = self
refresh() {
() -> Void in
self.tableView(self.tableView, numberOfRowsInSection: self.teamsArr.count)
self.tableView.reloadData()
for item in self.teamsArr {
println(item)
}
return
}
self.tableView.reloadData()
}
which goes to the refresh() method:
func refresh(completionHandler: (() -> Void)) {
populateArray(completionHandler)
}
and finally, populateArray():
func populateArray(completionHandler: (() -> Void)) {
SqlHelper.getData("http://cnidarian1.net16.net/select_team.php", params: ["team_num":"ALL"]) {
(result: NSData) in
let jsonObject : AnyObject! = NSJSONSerialization.JSONObjectWithData(result, options: NSJSONReadingOptions.MutableContainers, error: nil)
let json = JSON(jsonObject)
self.json1 = json
println(json.count)
for var i = 0; i < json.count; ++i {
var teamnum = json[i,"team_num"].string!
NSLog(teamnum)
Alamofire.request(.GET, "http://api.vex.us.nallen.me/get_teams", parameters: ["team": teamnum])
.responseJSON { (req, res, json, err) in
let json = JSON(json!)
self.json2 = json
self.teamsArr.append(teamItem(sqljson: self.json1, nallenjson: self.json2, numinjson: i))
}
}
completionHandler()
}
}
the first problem I had was that i in the for loop reached 3 and caused errors when I thought it really shouldn't because that JSON array only contains 3 entries. My other main problem was that the table view would be empty until I manually triggered reloadData() with a reload button in my UI, and even then there were problems with the data in the tables.
really appreciate any assistance, as I am very new to iOS and Swift and dealing with Alamofire's asynchronous calls really confused me. The code I have been writing has grown so large and generated so many little errors, I thought there would probably be a better way of achieving my goal. Sorry for the long-winded question, and thanks in advance for any responses!

Answer 1

The Alamofire request returns immediately and in parallel executes the closure, which will take some time to complete. Your completion handler is called right after the Alamofire returns, but the data aren't yet available. You need to call it from within the Alamofire closure - this ensures that it is called after the data became available.