Populate UItableview with parse and url - ios

Question

What is the best practice for populating a tableview from a URL that takes user data from parse in the URL string. Currently the code is working, but it could result in an error if the parse user data isn't loaded before the URL request is run. This will cause the table to not load (not safe code)
The user class in parse has a key of "teamNumber" which plugs in to the URL to fetch a string of the page source. From there the string is manipulated to create an array that is displayed as the table view.
Here is the code (edited to take out the string manipulation):
override func viewDidLoad() {
super.viewDidLoad()
//To the internet to grab the "leagueNumber" of a user to input into the attemptedUrl string
let leagueNumber = PFUser.currentUser()!["leagueNumber"] as? String
//Plug in the league number from parse into URL string
let attemptedUrl = NSURL(string: "http://someURL.leagueapps.com/leagues/\(leagueNumber!)/teams")
if let url = attemptedUrl {
let task = NSURLSession.sharedSession().dataTaskWithURL(url) { (data, response, error) -> Void in
if let urlContent = data {
let webContent = NSString(data: urlContent, encoding: NSUTF8StringEncoding)
//Manipulate string to get the team information
//Ends up with array [team1, team2, team3, team4] to populate the tableview
}
} else {
print("URL could not connect")
}
//Close internet session
dispatch_async(dispatch_get_main_queue(), { () -> Void in
self.tableView.reloadData()
})
}
task.resume()
} else {
print("Fail")
}
}
Is there a safer way to implement this code?

Answer 1

I supposed you could make it "safer" by fetching the full user object from parse with a query, and then forming your URL with that result:
var query = PFUser.query
var currentUser = PFUser.currentUser()
query.whereKey("username", equalTo: currentUser.username)
query.getFirstObjectInBackgroundWithBlock {
(object: PFObject?, error: NSError?) -> Void in
if error != nil || object == nil {
println("The getFirstObject request failed.")
} else {
// The find succeeded.
leagueNumber = object["leagueNumber"] as! String!
println("Successfully retrieved the object.")
}
}