Calling/messaging code crashing? - ios

Question

I have buttons that when pressed, will call/message a number from an array. i.e. button1 will call the number at index 0 of the array, button2 at index 1, etc.. For some reason whenever the number from the array contains a format other than xxx-xxx-xxx it crashes (i.e. (xxx) xxx-xxx). And yet, the log gives me the following error even though the array isn't nil:
Anyone know why this is happening?
Here is the code for everything:
import UIKit
import AddressBook
var contactInfo: [String] = []
[...]
override func viewDidLoad() {
super.viewDidLoad()
//this is the function that grabs the array from an app group
setUpCallMessageButtons()
[...]
callButton1.addTarget(self, action: "call:", forControlEvents: UIControlEvents.TouchUpInside)
}
func call(sender:UIButton!)
{
if (sender == callButton1) {
println("\(contactInfo)")
var url:NSURL? = NSURL(string: "tel:\(contactInfo[0])")
self.extensionContext?.openURL(url!, completionHandler:{(success: Bool) -> Void in
})
}
}
func setUpCallMessageButtons(){
let appGroupID = "**redacted**"
let defaults = NSUserDefaults(suiteName: appGroupID)
contactInfo = (defaults!.objectForKey("contactInfo") as! [String])
println("\(contactInfo)")
//This is gives the log down below. As you can see, none are nil.
}
Buttons 1,2 and 5 work while 3 and 4 always crash.

Answer 1

My guess is that if the phone number isn't formatted correctly, the call to convert it to an NSURL is failing and returning nil.
You probably need to wrap your call to openURL in an optional binding ("if let") block:
var url:NSURL? = NSURL(string: "tel:\(contactInfo[0])")
if let url = url
{
self.extensionContext?.openURL(url!,
completionHandler:
{
(success: Bool) -> Void in
}
}
else
{
println("Phone number \(contactInfo[0]) is not in a valid format")
}
You might want to strip away parenthesis from your phone number before trying to create your URL. A simple way would be to use the NSString method stringByReplacingOccurrencesOfString:withString:.

Answer 2

Here's a little storyboard - which shows you where the nil is coming from
Unexpectedly found nil means there is a variable which is expected to be non-nil but at run time was nil
This is the line of code that is causing the issue
self.extensionContext?.openURL(url!, completionHandler:{(success: Bool)
It expects url to be non-nil (i.e. the !) but it is definitely nil (see image)

Answer 3

If this data comes from the user or from the internet, you might want a method to strip away all non-numeric characters. Something like this (from a working playground I just banged out) :
import UIKit
func digitsOnly(#fromString: String) -> String
{
var workString = NSMutableString(string: fromString)
let digitsSet = NSCharacterSet.decimalDigitCharacterSet()
var index: Int
for index = count(fromString)-1; index>=0; index--
{
if !digitsSet.characterIsMember(workString.characterAtIndex(index))
{
workString.deleteCharactersInRange(NSRange(location:index, length:1))
}
}
return workString as String
}
let testString = "[phone]"
let result = digitsOnly(fromString:testString)
println("digitsOnly(\"\(testString)\") = \"\(result)\" ")
This displays:
digitsOnly("[phone]") = "5551112222"
Edit:
Or alternately a more Swift-like version of the same function:
func digitsOnly(#fromString: String) -> String
{
var result = String()
let digitsSet = NSCharacterSet.decimalDigitCharacterSet()
for char in fromString
{
if digitsSet.characterIsMember(char as unichar)
result += char
}
}
EDIT #2:
You can increase the set of characters that is left in place by changing the character set you use. Replace the line
let digitsSet = NSCharacterSet.decimalDigitCharacterSet()
With
let digitsSet = NSCharacterSet(charactersInString: "0123456789+-")
To preserve "+" signs and dashes. (Edit the string to include the characters you need.)