Initializer for conditional binding must have Optional type, not 'String'

Question

Here is a fun issue I'm running into after updating to Swift 2.0

The error is on the if let url = URL.absoluteString line

func myFormatCompanyMessageText(attributedString: NSMutableAttributedString) -> NSMutableAttributedString
{
    // Define text font
    attributedString.addAttribute(NSFontAttributeName, value: UIFont(name: "Montserrat-Light", size: 17)!, range: NSMakeRange(0, attributedString.length))

    return attributedString
}

func textView(textView: UITextView, shouldInteractWithURL URL: NSURL, inRange characterRange: NSRange) -> Bool {
    if let url = URL.absoluteString {
        if #available(iOS 8.0, *) {
            VPMainViewController.showCompanyMessageWebView(url)
        }
    }
    return false
}

Did you lookup the documentation for the `absoluteString` method? Does it return an optional?? — Martin R, Sep 24 '15 at 18:21
Just looked it up. No it doesn't return an optional, but `relativeString` is — mosaic6, Sep 24 '15 at 18:27

score 58 · Accepted Answer · answered Sep 24 '15 at 20:23

The compiler is telling you that you can't use an if let because it's totally unnecessary. You don't have any optionals to unwrap: URL is not optional, and the absoluteString property isn't optional either. if let is used exclusively to unwrap optionals. If you want to create a new constant named url, just do it:

func textView(textView: UITextView, shouldInteractWithURL URL: NSURL, inRange characterRange: NSRange) -> Bool {
    let url = URL.absoluteString
    if #available(iOS 8.0, *) {
        VPMainViewController.showCompanyMessageWebView(url)
    }
    return false
}

However, sidenote: having a parameter named URL and a local constant named url is mighty confusing. You might be better off like this:

func textView(textView: UITextView, shouldInteractWithURL URL: NSURL, inRange characterRange: NSRange) -> Bool {
    if #available(iOS 8.0, *) {
        VPMainViewController.showCompanyMessageWebView(URL.absoluteString)
    }
    return false
}

@iPhone6 No, for the same reason you can't use `if let`: because `URL.absoluteString` *always* succeeds. There's nothing to guard against--`absoluteString` is non-optional and will never be `nil`. — andyvn22, Aug 31 '17 at 15:41

Chris Slowik · Answer 2 · 2015-09-24T18:28:53.623

0

absoluteString isn't an optional value, its just a String. You can check if the URL variable is nil

if let url = yourURLVariable {
    // do your textView function
} else {
    // handle nil url
}

edited Sep 24 '15 at 18:28

answered Sep 24 '15 at 18:24

Chris Slowik

2,859
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27

`URL: NSURL` is not an optional, it cannot be nil. – Martin R Sep 24 '15 at 18:26
That's meant to be outside his textView function, will edit for clarity – Chris Slowik Sep 24 '15 at 18:28

score 0 · Answer 3 · answered Nov 15 '21 at 01:21

Note: with reference to the question

Guard or if conditions are used to make sure if the values is not present it should not crash. but the function argument makes sure (URL: NSURL) will come, or any scenario which makes sure the values do come there no need to check with if let or guard statement. That is what compiler is educating developer. try removing the if let or guard statement in such case it should work

Initializer for conditional binding must have Optional type, not 'String'

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