Swift 2.2: fatal error: unexpectedly found nil while unwrapping an Optional value

0
votes

Sorry for my dummy question but I'm new on Swift development, I have a project on Swift 1.1 which was working properly but after upgrading to Xcode to 7.3.1 (With Xcode 2.2.1) my project is built successfully but I'm getting an error while running it (on the let request line) with the following code:

// Send HTTP GET Request

    let request = NSURLRequest(URL: NSURL(string: "http://11.22.33.44:8080/MySRV/login?email=\(emailField.text)&password=\(pwdField.text)")!)

    NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue(), completionHandler:{
        (response: NSURLResponse?, data: NSData?, error: NSError?)-> Void in

        print("response \(response?.description)")

the error is:

Thread 1: EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0) fatal error: unexpectedly found nil while unwrapping an Optional value

I can imagine that my let request is nil but I don't know how to solve it.

Thanks for your help.

2
iosxcode
You solve it by debugging. First find out what is nil, is it request? If so then why might it be nil. Might it be that emailField.text is nil? if so why might that be nil, where and how does it get set? Or maybe its because pwdField.text is nil, if so how might that be nil? Where is it getting set? Why does it not have a value and so on and so on. These are all question you can ask yourself and can answer yourself if you try. That is debugging. – Gruntcakes
Three unrelated observations: 1. NSURLConnection is now deprecated, so you should now use NSURLSession (or in Swift 3, URLSession). 2. You should not include a password in a URL. You should build a POST request and include the two parameters in the body of the request. I'm assuming your eventual server will employ HTTPS, but regardless it is recommended to not put sensitive information in the URL as some old proxy servers may capture that. 3. You should be percent escaping the email address and password. This will fail if they contained reserved characters (notably + or &). – Rob
Thanks Rob, I will use NSURLSession then. As I told you I 'm a beginner in swift so any advice are more than welcome – tiamat

2 Answers

3
votes

From here it looks like your unwrapping an optional value that is nil. Try this:

    if let url: NSURL = NSURL(string: "http://11.22.33.44:8080/MySRV/login?email=\(emailField.text)&password=\(pwdField.text)") {
        let request = NSURLRequest(URL: url)
        // Do asynchronous request here
    } else {
        // NSURL is incorrect
    }

This is how you can safely unwrap an optional value in Swift. You might also want to check if the emailField.text and pwdField.text are also not nil values. It would look something like this:

     if let email: String = emailField.text {
        // Text is not nil
     } else {
        // UITextField text is nil!
     }

In the else blocks you can add logic to notify the user to input text or to perform some other action. You can read more about this here.

Hope this helps!

0
votes

The problem is likely a result of the fact that the text properties of your two text fields are optionals, and thus is being added to your URL as Optional("[email protected]") and Optional("password"), and thus the attempt to build the URL is failing.

You can do something like:

guard let email = emailField.text else {
    print("email is `nil`")
    return
}

guard let password = pwdField.text else {
    print("password is `nil`")
    return
}

let request = NSURLRequest(URL: NSURL(string: "http://11.22.33.44:8080/MySRV/login?email=\(email)&password=\(password)")!)