(XCode 6.3.2, Swift 1.2) I simply want to put the URL of the loaded webpage of the UIWebView into an UITextField. The solutions which I found here doesn't work for me.
Here's my code:
#IBOutlet weak var addressBar: UITextField!
#IBOutlet weak var webView: UIWebView!
//some more code...
func webViewDidFinishLoad(webView : UIWebView) {
self.addressBar.text = (self.webView.request?.URL.absoluteString)!
}
Swift Compiler Error: Value of optional type 'NSURL?' not unwrapped; did you mean to use '!' or '?'?
Any ideas or hints would be very appreciated.
Thanks.
EDIT:
The answer from Airspeed Velocity works for me (see working code below). However I recognized that sometimes the loaded URL isn't correctly written back to the UITextField.
It's reproducible for example on Vimeo.
When I click on a video link on vimeo.com the URL should change to something like: https://vimeo.com/105060039
On mobile Safari this works fine but not on the UIWebView. To the URL "https://vimeo.com/" the video number isn't added.
What I'm doing wrong? Is there an other possibility to get the current URL?
#IBOutlet weak var addressBar: UITextField!
#IBOutlet weak var webView: UIWebView!
//some more code...
func webViewDidFinishLoad(webView: UIWebView) {
addressBar.text = webView.request?.URL?.absoluteString
}
webView.request is optional, so you’re using optional chaining. You just need to do the same with the request’s URL, which is also optional:
self.addressBar.text = self.webView.request?.URL?.absoluteString
Note, there’s no need to force-unwrap this with the ! on the end. This is because self.addressBar.text is itself of type String?.
Swift 3.2
self.addressBar.text = self.webView.request?.url?.absoluteString
Related
This question already has answers here:
What does "Fatal error: Unexpectedly found nil while unwrapping an Optional value" mean?
(16 answers)
Closed 2 years ago.
My Swift program is crashing with a fatal error, saying that "Unexpectedly found nil while implicitly unwrapping an Optional value" even with the GUARD statement . Can anyone help to tell me why, and how do I fix it? The code as follows:
var page: Page? {
didSet{
guard let unwrappedPage = page else { return }
NameLabel.text = unwrappedPage.dishName
Image.image = UIImage(named: unwrappedPage.imageName)
contentText.text = unwrappedPage.ingredient
contentText.text = unwrappedPage.instruction
}
}
The issue is likely that the outlets have not been hooked up by the time you set page, and if these outlets are implicitly unwrapped optionals (with the ! after the type name, e.g. UILabel!), that will result in the error you describe. This problem will manifest itself if, for example, you set page before the view controller in question has been presented and all of the outlets have been hooked up.
So, I’d recommend:
Use optional chaining with your #IBOutlet references so it won’t fail if the outlets haven’t been hooked up yet.
Go ahead and keep your didSet observer on page, if you want, but make sure you also update the controls in viewDidLoad in case page was set before the outlets were hooked up.
For example:
#IBOutlet weak var nameLabel: UILabel!
#IBOutlet weak var imageView: UILabel!
#IBOutlet weak var ingredientLabel: UILabel!
#IBOutlet weak var instructionLabel: UILabel!
var page: Page? { didSet { updateControls(for: page) } }
override func viewDidLoad() {
super.viewDidLoad()
updateControls(for: page)
}
func updateControls(for page: Page?) {
nameLabel?.text = page?.dishName
imageView?.image = page.flatMap { UIImage(named: $0) }
ingredientLabel?.text = page?.ingredient
instructionLabel?.text = page?.instruction
}
Note, you only need this didSet observer if the page might be set (again) after the view has been presented. If not, the didSet observer is not needed.
The use case of the app I am developing is I will have login view at the initial. When user logs in with valid credentials, the user should see another view saying welcome user. I am totally beginner and I don't know much more about xcode. I see the screen navigation from storyboard but I have already done many things in xib.
Here is what I have done
SafariExtensionViewController.swift
import SafariServices
class SafariExtensionViewController: SFSafariExtensionViewController {
#IBOutlet weak var passwordMessage: NSTextField!
#IBOutlet weak var emailMessage: NSTextField!
#IBOutlet weak var message: NSTextField!
#IBOutlet weak var email: NSTextField!
#IBOutlet weak var password: NSSecureTextField!
static let shared = SafariExtensionViewController()
override func viewDidLoad() {
self.preferredContentSize = NSSize(width: 300, height: 250)
message.stringValue = ""
emailMessage.stringValue = ""
passwordMessage.stringValue = ""
}
#IBAction func userLogin(_ sender: Any) {
let providedEmailAddress = email.stringValue
let providedPassword = password.stringValue
let isEmailAddressValid = isValidEmailAddress(emailAddressString: providedEmailAddress)
self.message.stringValue = ""
emailMessage.stringValue = ""
passwordMessage.stringValue = ""
if isEmailAddressValid && providedPassword.count > 0 {
// api call is done here
// when success should show another screen
} else {
emailMessage.textColor = NSColor.red
emailMessage.stringValue = "Invalid Email"
}
}
}
here is the screenshot of xib.
Technology used
swift 4
xcode 9
not IOS its mainly for app extension
UPDATE
I am not using storyboard and also it's not IOS. I am using xib and from macos project I am trying to develop app extension which will be shown in browser as an extension.
A lot of time left from question posted, but it can be helpful for others as me (I'm porting safari legacy extension to safari app extension) and find the way with use of NSTabView with tabless style:
The use is:
Ensure to add NSObject in your storyboard from the Library:
And connect with the tabview from Outlet:
I'm rather newbie in Cocoa and Swift and if anyone knows more beautiful solution for routing, please share it with others!
I am trying to programmatically switch the whole screen to grayscale mode, but the CGDisplayForceToGray function has disappeared in Swift 4(?). Is there another function or method to replicate the CGDisplayForceToGray effect or has Apple deprecated functions of this kind entirely? Thank you.
Edit: For example, the code for Desaturate has a function called CGDisplayForceToGray() which turns the whole screen into grayscale mode, in the same way, that the "Use Grayscale" checkbox in the Accessibility Preferences turns the screen into grayscale. See below (this code is from Desaturate):
import Cocoa
import Carbon
#NSApplicationMain
class AppDelegate: NSObject, NSApplicationDelegate {
#IBOutlet weak var statusMenu: NSMenu!
var grayscaleStatus = false;
var preferencesWindow: PreferencesWindow!
// For MASShortcut
let callback = {}
let defaultsKey = "global_shortcut"
#IBOutlet weak var window: NSWindow!
#IBAction func quitAction(sender: AnyObject) {
NSApplication.sharedApplication().terminate(self)
}
#IBAction func toggleAction(sender: AnyObject) {
self.toggleGrayscale()
}
func toggleGrayscale() {
grayscaleStatus = !grayscaleStatus
CGDisplayForceToGray(grayscaleStatus)
}
However, when I tried to use the CGDisplayForceToGray() function myself, I get the Use of unresolved identifier error. My guess is that the CGDisplayForceToGray() function was deleted or isn't functional anymore, but I was wondering if there were other alternatives to this function that don't use AppleScript.
Edit: Resolved.
Why am I getting a 'nil' error/UILabel during my second pass thru the table cell listing iteration?
1) Inside cell
2) Inside cell
fatal error: unexpectedly found nil while unwrapping an Optional value
(lldb) po cell?.contentView.viewWithTag(TitleLabelTag)
nil
Here I link the elements in the code; and register the cell:
class DiaryTableViewCell: UITableViewCell {
#IBOutlet weak var TitleLabel: UILabel!
#IBOutlet weak var SubTitleLabel: UILabel!
#IBOutlet weak var leftImageView: UIImageView!
#IBOutlet weak var rightImageView: UIImageView!
}
class DiaryTableViewController: UITableViewController {
let kCellIdentifier = "DiaryCell"
var cellNib:UINib?
var diaryCell:DiaryTableViewCell?
var objects = NSMutableArray() //...global var.
override func viewDidLoad() {
self.title = "My Diary"
cellNib = UINib(nibName: "TableViewCells", bundle: nil)
tableView.registerClass(DiaryTableViewCell.self, forCellReuseIdentifier: kCellIdentifier)
}
...
Yet I'm getting the runtime error here:
Here's what I get in the console:
1) Inside cell
fatal error: unexpectedly found nil while unwrapping an Optional value
(lldb) po cell!.TitleLabel
nil
What's missing here?
It's a pretty bad idea to select a view with a tag. It's a much better idea to subclass your UITableViewCell and give it a property to access the elements.
If you are creating static cells and loading you need to create an IBoutlet for them in your .h correctly.
Moreover remove line
tableView.registerClass(...) statement from your code. Look at this link might help and is very similar except its for collectionview. -
Why is UICollectionViewCell's outlet nil?
1) I moved the cell registration to the viewDidLoad().
2) I forgot to place the '?' after the TitleLabel & SubTitleLabel; to notify the compiler that these labels could be nil.
I don't see the altered cell yet (empty rows); but I'm not getting runtime errors.
Unfortunately I merely cured the symptom; not the cause. I'm still getting nil UILabels.
...working on revision and cleaner code.
Using Swift only, here's my code in AppDelegate.swift:
import Cocoa
class AppDelegate: NSObject, NSApplicationDelegate {
#IBOutlet var window: NSWindow
#IBOutlet var textField: NSTextView
#IBAction func displaySomeText(AnyObject) {
textField.insertText("A string...")
}
func applicationDidFinishLaunching(aNotification: NSNotification?) {
// Insert code here to initialize your application
}
func applicationWillTerminate(aNotification: NSNotification?) {
// Insert code here to tear down your application
}
}
In the interface builder, I have an object hooked up to receive input from a button, then the output goes to a text view. I'm trying to get the text view to populate with some text when I hit the button.
I tried this with a text field as well, and didn't get the error, but got a "dong" error sound and it didn't do anything else. In Objective-C, you had to use the (assign) parameter to get this to work from what I understand.
What am I doing wrong?
You cannot store a weak reference to an NSTextView due to historical issues with Cocoa and AppKit. See details in the Clang documentation. NSTextView is marked as NS_AUTOMATED_REFCOUNT_WEAK_UNAVAILABLE in NSTextView.h, there are also a few other classes to lookout.
Have you tried a Swift unowned reference instead of weak, which is kind of like Objective-C's assign (what you'd use for an NSTextView outlet in Objective-C)?
Use #IBOutlet var scrollView: NSScrollView instead of #IBOutlet var textField: NSTextView.
Then create a property returns documentView in scrollView.
import Cocoa
class AppDelegate: NSObject, NSApplicationDelegate {
#IBOutlet var window: NSWindow
#IBOutlet var scrollView: NSScrollView
var textField: NSTextView {
get {
return scrollView.contentView.documentView as NSTextView
}
}
#IBAction func displaySomeText(AnyObject) {
textField.insertText("A string...")
}
func applicationDidFinishLaunching(aNotification: NSNotification?) {
// Insert code here to initialize your application
}
func applicationWillTerminate(aNotification: NSNotification?) {
// Insert code here to tear down your application
}
}
I have tried to replicate what you described. I have created a new OS X app using Xcode 6 beta 7. I have dropped a button and text view in the main form.
I think your problem is that the connection to the Text View object is not correct for some reason. To make things easier, I've connected the objects using control-drag, which adds the required code automatically. So first I've connected the Text View. To do this click on the text view object until Text View is selected. When I do this in my version of Xcode, the first time I click on the object, Bordered Scroll View is selected. Clicking on it again then selects Clip View. Finally, clicking on it again selects Text View. Now I control-drag from the object to the AppDelegate.swift code (It helps to display the Assistant Editor so that you have your form UI and code side-by-side).
By doing this I get this little window:
Notice that the type is NSTextView and the storage is Weak. I've only had to add the name and click Connect. This adds the following code in AppDelegate.swift:
#IBOutlet var textField: NSTextView!
The code is almost exactly like the one you have, except for the ! at the end of the line, which forces to unwrap the value of textField.
Just with that, the code as you have it in your question should work.
The other thing I would suggest is not to use insertText. According to Apple's documentation for NSTextView.insertText:
This method is the entry point for inserting text typed by the user
and is generally not suitable for other purposes. Programmatic
modification of the text is best done by operating on the text storage
directly.
As far as I understand this, programmatic modification of the text by operating on the text storage directly means dealing with NSText, which NSTextView inherits from. So instead, use NSText.string. This is how the click button action looks in my code:
#IBAction func displaySomeText(sender: NSButton) {
// If you want to add a new 'A string... ' every time you click the button
textField.string! += "A string... "
// otherwise just use
//textField.string = "A string..."
}
I have added the Button Action in the same way as I've added the Text View Outlet, by control-dragging, and, in this case, selecting NSButton as the sender, instead of leaving the default AnyObject.
#IBOutlet automatically makes a property weak IIRC, but weak doesn't automatically make a property optional. But it is required that a weak property be made optional, as the property could at any time be deallocated and made nil. So you have to declare your #IBOutlets as optional.
import Cocoa
class AppDelegate: NSObject, NSApplicationDelegate {
#IBOutlet var window: NSWindow? // Optional
#IBOutlet var textField: NSTextView?
#IBAction func displaySomeText(AnyObject) {
textField?.insertText("A string...") // Only call the method if the object exists
}
func applicationDidFinishLaunching(aNotification: NSNotification?) {
// Insert code here to initialize your application
}
func applicationWillTerminate(aNotification: NSNotification?) {
// Insert code here to tear down your application
}
}
Does the "dong" error suggest a responder chain problem? What if you call becomeFirstResponder on the text field before inserting the text?
To create a weak reference user the weak keyword:
example:
#IBOutlet weak var myView: UIView
In your case
#IBOutlet weak var textField: NSTextView