So i have a UITextField named apiTextField and a function of the saveButton :
func saveButton(_ sender: Any) {
}
I want when the user writes to the UITextField and press the saveButton that text the user wrote be passed to a variable which is called var baseURL:String? in another class.
I didn't find anything related to UITextField so i decided to make this question, another similar one is 10 years old!.
var anotherClass = AnotherClass()
func saveButton(_ sender: Any) {
guard let text = apiTextField.text, !text.isEmpty else { return }
anotherClass.baseURL = text
}
Is that what you are looking for?
Related
I've created a variable in one IBAction which saves a string, and I want to be able to call that variable in another IBAction in the same file. How do I define the variable globally so that the other IBAction can call it?
The variable message comes from a UIAlertController output, which appears when pressing a button on the View Controller.
#IBAction func EditMessage(_ sender: Any) {
let message = Message(message: text)
}
#IBAction func PostArticle(_ sender: Any) {
let parameters = ["title": "subheading", "content": "\(message)"]
}
Trying to call the message variable from the other IBAction will only give the error:
Use of unresolved identifier 'message'
class MyViewController : UIViewController {
var message = ""
#IBAction func EditMessage(_ sender: Any) {
message = Message(message: text)
}
#IBAction func PostArticle(_ sender: Any) {
let parameters = ["title": "subheading", "content": "\(message)"]
}
}
Hope it Helps.
Make your message variable be accessible to the two IBActions.
Your Message function should return a string
Message(message: String) -> String {
// Do something here
return "sample"
}
Read Swift Function
I have to create an app, with a label, a text box and a button, that will take the text that the user inputs and test if it is a palindrome and true a yes or no. It requires that I write the palindrome function in another file and call it when the button is press. The return from the function will also have to be displayed in the label field.
I have written and tested out the function but I don't know how connect it with the 3 objects on my app. They didn't teach how to do this yet in the course and googling the terms "linking text field to function in swift" only confused me more.
How should I go about learning how to do this? What terms should I search for to learn about this? I also included my palindrome funciton as reference.
func isPalindrome(word: String) -> Bool{
let word2 = word
let reversedWord = String(word.reversed())
if word2 == reversedWord {
return true
} else {
return false
}
}
isPalindrome(word: "racecar")
I presume that you know how to connect elements from storyboard to your view controller.
Link your textfield to your ViewController
#IBOutlet weak var textfield: UITextField!
then your button.
let text = textfield.text
#IBAction func checkBtn(_ sender: Any) {
isPalindrome(word: text!)
}
func isPalindrome(word: String) -> Bool{
let word2 = word
let reversedWord = String(word.reversed())
if word2 == reversedWord {
print("Is Palindrome")
return true
} else {
print("Isn't Palindrome")
return false
}
}
Also I don't think that you need to return something, except you want to use it.
for example:
if isPalindrome(word: text!){
//do something
} else{
//do something
}
If you are using storyboard, check how the #IBAction and IBOutlet works. its a visual way to link objects from storyboard into your code. If you created these label, textfield, button from code then checkout the addTarget method of UIButton for how to listen for click events.
I'm wondering if there is a more efficient way to code an action that is the same with the exception of which button has been pressed and which item in a struct it relates to. Basically, I have a struct of 10 variables all of which are a boolean type and I have 10 buttons. When the user presses the button, I want to check whether it has already been pressed (using the struct) and then change the background of the button depending on the state and reverse the state. I've copied my current code for one of the buttons but thought I should be able to avoid doing this 10 times!
#IBAction func architectureButtonPressed(_ sender: Any) {
if myInterests.architecture {
myInterests.architecture = false
architectureButton.setBackgroundImage(imageUncheckedNarrow, for: .normal)
} else {
myInterests.architecture = true
architectureButton.setBackgroundImage(imageCheckedNarrow, for: .normal)
}
}
Well one simple way is to have each UIButton point to the same architectureButtonPressed IBAction method. Since the button that's pressed is passed into the method (sender) you can consult it's tag property to know the index of which field in your struct should be updated. (And then you might want to change your struct to just store an array of 10 bools, but up to you).
Then for each UIButton, whether programmatically in storyboard or nib, you'd assign the appropriate index value to the button's tag field.
Create yours IBOutlet for each button.
Create a array and store all buttons like : var arrayButtons : [UIButton] = []
arrayButtons.append[button1]
arrayButtons.append[button2]
...
Create a array of booleans to store true/false: var arrayBools : [Bool] = [] and initialize if some value.
Note that the indexes of the arrayButtons and arrayBools must be same related.
Create selector function to listen touch buttons.
button.addTarget(self, action: #selector(my_func), for: .touchUpInside)
#objc func my_func(_ sender : UIButton) {
for i in 0...arrayButtons.size-1 {
if arrayButtons[i] == sender {
if arrayBooleans[i] {
arrayBooleans[i] = false
arrayButtons[i].setImage()
} else {
arrayBooleans[i] = true
arrayButtons[i].setImage()
}
}
}
}
My suggestion is to manage the images in Interface Builder via State Config (Default/Selected)
Then assign an unique tag starting from 100 to each button and set the isSelected value in the IBAction to the corresponding struct member in a switch statement:
#IBAction func buttonPressed(_ sender: UIButton) {
switch sender.tag {
case 100: myInterests.architecture = sender.isSelected
case 101: myInterests.art = sender.isSelected
...
default: break
}
}
Alternatively use Swift's native KVC with WriteableKeypath
let keypaths : [WritableKeyPath<Interests,Bool>] = [\.architecture, \.art, \.fashion, \.history, \.localCulture, \.music, \.nature, \.shopping, \.sport, \.anything]
#IBAction func buttonPressed(_ sender: UIButton) {
let index = sender.tag - 100
let keypath = keypaths[index]
myInterests[keyPath: keypath] = sender.isSelected
}
I am new to Swift and I am having issues with deleting a character from a UI Label that I have created. I am trying to make a simple phone dailer app, and I am trying ti implement a backspace button. My UI Label is called DailerLabel, and I know I'm supposed to use the dropLast() function but I keep running into issues about mismatching types or unwrappers. I am not really sure what I am supposed to do here. I tried the thing in the commented code which didn't work, and then I tried what I listed below which doesn't either. Could anyone help me?
#IBAction func backspaceButtonPressed(_ sender: UIButton) {
if (!((DailerLabel.text?.isEmpty)!)) {
// DailerLabel.text?.substring(to: (DailerLabel.text?.index(before: (DailerLabel.text?.endIndex)!))!)
let temp = DailerLabel.text
temp?.dropLast()
DailerLabel.text = temp
}
You can try this one, replace label with your own UILabel
var name: String = label.text! //shauket , for example
name.remove(at: name.index(before: name.endIndex))
print(name) //shauke
label.text = name
print(label.text!)
You are very close. dropLast actually returns the string without the last character and you haven't stored that to anything so there is no change. You also have to conver back to String from Substring.
#IBAction func backspaceButtonPressed(_ sender: UIButton) {
if (!((DailerLabel.text?.isEmpty)!)) {
let temp = DailerLabel.text ?? ""
DailerLabel.text = String(temp.dropLast())
}
}
Here's a better version
#IBAction func backspaceButtonPressed(_ sender: UIButton) {
guard
let text = dialerLabel.text,
!text.isEmpty
else {
return
}
dialerLabel.text = String(text.dropLast())
}
I am working on an iOS application that is built around a Tab View Controller. I have created a "Contacts" tab, where a user can find and select a contact from a list. When the user selects the contact, it takes the contact's name and passes it to a different tab. That function is being done like so:
func passName(name: String) {
let navTab = self.tabBarController!.viewControllers![2] as! UINavigationController
let homeTab = navTab.viewControllers[0] as! MainController
homeTab.passedName = name
tabBarController?.selectedIndex = 2
}
Everything works as it should so far (name is loaded into text field). My issue is that the value seems to keep coming back every time I change tabs and then go back to my Home tab. For example, if I select "John" from my contacts, it will take me to the Home Tab and put John's name in a textfield. Let's say I delete the last two letters of the name, so now it is "Jo". If I load a different tab and come back, the name field has been reset to "John". It's as if the value gets re-passed every time I open the Home Tab. Also, every time I load the Home Tab after passing a name, my console prints: "Name Passed: John", so it shows that this is being processed every single time the tab appears. Here is my code for processing the name:
var passedName: String!
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
//Checks if name was passed to controller
if let validName = passedName {
print("Name passed: \(validName)")
nameTextField.text = validName
}
}
Am I passing the data incorrectly? I was thinking it might be because I have the above code being called in the viewWillAppear method, but that doesn't make sense, as essentially the data is only being passed one time from the Contacts tab. Thanks!
The problem is that you're not actually passing the value back to the original view. Apple's recommendation for passing information between classes is to use the delegate pattern. This allows the modal view to call the delegate class's function, which changes the name local to the original view because that function is declared in the original view's viewController. You can read more about the pattern in this tutorial, but I've also included a brief example relevant to your use case below.
mainViewController:
class namesTableViewController: UITableViewController, editNameDetailsViewControllerDelegate {
var name : String
#IBAction func editButtonPressed(_ sender: UIBarButtonItem) {
performSegue(withIdentifier: "editPerson", sender: self)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "editPerson" { //Modal segue
let navController = segue.destination as! UINavigationController
let controller = navController.topViewController as! editNameViewController
controller.delegate = self
if let person = sender as? Person {
print("Sending person to edit")
controller.personToEdit = person
}
} else {
super.prepare(for: segue, sender: sender)
}
}
//Protocol function
func changeName(n: String, controller: UIViewController) {
name = n
dismiss(animated: true, completion: nil)
}
}
editNameViewController:
class editNameViewController: UIViewController {
#IBOutlet weak var personNameTextField: UITextField!
var personToEdit : Person?
weak var delegate : PersonTableViewController?
override func viewDidLoad() {
super.viewDidLoad()
if personToEdit != nil {
personNameTextField.text = personToEdit?.name
}
}
// Button Actions
#IBAction func saveButtonPressed(_ sender: UIBarButtonItem) {
delegate?.personDetailsView(n: personNameTextField.text, controller: self)
}
}
Finally, the protocol class :
protocol editNameDetailsViewControllerDelegate : class {
func personDetailsView(n: String, controller: UIViewController)
}
Hope this helps.
The problem is "passedName" variable doesn't changed its value every time you edit it in your UITextField. Keep in mind that every time you change tabs, the UIViewController will call viewWillAppear and viewDidAppear. So your UITextField will always show passedName value once you select other tab and return.
I suggest that every time you edit the textfield you should update passedName value.
Sorry for my bad english.