I'm trying to create a dynamic menu where I send the text and the action of a button from one controller to the next controller and then I want to generate the button that runs the action, but I'm having trouble with the syntax.
So as an example in the first controller i have:
let vc = storyboard.instantiateViewController(withIdentifier:
"CompetitiveKPIChart") as! CompetitiveKPIChartViewController
vc.Menu = [["Menu1":ClickBack()],["Menu2":ClickBack()],["Menu3":ClickBack()]]
func ClickBack() {
self.dismiss(animated: true, completion: {});
}
and in the second controller:
var Menu : [Dictionary<String,()>] = []
override func viewDidLoad() {
let gesture2 = UITapGestureRecognizer(target: self,action: Menu["Menu1"])
btnBack.addGestureRecognizer(gesture2)
}
How can I call the ClickBack() from the first controller in the second controller GestureRecognizer?
The syntax of your Menu declaration is wrong - it should be () -> () for a void function, not ().
This works in Playground, your syntax does not...
var menu : [Dictionary<String,() -> ()>] = [] // Don't use capitals for variables...
func aFunc() {
print("Hello aFunc")
}
menu = [["aFunc": aFunc]]
menu.first!["aFunc"]!() // Prints "Hello aFunc"
However, I think there is a second problem with your code. Your line
UITapGestureRecognizer(target: self,action: Menu["Menu1"])
cannot compile, as Menu is an array, not a dictionary. I think you probably meant
var menu : Dictionary<String,() -> ()> = [:]
in which case your set-up code should say
vc.menu = ["Menu1":ClickBack, "Menu2":ClickBack, "Menu3":ClickBack]
However, there is a final, and probably insurmountable problem, which is that your code
override func viewDidLoad() {
let gesture2 = UITapGestureRecognizer(target: self, action: menu["Menu1"])
btnBack.addGestureRecognizer(gesture2)
}
will still give an error, since action: needs to be a Selector, which is an #objc message identifier, not a Swift function.
I'm afraid I can't see a good way to make this (rather clever) idea work. Time to refactor?
Related
Trying to create a custom drop-down and facing issues in passing on data and retrieving the user selection from the custom drop-down. The solution however works when I use static var.
In the below code, I have a viewController class from where I am programmatically calling a popOver.
let countryDropDown = customDropdown()
#IBAction func btMultiCountry(_ sender: Any) {
ViewController.countryDropDown.removeAll() //fuction to clear the array before load
for c in g.country{ //Array from which all items are loaded on the custom dropdown
countryDropDown.addItems(labelText: c.countryName!, toggleState: 1) //passing the values in the add function to update the Array
}
countryDropDown.showDropdown(btMultiCountry) //programatically calling the function to display popover that has the collection view with the countries as items.
}
class customDropdown: NSViewController {
#IBOutlet weak var cvDropDown: NSCollectionView!
var pop = NSPopover() // if I put static var, the popover closes with the OK button as required, however, without static the OK button doest do anything
var dropDownLabelText = [String]() //if I put static var, the values are shown on the collection view without any issue. Without static the array is blank that was load from additems function
var dropDownToggle = [Int]() // same as above
var selectedItemsIndex: [Int] {
var a = [Int]()
for (i,t) in dropDownToggle.enumerated() {
if t == 1 {
a.append(i)
print(a)
}
}
return a
}
func showDropdown(_ sender: NSButton){
let storyboard = NSStoryboard(name: NSStoryboard.Name("Main"), bundle: nil)
let VC = storyboard.instantiateController(withIdentifier: "dropDownForm") as? customDropdown
pop.contentViewController = VC
pop.behavior = NSPopover.Behavior.transient
pop.show(relativeTo: sender.bounds, of: sender, preferredEdge: NSRectEdge.minY)
print(pop)
}
#IBAction func btOK(_ sender: Any) { //this function does not close the popover if there is not static mention above
pop.close()
}
I tried putting static when declaring the variables and it worked. I do not want static and want to create different instances of the class that gives me selectedItemsIndex
For eg:
let countryDropDown = customDropdown()
let personDropDown = customDropdown()
I should be able to get a different values for countryDropDown.selectedItemsIndex and personDropDown.selectedItemsIndex
Any help is appreciated.
I'm programmatically adding a UITapGestureRecognizer to one of my views:
let gesture = UITapGestureRecognizer(target: self, action: #selector(self.handleTap(modelObj:myModelObj)))
self.imageView.addGestureRecognizer(gesture)
func handleTap(modelObj: Model) {
// Doing stuff with model object here
}
The first problem I encountered was "Argument of '#selector' does not refer to an '#Objc' method, property, or initializer.
Cool, so I added #objc to the handleTap signature:
#objc func handleTap(modelObj: Model) {
// Doing stuff with model object here
}
Now I'm getting the error "Method cannot be marked #objc because the type of the parameter cannot be represented in Objective-C.
It's just an image of the map of a building, with some pin images indicating the location of points of interest. When the user taps one of these pins I'd like to know which point of interest they tapped, and I have a model object which describes these points of interest. I use this model object to give the pin image it's coordinates on the map so I thought it would have been easy for me to just send the object to the gesture handler.
It looks like you're misunderstanding a couple of things.
When using target/action, the function signature has to have a certain form…
func doSomething()
or
func doSomething(sender: Any)
or
func doSomething(sender: Any, forEvent event: UIEvent)
where…
The sender parameter is the control object sending the action message.
In your case, the sender is the UITapGestureRecognizer
Also, #selector() should contain the func signature, and does NOT include passed parameters. So for…
func handleTap(sender: UIGestureRecognizer) {
}
you should have…
let gesture = UITapGestureRecognizer(target: self, action: #selector(handleTap(sender:)))
Assuming the func and the gesture are within a view controller, of which modelObj is a property / ivar, there's no need to pass it with the gesture recogniser, you can just refer to it in handleTap
Step 1: create the custom object of the sender.
step 2: add properties you want to change in that a custom object of the sender
step 3: typecast the sender in receiving function to a custom object and access those properties
For eg:
on click of the button if you want to send the string or any custom object then
step 1: create
class CustomButton : UIButton {
var name : String = ""
var customObject : Any? = nil
var customObject2 : Any? = nil
convenience init(name: String, object: Any) {
self.init()
self.name = name
self.customObject = object
}
}
step 2-a: set the custom class in the storyboard as well
step 2-b: Create IBOutlet of that button with a custom class as follows
#IBOutlet weak var btnFullRemote: CustomButton!
step 3: add properties you want to change in that a custom object of the sender
btnFullRemote.name = "Nik"
btnFullRemote.customObject = customObject
btnFullRemote.customObject2 = customObject2
btnFullRemote.addTarget(self, action: #selector(self.btnFullRemote(_:)), for: .touchUpInside)
step 4: typecast the sender in receiving function to a custom object and access those properties
#objc public func btnFullRemote(_ sender: Any) {
var name : String = (sender as! CustomButton).name as? String
var customObject : customObject = (sender as! CustomButton).customObject as? customObject
var customObject2 : customObject2 = (sender as! CustomButton).customObject2 as? customObject2
}
Swift 5.0 iOS 13
I concur a great answer by Ninad. Here is my 2 cents, the same and yet different technique; a minimal version.
Create a custom class, throw a enum to keep/make the code as maintainable as possible.
enum Vs: String {
case pulse = "pulse"
case precision = "precision"
}
class customTap: UITapGestureRecognizer {
var cutomTag: String?
}
Use it, making sure you set the custom variable into the bargin. Using a simple label here, note the last line, important labels are not normally interactive.
let precisionTap = customTap(target: self, action: #selector(VC.actionB(sender:)))
precisionTap.customTag = Vs.precision.rawValue
precisionLabel.addGestureRecognizer(precisionTap)
precisionLabel.isUserInteractionEnabled = true
And setup the action using it, note I wanted to use the pure enum, but it isn't supported by Objective C, so we go with a basic type, String in this case.
#objc func actionB(sender: Any) {
// important to cast your sender to your cuatom class so you can extract your special setting.
let tag = customTag as? customTap
switch tag?.sender {
case Vs.pulse.rawValue:
// code
case Vs.precision.rawValue:
// code
default:
break
}
}
And there you have it.
cell.btn.tag = indexPath.row //setting tag
cell.btn.addTarget(self, action: #selector(showAlert(_ :)), for: .touchUpInside)
#objc func showAlert(_ sender: UIButton){
print("sender.tag is : \(sender.tag)")// getting tag's value
}
Just create a custom class of UITapGestureRecognizer =>
import UIKit
class OtherUserProfileTapGestureRecognizer: UITapGestureRecognizer {
let userModel: OtherUserModel
init(target: AnyObject, action: Selector, userModel: OtherUserModel) {
self.userModel = userModel
super.init(target: target, action: action)
}
}
And then create UIImageView extension =>
import UIKit
extension UIImageView {
func gotoOtherUserProfile(otherUserModel: OtherUserModel) {
isUserInteractionEnabled = true
let gestureRecognizer = OtherUserProfileTapGestureRecognizer(target: self, action: #selector(self.didTapOtherUserImage(_:)), otherUserModel: otherUserModel)
addGestureRecognizer(gestureRecognizer)
}
#objc internal func didTapOtherUserImage(_ recognizer: OtherUserProfileTapGestureRecognizer) {
Router.shared.gotoOtherUserProfile(otherUserModel: recognizer.otherUserModel)
}
}
Now use it like =>
self.userImageView.gotoOtherUserProfile(otherUserModel: OtherUserModel)
You can use an UIAction instead:
self.imageView.addAction(UIAction(identifier: UIAction.Identifier("imageClick")) { [weak self] action in
self?.handleTap(modelObj)
}, for: .touchUpInside)
that may be a terrible practice but I simply add whatever I want to restore to
button.restorationIdentifier = urlString
and
#objc func openRelatedFact(_ sender: Any) {
if let button = sender as? UIButton, let stringURL = factButton.restorationIdentifier, let url = URL(string: stringURL) {
if UIApplication.shared.canOpenURL(url) {
UIApplication.shared.open(url, options: [:])
}
}
}
i tried to use lazy var but it didn't work, so i need to solve this cz the "Add Graph" button is not working:
var addGraphButton: NSButton = {
let button = NSButton(title: "Add Graph", target: self, action: #selector (addGraph))
button.translatesAutoresizingMaskIntoConstraints = false
return button // 'self' refers to the method 'EquationController.self', which may be unexpected
}()
In the context you posed, self refers to the EquationController type itself, not an object which is an instance of EquationController, which is what you intended.
I.e., self.performSelector(#selector(addGraph)) would end up calling class func addGraph, not your instance method func addGraph.
To fix this, make the variable lazy, which will defer the instantiation of the button to where you first use it, at which point the initialization of self is complete. You cannot reference self of the instance in a closure-initialized stored property unless you make it lazy. E.g.:
lazy var addGraphButton: NSButton = {
let button = NSButton(title: "Add Graph", target: self, action: #selector(addGraph))
button.translatesAutoresizingMaskIntoConstraints = false
return button
}()
You said:
i tried to use lazy var but it didn’t work
This is the correct solution. You did not share your addGraph implementation, but make sure you add #objc qualifier. E.g., you would generally define the action to take one parameter:
#objc func addGraph(_ sender: Any) { ... }
And then:
lazy var addGraphButton: NSButton = {
let button = NSButton(title: "Add Graph", target: self, action: #selector(addGraph(_:)))
button.translatesAutoresizingMaskIntoConstraints = false
return button
}()
I'm programmatically adding a UITapGestureRecognizer to one of my views:
let gesture = UITapGestureRecognizer(target: self, action: #selector(self.handleTap(modelObj:myModelObj)))
self.imageView.addGestureRecognizer(gesture)
func handleTap(modelObj: Model) {
// Doing stuff with model object here
}
The first problem I encountered was "Argument of '#selector' does not refer to an '#Objc' method, property, or initializer.
Cool, so I added #objc to the handleTap signature:
#objc func handleTap(modelObj: Model) {
// Doing stuff with model object here
}
Now I'm getting the error "Method cannot be marked #objc because the type of the parameter cannot be represented in Objective-C.
It's just an image of the map of a building, with some pin images indicating the location of points of interest. When the user taps one of these pins I'd like to know which point of interest they tapped, and I have a model object which describes these points of interest. I use this model object to give the pin image it's coordinates on the map so I thought it would have been easy for me to just send the object to the gesture handler.
It looks like you're misunderstanding a couple of things.
When using target/action, the function signature has to have a certain form…
func doSomething()
or
func doSomething(sender: Any)
or
func doSomething(sender: Any, forEvent event: UIEvent)
where…
The sender parameter is the control object sending the action message.
In your case, the sender is the UITapGestureRecognizer
Also, #selector() should contain the func signature, and does NOT include passed parameters. So for…
func handleTap(sender: UIGestureRecognizer) {
}
you should have…
let gesture = UITapGestureRecognizer(target: self, action: #selector(handleTap(sender:)))
Assuming the func and the gesture are within a view controller, of which modelObj is a property / ivar, there's no need to pass it with the gesture recogniser, you can just refer to it in handleTap
Step 1: create the custom object of the sender.
step 2: add properties you want to change in that a custom object of the sender
step 3: typecast the sender in receiving function to a custom object and access those properties
For eg:
on click of the button if you want to send the string or any custom object then
step 1: create
class CustomButton : UIButton {
var name : String = ""
var customObject : Any? = nil
var customObject2 : Any? = nil
convenience init(name: String, object: Any) {
self.init()
self.name = name
self.customObject = object
}
}
step 2-a: set the custom class in the storyboard as well
step 2-b: Create IBOutlet of that button with a custom class as follows
#IBOutlet weak var btnFullRemote: CustomButton!
step 3: add properties you want to change in that a custom object of the sender
btnFullRemote.name = "Nik"
btnFullRemote.customObject = customObject
btnFullRemote.customObject2 = customObject2
btnFullRemote.addTarget(self, action: #selector(self.btnFullRemote(_:)), for: .touchUpInside)
step 4: typecast the sender in receiving function to a custom object and access those properties
#objc public func btnFullRemote(_ sender: Any) {
var name : String = (sender as! CustomButton).name as? String
var customObject : customObject = (sender as! CustomButton).customObject as? customObject
var customObject2 : customObject2 = (sender as! CustomButton).customObject2 as? customObject2
}
Swift 5.0 iOS 13
I concur a great answer by Ninad. Here is my 2 cents, the same and yet different technique; a minimal version.
Create a custom class, throw a enum to keep/make the code as maintainable as possible.
enum Vs: String {
case pulse = "pulse"
case precision = "precision"
}
class customTap: UITapGestureRecognizer {
var cutomTag: String?
}
Use it, making sure you set the custom variable into the bargin. Using a simple label here, note the last line, important labels are not normally interactive.
let precisionTap = customTap(target: self, action: #selector(VC.actionB(sender:)))
precisionTap.customTag = Vs.precision.rawValue
precisionLabel.addGestureRecognizer(precisionTap)
precisionLabel.isUserInteractionEnabled = true
And setup the action using it, note I wanted to use the pure enum, but it isn't supported by Objective C, so we go with a basic type, String in this case.
#objc func actionB(sender: Any) {
// important to cast your sender to your cuatom class so you can extract your special setting.
let tag = customTag as? customTap
switch tag?.sender {
case Vs.pulse.rawValue:
// code
case Vs.precision.rawValue:
// code
default:
break
}
}
And there you have it.
cell.btn.tag = indexPath.row //setting tag
cell.btn.addTarget(self, action: #selector(showAlert(_ :)), for: .touchUpInside)
#objc func showAlert(_ sender: UIButton){
print("sender.tag is : \(sender.tag)")// getting tag's value
}
Just create a custom class of UITapGestureRecognizer =>
import UIKit
class OtherUserProfileTapGestureRecognizer: UITapGestureRecognizer {
let userModel: OtherUserModel
init(target: AnyObject, action: Selector, userModel: OtherUserModel) {
self.userModel = userModel
super.init(target: target, action: action)
}
}
And then create UIImageView extension =>
import UIKit
extension UIImageView {
func gotoOtherUserProfile(otherUserModel: OtherUserModel) {
isUserInteractionEnabled = true
let gestureRecognizer = OtherUserProfileTapGestureRecognizer(target: self, action: #selector(self.didTapOtherUserImage(_:)), otherUserModel: otherUserModel)
addGestureRecognizer(gestureRecognizer)
}
#objc internal func didTapOtherUserImage(_ recognizer: OtherUserProfileTapGestureRecognizer) {
Router.shared.gotoOtherUserProfile(otherUserModel: recognizer.otherUserModel)
}
}
Now use it like =>
self.userImageView.gotoOtherUserProfile(otherUserModel: OtherUserModel)
You can use an UIAction instead:
self.imageView.addAction(UIAction(identifier: UIAction.Identifier("imageClick")) { [weak self] action in
self?.handleTap(modelObj)
}, for: .touchUpInside)
that may be a terrible practice but I simply add whatever I want to restore to
button.restorationIdentifier = urlString
and
#objc func openRelatedFact(_ sender: Any) {
if let button = sender as? UIButton, let stringURL = factButton.restorationIdentifier, let url = URL(string: stringURL) {
if UIApplication.shared.canOpenURL(url) {
UIApplication.shared.open(url, options: [:])
}
}
}
I recently saw the code down below. Is it possible to link a bar button item to multiple URLs? i.e. by tapping the button, I can then choose which website I wish to go to at runtime? Or can I only link a bar button to one URL?
override func viewDidLoad() {
super.viewDidLoad()
googleButton.addTarget(self, action: "didTapGoogle", forControlEvents: .TouchUpInside)}
and
#IBAction func didTapGoogle(sender: AnyObject) {
UIApplication.sharedApplication().openURL(NSURL(string:"http://www.google.com")!)}
Use it as sidebar menu.
This library keeps your sidebar menu over viewcontroller and navigation bar.
https://github.com/balram3429/BTSimpleSideMenu
It is in objective c, but you can use it by bridging. there are other side bar menus are also available in swift, just make sure it has to be open over view controller and navigation bar.
Import this 2 in bridging file.
//#import "BTSimpleSideMenuClass.h"
//#import "BTSimpleMenuItemClass.h"
Make object
var objBTSimpleSideMenuClass = BTSimpleSideMenuClass()
Import delegate
class YourClassName: UIViewController, BTSimpleSideMenuDelegate {
}
From ViewDidLoad or ViewWillAppear call this method and pass array with name, image etc
func setupOptionMenu(noOfItems : NSMutableArray)
{
objBTSimpleSideMenuClass.delegate = self
let ary : NSMutableArray = []
for var i = 0; i < noOfItems.count; i++
{
let item = BTSimpleMenuItemClass.init(title: noOfItems[i] as! String, image: nil) { (success, item) -> Void in
self.methodOptionMenuTap1()
//self.methodOptionMenuTap2()
//self.methodOptionMenuTap3()
}
ary.addObject(item)
}
let swiftArray = ary as NSArray
objBTSimpleSideMenuClass = BTSimpleSideMenuClass.init(item: swiftArray as [AnyObject], addToViewController: self)
}
Hope this will help you a lot.
All the best.