I need to move a method for adding and removing a logging view inside an Extension, in order to give it to every controller. to do so I added a inout UIVew parameter to original method, where I used a global var for the view. no I have this error
Value of type 'UIViewController' has no member 'containerForLoading'
removing self from self.containerForLoading will give error:
Escaping closure captures 'inout' parameter 'containerForLoading'
inside the animate closure (see the comment) is all wrong the entire process or I am lost at the last step?
extension UIViewController {
func showLoadingView(containerForLoading: inout UIView, uponView: UIView) {
containerForLoading = UIView(frame: uponView.bounds)
uponView.addSubview(containerForLoading)
containerForLoading.backgroundColor = .white
containerForLoading.alpha = 0
UIView.animate(withDuration: 0.24) { self.containerForLoading.alpha = 0.8 } //here the error
let activivityIndicator = UIActivityIndicatorView()
containerForLoading.addSubview(activivityIndicator)
activivityIndicator.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
activivityIndicator.centerYAnchor.constraint(equalTo: uponView.centerYAnchor),
activivityIndicator.centerXAnchor.constraint(equalTo: uponView.centerXAnchor)
])
activivityIndicator.startAnimating()
}
func removeLoading(containerForLoading: inout UiView, uponView: UIView) {
containerForLoading.removeFromSuperview()
}
}
this is the code inside the original viewController
using this var
var containerForLoading = UIView()
called this way when needed
self.showLoadingView(uponView: self.view)
extension ViewController {
func showLoadingView(uponView: UIView) {
containerForLoading = UIView(frame: uponView.bounds)
uponView.addSubview(containerForLoading)
containerForLoading.backgroundColor = .white
containerForLoading.alpha = 0
UIView.animate(withDuration: 0.24) { self.containerForLoading.alpha = 0.8 }
let activivityIndicator = UIActivityIndicatorView()
containerForLoading.addSubview(activivityIndicator)
activivityIndicator.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
activivityIndicator.centerYAnchor.constraint(equalTo: uponView.centerYAnchor),
activivityIndicator.centerXAnchor.constraint(equalTo: uponView.centerXAnchor)
])
activivityIndicator.startAnimating()
}
func removeLoading(uponView: UIView) {
containerForLoading.removeFromSuperview()
}
}
You could make loadingContainerTag a local variable, and change the parameter name to something else. Then assign to the parameter just after you create the container view:
extension UIViewController {
func showLoadingView(containerForLoadingProperty: inout UIView, uponView: UIView) {
// local variable!
let containerForLoading = UIView(frame: uponView.bounds)
// also set property
containerForLoadingProperty = containerForLoading
uponView.addSubview(containerForLoading)
containerForLoading.backgroundColor = .white
containerForLoading.alpha = 0
// no "self."!
UIView.animate(withDuration: 0.24) { containerForLoading.alpha = 0.8 }
// ... everything else is the same
removeLoading could just have one non-inout parameter:
func removeLoading(containerForLoadingProperty: UIView) {
containerForLoadingProperty.removeFromSuperview()
}
But...
It is very weird for a method that shows a loading indicator, to need an inout parameter. It shouldn't assign to a special property that the caller provides. It should just show the loading indicator!
The purpose of your containerForLoading property is so that in removeLoading, you know which view to remove. If you don't store the containerForLoading view somewhere in a property, you wouldn't know which view to remove, right? Well, we can use the tag property of a view to identify views, so you can just make containerForLoading a local variable, and later in removeLoading, use its tag to find it.
extension UIViewController {
static let loadingContainerTag = <a number you like>
func showLoadingView(uponView: UIView) {
// local variable!
let containerForLoading = UIView(frame: uponView.bounds)
uponView.addSubview(containerForLoading)
containerForLoading.backgroundColor = .white
containerForLoading.alpha = 0
// set tag
containerForLoading.tag = UIViewController.loadingContainerTag
// no "self."!
UIView.animate(withDuration: 0.24) { containerForLoading.alpha = 0.8 }
let activivityIndicator = UIActivityIndicatorView()
containerForLoading.addSubview(activivityIndicator)
activivityIndicator.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
activivityIndicator.centerYAnchor.constraint(equalTo: uponView.centerYAnchor),
activivityIndicator.centerXAnchor.constraint(equalTo: uponView.centerXAnchor)
])
activivityIndicator.startAnimating()
}
func removeLoading(uponView: UIView) {
// find view with the tag
uponView.viewWithTag(UIViewController.loadingContainerTag)?.removeFromSuperview()
}
}