Change height of UIPopoverController, to height of UITextView - ios

Question

In my app there is the need for a popover element, that displays the full description.
There is a normal UITextView in the UIViewController that displays the first 4 lines of the description. Now when the user clicks on that description the full description must be displayed. This will be done with the popover control recently introduced for the iPhone.
At the moment everything works, except for the fact that I want the popover to have a height that is exactly the height of the string in the UITextView in the DescriptionPopupViewController. This way if the description is longer, it will automatically make the popover higher.
The following code is called when the user clicks the UITextView:
func textViewShouldBeginEditing(textView: UITextView) -> Bool {
if textView == descriptionTextView {
let sb = UIStoryboard(name: "Main-alternative", bundle: nil)
let popoverController = sb.instantiateViewControllerWithIdentifier("descriptionControllerID") as! DescriptionPopupViewController
popoverController.modalPresentationStyle = UIModalPresentationStyle.Popover
popoverController.popoverPresentationController?.delegate = popoverController;
popoverController.popoverPresentationController?.sourceView = descriptionTextView
popoverController.popoverPresentationController?.sourceRect = descriptionTextView.frame
popoverController.descriptionText = currentObject?["description"] as! String
if let frameHeight = popoverController.textView?.frame.height {
popoverController.preferredContentSize = CGSizeMake(fixedWidth, frameHeight)
}
self.presentViewController(popoverController, animated: true, completion: nil)
}
return false
}
So the preferredContentSize should get the height of the enclosed UITextView in the DescriptionPopupViewController. However when I try to do something like this it won't work:
I think because the frameHeight is nil

Answer 1

When the UIViewController is created its view hierarchy may not (and so all subviews, properties will still be nil), for optimization reasons it may not be loaded. You need to the access controller's view to force it to load its view hierarchy. So you need to update you code like the following:
func textViewShouldBeginEditing(textView: UITextView) -> Bool {
if textView == descriptionTextView {
let sb = UIStoryboard(name: "Main-alternative", bundle: nil)
let popoverController = sb.instantiateViewControllerWithIdentifier("descriptionControllerID") as! DescriptionPopupViewController
popoverController.modalPresentationStyle = UIModalPresentationStyle.Popover
popoverController.popoverPresentationController?.delegate = popoverController;
popoverController.popoverPresentationController?.sourceView = descriptionTextView
popoverController.popoverPresentationController?.sourceRect = descriptionTextView.frame
// forces to load its view hierarchy
var view = popoverController.view
popoverController.descriptionText = currentObject?["description"] as! String
if let frameHeight = popoverController.textView?.frame.height {
popoverController.preferredContentSize = CGSizeMake(fixedWidth, frameHeight)
}
self.presentViewController(popoverController, animated: true, completion: nil)
}
return false
}
I hope this help you.