UICollectionView is not working in custom keyboard extension - ios

Question

I am trying to implement UICollectionView in custom keyboard extension but it is not working.
This is what I am doing inside viewDidLoad method.
let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
layout.sectionInset = UIEdgeInsets(top: 20, left: 10, bottom: 10, right: 10)
layout.itemSize = CGSize(width: 90, height: 120)
collectionView = UICollectionView(frame: self.view.frame, collectionViewLayout: layout)
collectionView.dataSource = self
collectionView.delegate = self
collectionView.registerClass(UICollectionViewCell.self, forCellWithReuseIdentifier: "Cell")
collectionView.backgroundColor = UIColor.whiteColor()
self.view.addSubview(collectionView)
I have added UICollectionViewDelegateFlowLayout and UICollectionViewDataSource protocols to my class and then implemented dataSource methods as shown below
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 14
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("Cell", forIndexPath: indexPath)
cell.backgroundColor = UIColor.orangeColor()
return cell
}
The same code is working as expected in app bundle. I don't understand why it has a different behaviour in keyboard extension.
Is there anything that I am missing here, What do I need to do to get it working in keyboard extension?

Answer 1

The collection view will be visible when you provide constraints for the collectionView.
Code :
collectionView.translatesAutoresizingMaskIntoConstraints = false
self.view.addSubview(collectionView)
collectionView.topAnchor.constraintEqualToAnchor(topLayoutGuide.bottomAnchor,constant: 0.0).active = true
collectionView.bottomAnchor.constraintEqualToAnchor(bottomLayoutGuide.topAnchor, constant: 0.0).active = true
collectionView.leadingAnchor.constraintEqualToAnchor(view.leadingAnchor).active = true
collectionView.trailingAnchor.constraintEqualToAnchor(view.trailingAnchor).active = true

Answer 2

Try this once bro:
override func viewDidLoad() {
super.viewDidLoad()
let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
layout.sectionInset = UIEdgeInsets(top: 20, left: 10, bottom: 10, right: 10)
layout.itemSize = CGSize(width: 10, height: 10)
collectionView = UICollectionView(frame: self.view.frame, collectionViewLayout: layout)
collectionView.dataSource = self
collectionView.delegate = self
collectionView.registerClass(UICollectionViewCell.self, forCellWithReuseIdentifier: "Cell")
collectionView.backgroundColor = UIColor.whiteColor()
self.view.addSubview(collectionView)
// Perform custom UI setup here
self.nextKeyboardButton = UIButton(type: .System)
self.nextKeyboardButton.setTitle(NSLocalizedString("Next Keyboard", comment: "Title for 'Next Keyboard' button"), forState: .Normal)
self.nextKeyboardButton.sizeToFit()
self.nextKeyboardButton.translatesAutoresizingMaskIntoConstraints = false
self.nextKeyboardButton.addTarget(self, action: "advanceToNextInputMode", forControlEvents: .TouchUpInside)
self.view.addSubview(self.nextKeyboardButton)
let nextKeyboardButtonLeftSideConstraint = NSLayoutConstraint(item: self.nextKeyboardButton, attribute: .Left, relatedBy: .Equal, toItem: self.view, attribute: .Left, multiplier: 1.0, constant: 0.0)
let nextKeyboardButtonBottomConstraint = NSLayoutConstraint(item: self.nextKeyboardButton, attribute: .Bottom, relatedBy: .Equal, toItem: self.view, attribute: .Bottom, multiplier: 1.0, constant: 0.0)
self.view.addConstraints([nextKeyboardButtonLeftSideConstraint, nextKeyboardButtonBottomConstraint])
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated
}
override func textWillChange(textInput: UITextInput?) {
// The app is about to change the document's contents. Perform any preparation here.
}
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 14
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("Cell", forIndexPath: indexPath)
cell.backgroundColor = UIColor.orangeColor()
return cell
}
override func textDidChange(textInput: UITextInput?) {
// The app has just changed the document's contents, the document context has been updated.
var textColor: UIColor
let proxy = self.textDocumentProxy
if proxy.keyboardAppearance == UIKeyboardAppearance.Dark {
textColor = UIColor.whiteColor()
} else {
textColor = UIColor.blackColor()
}
self.nextKeyboardButton.setTitleColor(textColor, forState: .Normal)`}`