UICollectionView reloadData() crashes after emtying datasource dictionary - swift3

Question

I have a UICollectionView which takes the results of an API search. The search is triggered by the following code. The results are appended to a dictionary [[String: Any]] and I call self.collectionView.reloadData() after my query completes.
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
var newValue = textField.text!
let location = min(range.location, newValue.characters.count)
let startIndex = newValue.characters.index(newValue.startIndex, offsetBy: location)
let endIndex = newValue.characters.index(newValue.startIndex, offsetBy: location + range.length)
let newRangeValue = Range<String.Index>(startIndex ..< endIndex)
newValue.replaceSubrange(newRangeValue, with: string)
searchView.searchFieldValueChanged(newValue)
return true
}
Then, if I want to change the search string and search again I want to empty the dictionary and call reloadData() again I get an app crash.
The error is
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'UICollectionView received layout attributes for a cell with an index path that does not exist:
Here is my datasource implementation
var searchResults = [[String: Any]]()
let layout: UICollectionViewFlowLayout = {
let layout = UICollectionViewFlowLayout()
layout.sectionInset = UIEdgeInsets(top: 0, left: 10, bottom: 0, right: 10)
layout.estimatedItemSize.height = 200
layout.estimatedItemSize.width = 200
layout.minimumInteritemSpacing = 10
layout.minimumLineSpacing = 10
return layout
}()
collectionView = UICollectionView(frame: self.frame, collectionViewLayout: layout)
collectionView.delegate = self
collectionView.dataSource = self
collectionView.register(LanesCollectionViewCell.self, forCellWithReuseIdentifier: cellId)
collectionView.backgroundColor = .yellow // Constants.APP_BACKGROUND_COLOR
collectionView.alwaysBounceVertical = true
collectionView.clipsToBounds = true
collectionView.translatesAutoresizingMaskIntoConstraints = false
func numberOfSections(in collectionView: UICollectionView) -> Int {
return 1
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
if searchResults.count == 0 {
collectionView.alpha = 0.0
} else {
collectionView.alpha = 1.0
}
return searchResults.count
}
after query
func parseMoreData(jsonData: [String: Any]) {
let items = jsonData["items"] as! [[String: Any]]
self.collectionView.layoutIfNeeded()
self.collectionView.reloadData()
}
}
func searchFieldValueChanged(_ textValue: String) {
searchResults = []

Answer 1

This looks fixed by using this instead of layoutIfNeeded()
collectionView.reloadData()
collectionView.collectionViewLayout.invalidateLayout()