Run API and update array before Navigation - ios

Question

So I have an app that lets you search for words and gives you the definition and other details about it. I use 2 different apis so if you use a wildcard search (e.g. ?OUSE) you get all the possibilities and if you put in the whole word you just get the one result.
To cut down on API usage, when run for a single word I collect all the data in a WordDetail object. Similary, when run for a wildcard search, each word is created as a WordDetail object but with a lot of missing data.
My plan is, for wildcard search, when you select a specific word, it'll then go use the API again and retrieve the data, update the array, and then navigate you to the DetailViewController.
My problem is (I think), it's navigating to the DetailViewController before it's updated the array. Is there a way to make things wait before it has all the information before navigating?
The did select function looks like this...
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
var word: WordDetails?
word = results[indexPath.row]
if word?.results.count == 0 {
fetchWords(word: word!.word, updating: true)
}
print(word?.word)
print(word?.pronunciation)
let detailVC = TabBarController()
detailVC.selectedWord = word
detailVC.navigationItem.title = word?.word.capitalizingFirstLetter()
tableView.deselectRow(at: indexPath, animated: true)
navigationController?.pushViewController(detailVC, animated: true)
}
and the update to the array happens here...
func parseJSON(resultData: Data, update: Bool){
let decoder = JSONDecoder()
do {
let decodedData = try decoder.decode(WordDetails.self, from: resultData)
if update {
if let row = self.results.firstIndex(where: {$0.word == decodedData.word}) {
self.results[row] = decodedData
}
} else {
results.append(decodedData)
DispatchQueue.main.async {
self.resultLabel.text = "\(self.results.count) results found"
self.resultsView.reloadData()
}
}
} catch {
print(error)
}
}
could be a timing problem or might be a stupid approach. My alternative is to just run the api call again in the DetailViewController for words that are missing data as they came from a wildcard search.
UPDATE
Found a solution using DispatchSemaphore
Define it globally
let semaphore = DispatchSemaphore(value: 0)
Ask the code to wait for a signal before proceding, which I added to the didSelectRowAt function
_ = semaphore.wait(timeout: .distantFuture)
And then send a signal when the code has done what it needed to do e.g.
if update {
if let row = self.results.firstIndex(where: {$0.word == decodedData.word}) {
self.results[row] = decodedData
DispatchQueue.main.async {
self.resultsView.reloadData()
}
semaphore.signal()
}
}
Which then allows the rest of the code to carry on. Has worked perfectly in the few test cases I've tried.