Outputting element from two-dimensional array from separate class - ios

Question

I need to output the second element from a two-dimensional array from one class to a TableViewController. I've tried a couple things, such as data.reduce into:, with no luck. The FirstViewController is supposed to be populated with the three genres "Action, Suspense and Romance", which can then be clicked on to show all the movies that belong to that genre.
First Class:
import Foundation
protocol MovieModelDelegate: class {
func didRecieveDataUpdate(data: [[String]])
}
class MovieModel {
weak var delegate: MovieModelDelegate?
var genreArray: [String] = []
let data: [[String]] = [
["Avatar", "Action"],
["Limitless", "Suspense"],
["Die Hard", "Action"],
["The Avengers", "Action"],
["The Notebook", "Romance"],
["Lakehouse", "Romance"],
["Gone Girl", "Suspense"],
["Deadpool", "Action"],
["Passengers", "Suspense"],
["Inception", "Suspense"],
["Mission Impossible", "Action"]
]
func requestData() {
let movie: [[String]] = data
delegate?.didRecieveDataUpdate(data: movie)
}
}
**TableView Class:**
class FirstTableView: UITableViewController, MovieModelDelegate {
var model = MovieModel()
var selectedGenre: String = ""
override func viewDidLoad() {
super.viewDidLoad()
model.delegate = self
model.requestData()
}
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return model.genreArray.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "GenreCells", for: indexPath) as! TableViewCell
cell.genreLabel?.text = model.genreArray[indexPath.item]
return cell
}
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
selectedGenre = model.data[indexPath.row]
selectedGenre = ""
for indexPath in model.data{
if indexPath[1] == selectedGenre{
selectedGenre.append(indexPath[0])
}
}
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if (segue.identifier == "pushToMovies") {
if let VC = segue.destination as? FilteredSelection {
VC.selectedMovies = [selectedGenre]
}
}
}
func didRecieveDataUpdate(data: [[String]]) {
}
deinit{
}
}

Answer 1

You need to change the data into a form that can then be indexed by a tableview. I would change it into a dictionary using the following code.
let genreDictionary = data.reduce(into: [:]) { d, element in
d[element[1], default: []].append(element[0])
}
This will create the following Dictionary
["Suspense": ["Limitless", "Gone Girl", "Passengers", "Inception"],
"Romance": ["The Notebook", "Lakehouse"],
"Action": ["Avatar", "Die Hard", "The Avengers", "Deadpool", "Mission Impossible"]]
Then in your tableview functions you use the dictionary as follows
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return model.genreDictionary.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "GenreCells", for: indexPath) as! TableViewCell
let d = model.genreDictionary
cell.genreLabel?.text = d[d.keys.index(d.startIndex, offsetBy: indexPath.row)].key
return cell
}
When you need the array of films for a certain tableview row you can use the following
let d = model.genreDictionary
let arrayOfFilms = d[d.keys.index(d.startIndex, offsetBy: indexPath.row)].value

Answer 2

You can use a Set to get all Genres without to have duplicates.
I recognized you want to display the genres in your TableView with model.genreArray but your genreArray is always empty because you never append data to it.
The second thing I recoginzed: In your TableViewController you
implemented the didReciveDataUpdate function, but you didnt do
anything with it.
First Class:
import Foundation
protocol MovieModelDelegate: class {
func didRecieveDataUpdate(data: [[String]])
}
class MovieModel {
weak var delegate: MovieModelDelegate?
let data: [[String]] = [
["Avatar", "Action"],
["Limitless", "Suspense"],
["Die Hard", "Action"],
["The Avengers", "Action"],
["The Notebook", "Romance"],
["Lakehouse", "Romance"],
["Gone Girl", "Suspense"],
["Deadpool", "Action"],
["Passengers", "Suspense"],
["Inception", "Suspense"],
["Mission Impossible", "Action"]
]
private var genres = [String]()
public init() {
for dataSet in data {
self.genres.append(dataSet[1])
}
//this will generate a array with only uniqe genres
var genreArray = Array(Set(self.genres))
}
func requestData() {
let movie: [[String]] = data
delegate?.didRecieveDataUpdate(data: movie)
}
}
FirstTableView Class:
(view didReciveDataUpdate function)
class FirstTableView: UITableViewController, MovieModelDelegate {
var model = MovieModel()
var selectedGenre: String = ""
override func viewDidLoad() {
super.viewDidLoad()
model.delegate = self
model.requestData()
}
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return model.genreArray.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "GenreCells", for: indexPath) as! TableViewCell
cell.genreLabel?.text = model.genreArray[indexPath.row]
return cell
}
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
//To get the Genre
selectedGenre = model.data[indexPath.row][1]
for indexPath in model.data{
if indexPath[1] == selectedGenre{
selectedGenre.append(indexPath[0])
}
}
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if (segue.identifier == "pushToMovies") {
if let VC = segue.destination as? FilteredSelection {
VC.selectedMovies = [selectedGenre]
}
}
}
func didRecieveDataUpdate(data: [[String]]) {
//=================here you need to update your tableView===================
}
deinit{
}
}