lucianboboc · May 5, 2019 16:07 · May 1, 2019 · May 1, 2019 · May 1, 2019 · May 1, 2019
diff --git a/pat.swift b/pat.swift
@@ -1,19 +1,61 @@
-protocol SomeProtocol {
+class PersonCell: UICollectionViewCell {
+    @IBOutlet weak var firstLabel: UILabel!
+    @IBOutlet weak var secondLabel: UILabel!
+}
+
+struct Person {
+    let firstName: String
+    let lastName: String
+}
+
+protocol PersonsDatasourceProtocol: class {
     associatedtype Model
     associatedtype Cell: UICollectionViewCell
 
     func didSelect(model: Model)
-    func indexPath(for sender: Cell) -> IndexPath?
-    func reloadData()
+    func indexPath(for cell: Cell) -> IndexPath?
+    func reloadUI()
 }
 
-class SomeDatasource<Model, Cell: UICollectionViewCell>: UICollectionViewDataSource, UICollectionViewDelegate {
-    var delegate: SomeProtocol<Model, Cell>?   // PAT not allowed to be used as type
+class PersonsDatasource<Model, Cell: UICollectionViewCell>: UICollectionViewDataSource, UICollectionViewDelegate {
+
+    var models: [Model] = [] // will be loaded from an api
+    weak var delegate: PersonsDatasourceProtocol<Model, Cell>?  // not possible
 
     typealias CellConfigurator = (Model, Cell) -> Void
-    private let cellConfigurator: CellConfigurator  // injected in init, called in cellForItem(at:)
+    private let cellConfigurator: CellConfigurator
+
+    init(cellConfigurator: @escaping CellConfigurator) {
+        self.cellConfigurator = cellConfigurator
+    }
+
+    // datasource and delegate methods
+    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
+        let model = self.models[indexPath.item]
+        delegate?.didSelect(model: model)
+    }
+}
+
+class PersonsViewController: UIViewController, PersonsDatasourceProtocol {
+    typealias Model = Person
+    typealias Cell = PersonCell
+
+    @IBOutlet weak var collectionView: UICollectionView!
+
+    let datasource = PersonsDatasource<Model, Cell>(cellConfigurator: { model, cell in
+        cell.firstLabel.text = model.firstName
+        cell.secondLabel.text = model.lastName
+    })
+
+    func didSelect(model: Model) {
+        // do something with the model ...
+    }
 
-    init(reuseIdentifier: String, cellConfigurator: CellConfigurator) { ... }
+    func indexPath(for cell: Cell) -> IndexPath? {
+        return collectionView.indexPath(for: cell)
+    }
 
-    // collection datasource and delegate methods
+    func reloadUI() {
+        collectionView.reloadData()
+    }
 }
diff --git a/pat.swift b/pat.swift
@@ -1,6 +1,6 @@
 protocol SomeProtocol {
     associatedtype Model
-    associatedtype Cell
+    associatedtype Cell: UICollectionViewCell
 
     func didSelect(model: Model)
     func indexPath(for sender: Cell) -> IndexPath?

diff --git a/gistfile1.txt → pat.swift b/gistfile1.txt → pat.swift
diff --git a/gistfile1.txt b/gistfile1.txt
@@ -0,0 +1,19 @@
+protocol SomeProtocol {
+    associatedtype Model
+    associatedtype Cell
+
+    func didSelect(model: Model)
+    func indexPath(for sender: Cell) -> IndexPath?
+    func reloadData()
+}
+
+class SomeDatasource<Model, Cell: UICollectionViewCell>: UICollectionViewDataSource, UICollectionViewDelegate {
+    var delegate: SomeProtocol<Model, Cell>?   // PAT not allowed to be used as type
+
+    typealias CellConfigurator = (Model, Cell) -> Void
+    private let cellConfigurator: CellConfigurator  // injected in init, called in cellForItem(at:)
+
+    init(reuseIdentifier: String, cellConfigurator: CellConfigurator) { ... }
+
+    // collection datasource and delegate methods
+}