convenience methods

Author: tib

Sources/CollectionViewController.swift

@@ -12,14 +12,42 @@ open class CollectionViewController: UIViewController {
 
     @IBOutlet open weak var collectionView: UICollectionView!
 
+    // MARK: - source
+
     open var source: CollectionViewSource? = nil {
         didSet {
             self.source?.register(itemsFor: self.collectionView)
-
+            
             self.collectionView.dataSource = self.source
             self.collectionView.delegate = self.source
         }
     }
+    
+    // MARK: - init
+
+    public init() {
+        super.init(nibName: nil, bundle: nil)
+        
+        self.initialize()
+    }
+
+    required public init?(coder aDecoder: NSCoder) {
+        super.init(coder: aDecoder)
+        
+        self.initialize()
+    }
+    
+    public override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
+        super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
+        
+        self.initialize()
+    }
+    
+    open func initialize() {
+        // do nothing...
+    }
+    
+    // MARK: - view controller
 
     open override func loadView() {
         super.loadView()

Sources/CollectionViewSection.swift

@@ -34,3 +34,4 @@ open class CollectionViewSection {
         self.items.append(item)
     }
 }
+

Sources/CollectionViewSource.swift

@@ -34,6 +34,17 @@ open class CollectionViewSource: NSObject {
         super.init()
     }
 
+    // MARK: - public helper functions
+    public static func build(with grid: Grid = Grid(),
+                      sections: [[CollectionViewViewModelProtocol]],
+                      callback: CollectionViewCallback? = nil) -> CollectionViewSource {
+
+        let sections = sections.map { items in
+            return CollectionViewSection(grid: grid, header: nil, footer: nil, items: items)
+        }
+        return CollectionViewSource(grid: grid, sections: sections, callback: callback)
+    }
+    
     public func add(_ section: CollectionViewSection) {
         self.sections.append(section)
     }

Sources/CollectionViewViewModel.swift

@@ -23,9 +23,11 @@ open class CollectionViewViewModel<Cell, Data>: CollectionViewViewModelProtocol
     public var data: Data
     public var cell: CollectionViewCell.Type { return Cell.self }
     public var value: Any { return self.data }
+    public var callback: ((Data, IndexPath) -> Void)?
 
-    public init(_ data: Data) {
+    public init(_ data: Data, callback: ((Data, IndexPath) -> Void)? = nil) {
         self.data = data
+        self.callback = callback
         self.initialize()
     }
 
@@ -49,7 +51,8 @@ open class CollectionViewViewModel<Cell, Data>: CollectionViewViewModelProtocol
         guard let data = data as? Data else {
             return
         }
-        return self.callback(data: data, indexPath: indexPath)
+        self.callback(data: data, indexPath: indexPath)
+        self.callback?(data, indexPath)
     }
 
     // MARK: - API

Sources/Grid.swift

@@ -9,13 +9,18 @@
 import UIKit
 
 public extension UIEdgeInsets {
+
     public init(all value: CGFloat) {
         self.init(top: value, left: value, bottom: value, right: value)
     }
+
+    public init(horizontal: CGFloat, vertical: CGFloat) {
+        self.init(top: vertical, left: horizontal, bottom: vertical, right: horizontal)
+    }
 }
 
 public extension CGFloat {
-    
+
     public var evenRounded: CGFloat {
         var newValue = self.rounded(.towardZero)
         if newValue.truncatingRemainder(dividingBy: 2) == 1 {