Quick Start for using UICollectionView

DemoUICollectionViewController.swift

//  Created by Damien Bell on 6/2/16.
//  Copyright © 2016 Damien Bell. All rights reserved.
//

import UIKit

class DemoUICollectionViewController: UIViewController,
                                   UICollectionViewDataSource,
                                   UICollectionViewDelegateFlowLayout{
    
    
    @IBOutlet weak var collectionView: UICollectionView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        collectionView.contentInset = UIEdgeInsets(top: 68.0, left: 0, bottom: 20.0, right: 0)
        
        //register cells
        collectionView.registerNib(UINib(nibName: "CustomCell", bundle: nil), forCellWithReuseIdentifier: "CustomCell")
        
        //create layout
        let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
        layout.sectionInset = UIEdgeInsets(top: 8.0, left: 0.0, bottom: 0.0, right: 0.0)
        
        layout.minimumLineSpacing = 0.0
        layout.minimumInteritemSpacing = 0.0
        
        collectionView.collectionViewLayout = layout;
        collectionView.dataSource = self;
        collectionView.delegate = self;
    }

    // MARK: - UICollectionViewDataSource
    func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
        return 0
    }
    
    func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int{
        
        return 0
    }
    
    func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell{
        let cell = collectionView.dequeueReusableCellWithReuseIdentifier("CustomCell", forIndexPath: indexPath) //as CustomCellSubclass
        return cell
    }
    
    // MARK: - UICollectionViewDelegateFlowLayout
    func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize{

        return CGSizeZero
    }
    
    func shouldInvalidateLayoutForBoundsChange(newBounds: CGRect) -> Bool{
        return true
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}