An abstract wrapper class for DZNEmptyDataSet that makes showing simple empty states easy. Untested in Swift 3 yet

AbstractEmptyDataSetSource.swift

//
//  AbstractEmptyDataSource.swift
//  ABSocialMediaManager
//
//  Created by Aron Bury on 14/09/2015.
//  Copyright © 2015 Aron Bury. All rights reserved.
//

import Foundation
import DZNEmptyDataSet

enum EmptyDataSourceState {
    case ReadyToSearch
    case NoResults
    case NetworkError
}

protocol EmptyDataSourceResponder: class {
    func dataSourceShouldRefresh()
}

class AbstractEmptyDataSetSource: NSObject, DZNEmptyDataSetSource, DZNEmptyDataSetDelegate {
    
    let dataView: UIScrollView
    private(set) var state: EmptyDataSourceState
    weak var responder: EmptyDataSourceResponder?
    
    init(dataView: UIScrollView) {
        self.dataView = dataView
        state = EmptyDataSourceState.ReadyToSearch
        super.init()
        dataView.emptyDataSetSource = self
        dataView.emptyDataSetDelegate = self
    }
    
    convenience init(dataView: UIScrollView, responder: EmptyDataSourceResponder?, state: EmptyDataSourceState) {
        self.init(dataView: dataView)
        self.responder = responder
        self.state = state
    }
    
    func updateState(state: EmptyDataSourceState) {
        self.state = state
        dataView.reloadEmptyDataSet()
    }
    
    //MARK: Empty DataSet Source
    func titleForEmptyDataSet(scrollView: UIScrollView!) -> NSAttributedString! {
        return NSAttributedString(string: "Find your clients")
    }
    
    func descriptionForEmptyDataSet(scrollView: UIScrollView!) -> NSAttributedString! {
        return NSAttributedString(string: "Enter a search term to search for Instagram Users")
    }
    
    func imageForEmptyDataSet(scrollView: UIScrollView!) -> UIImage! {
        return nil
    }
    
    func buttonTitleForEmptyDataSet(scrollView: UIScrollView!, forState state: UIControlState) -> NSAttributedString! {
        switch self.state {
        case .NetworkError:
            return NSAttributedString(string: "Try Again")
        default:
            return nil
        }
    }
    
    //MARK: Empty DataSet Delegate
    func emptyDataSetDidTapButton(scrollView: UIScrollView!) {
        if let _responder = responder {
            _responder.dataSourceShouldRefresh()
        }
    }
    
    //MARK: Subclass overides
    internal func iconSize() -> CGSize {
        let screenHeight = UIScreen.mainScreen().bounds.height
        var iconSize: CGFloat = 80
        if screenHeight > 480 {
            iconSize = 150
        }
        return CGSizeMake(iconSize, iconSize)
    }
}