Workaround for: Generic Array DataSource

gistfile1.swift

public class ArrayDataSource<CellType: UIView, ItemType> {
	private var items: [ItemType]
	private var cellReuseIdentifier: String
	private var configureClosure: (CellType, ItemType) -> Void
	private var proxy: DataSourceProxy!
	private unowned var view: UIView
	
	public init(view: UIView, items: [ItemType], cellReuseIdentifier: String, configureClosure: (CellType, ItemType) -> Void) {
		self.items = items
		self.cellReuseIdentifier = cellReuseIdentifier
		self.configureClosure = configureClosure
		self.view = view
		
		configureDataSource()
	}
	
	private func configureDataSource() {
		assert(view as? UITableView || view as? UICollectionView, "Passed view must be of type UITableView or UICollectionView")
		
		self.proxy = DataSourceProxy(self)
		
		if let tableView = view as? UITableView {
			tableView.dataSource = proxy
		}
		
		if let collectionView = view as? UICollectionView {
			collectionView.dataSource = proxy
		}
	}
	
	public func itemAtIndexPath(indexPath: NSIndexPath) -> ItemType {
		return self.items[indexPath.row] as ItemType
	}
	
	public func configureCell(cell: CellType, atIndexPath indexPath:NSIndexPath) {
		let item = itemAtIndexPath(indexPath)
		self.configureClosure(cell, item)
	}
	
	func numberOfSectionsInTableView(tableView: UITableView!) -> Int {
		if items.count <= 0 {
			return 0
		}
		
		return 1
	}
	
	func tableView(tableView: UITableView!, numberOfRowsInSection section: Int) -> Int {
		return self.items.count
	}
	
	func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! {
		let cell = tableView.dequeueReusableCellWithIdentifier(self.cellReuseIdentifier, forIndexPath: indexPath) as CellType
		configureCell(cell, atIndexPath: indexPath)
		
		return cell as UITableViewCell
	}
	
	// MARK: - UICollectionViewDataSource
	
	func collectionView(collectionView: UICollectionView!, numberOfItemsInSection section: Int) -> Int {
		return items.count
	}
	
	func numberOfSectionsInCollectionView(collectionView: UICollectionView!) -> Int {
		if items.count <= 0 {
			return 0
		}
		
		return 1
	}
	
	func collectionView(collectionView: UICollectionView!, cellForItemAtIndexPath indexPath: NSIndexPath!) -> UICollectionViewCell! {
		var cell = collectionView.dequeueReusableCellWithReuseIdentifier(cellReuseIdentifier, forIndexPath: indexPath) as CellType
		configureCell(cell, atIndexPath: indexPath)
		
		return cell as UICollectionViewCell
	}
	
	private class DataSourceProxy: NSObject, UITableViewDataSource, UICollectionViewDataSource {
		private unowned var dataSource: ArrayDataSource<UIView, Any>
		
		init(_ dataSource: AnyObject) {
			self.dataSource = dataSource as ArrayDataSource<UIView, Any>
		}
		
		// MARK: UITableViewDataSource
		
		func numberOfSectionsInTableView(tableView: UITableView!) -> Int {
			return dataSource.numberOfSectionsInTableView(tableView)
		}
		
		func tableView(tableView: UITableView!, numberOfRowsInSection section: Int) -> Int {
			return dataSource.tableView(tableView, numberOfRowsInSection: section)
		}
		
		func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! {
			return dataSource.tableView(tableView, cellForRowAtIndexPath: indexPath)
		}
		
		// MARK: - UICollectionViewDataSource
		
		func collectionView(collectionView: UICollectionView!, numberOfItemsInSection section: Int) -> Int {
			return dataSource.collectionView(collectionView, numberOfItemsInSection: section)
		}
		
		func numberOfSectionsInCollectionView(collectionView: UICollectionView!) -> Int {
			return dataSource.numberOfSectionsInCollectionView(collectionView)
		}
		
		func collectionView(collectionView: UICollectionView!, cellForItemAtIndexPath indexPath: NSIndexPath!) -> UICollectionViewCell! {
			return dataSource.collectionView(collectionView, cellForItemAtIndexPath: indexPath)
		}
	}
}

@ksmandersen Thank you for the great example. It's very helpful for me. I'm just wondering if we get rid of the DataSourceProxy class and make the ArrayDataSource is the dataSource for the table/collectionView. would it cause any problems?

public class ArrayDataSource<CellType: UIView, ItemType>: NSObject, UITableViewDataSource, UICollectionViewDataSource {
    private var items: [ItemType]
    private var cellReuseIdentifier: String
    private var configureClosure: (CellType, ItemType) -> Void
//  private var proxy: UITableViewDataSource!
    private unowned var view: UIView

    public init(view: UIView, items: [ItemType], cellReuseIdentifier: String, configureClosure: (CellType, ItemType) -> Void) {
        self.items = items
        self.cellReuseIdentifier = cellReuseIdentifier
        self.configureClosure = configureClosure
        self.view = view
        super.init()

        self.configureDataSource()
    }

    private func configureDataSource() {
        assert(view is UITableView || view is UICollectionView, "Passed view must be of type UITableView or UICollectionView")
//      self.proxy = DataSourceProxy<CellType,ItemType>(self)

        if let tableView = view as? UITableView {
            tableView.dataSource = self
        }

        if let collectionView = view as? UICollectionView {
                collectionView.dataSource = self
        }
    }

    public func itemAtIndexPath(indexPath: NSIndexPath) -> ItemType {
        return self.items[indexPath.row] as ItemType
    }

    public func configureCell(cell: CellType, atIndexPath indexPath: NSIndexPath) {
        let item = itemAtIndexPath(indexPath)
        self.configureClosure(cell, item)
    }

    @objc public func numberOfSectionsInTableView(tableView: UITableView) -> Int {
        if items.count <= 0 {
            return 0
        }

        return 1
    }

    public func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        let count = items.count
        return count
    }

    public func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCellWithIdentifier(self.cellReuseIdentifier, forIndexPath: indexPath) as! CellType
        configureCell(cell, atIndexPath: indexPath)

        return cell as! UITableViewCell
    }

    // MARK: - UICollectionViewDataSource

    public func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return items.count
    }

    @objc public func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
        if items.count <= 0 {
            return 0
        }

        return 1
    }

    public func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCellWithReuseIdentifier(cellReuseIdentifier, forIndexPath: indexPath) as! CellType
        configureCell(cell, atIndexPath: indexPath)

        return cell as! UICollectionViewCell
    }
}