GitHub - dtsvz/TreeTableViewAdapter: Adaptor to allow use UITableView as a tree

Implementation of Adapter pattern to add to UITableView supporting to show hierarchical data structures

Quick start:

Just conform your model to TreeNode protocol and it can be displayed in UITableView hierarchically
Implement custom TableViewCell
Declare Adapter property in your UIViewController
Implement UITableViewDelegate and UITableViewDatasource using Adapter

Usage

Comform your CellViewModel to TreeNode protocol as a FolderCellViewModel class

	public protocol TreeNode {
	    associatedtype T
	    var opened: Bool { get set }
	    var level: Int { get set }
	    var hasChildren: Bool { get }
	    func children <T where T: TreeNode> () -> [T]
	}

	class FolderCellViewModel: TreeNode {
	    typealias T = FolderCellViewModel
	    
	    init(ident: String) {
	        self.ident = ident
	    }

	    var ident: String
	    var name: String?
	    var subFolders = [FolderCellViewModel]()
	    
	    var opened: Bool = false
	    var level: Int = 0
	    
	    var hasChildren: Bool {
	        return subFolders.count > 0
	    }
	    
	    func children<FolderCellViewModel>() -> [FolderCellViewModel] {
	        return subFolders.flatMap { $0 as? FolderCellViewModel }
	    }
	}

Implement custom tableview cell

	class FolderTableViewCell: UITableViewCell {

	    @IBOutlet weak var label: UILabel!
	    @IBOutlet weak var folderImageView: UIImageView!
	    @IBOutlet weak var labelOffsetConstraint: NSLayoutConstraint!

	    var folderViewModel: FolderCellViewModel? { didSet { fill() } }

	    func fill() {
	        guard let folder = folderViewModel else { return }
	        label?.text = folder.name
	        labelOffsetConstraint.constant = CGFloat(folder.level * 16)
	        folderImageView.image = nil
	        backgroundColor = NodeStyles.leafColor
	        
	        guard folder.hasChildren else { return }
	        backgroundColor = NodeStyles.parentColor
	        folderImageView.image = folder.opened ? NodeStyles.openedImage : NodeStyles.closedImage
	    }
	}

	struct NodeStyles {
	    static let parentColor: UIColor = {
	        return UIColor.whiteColor()
	    }()
	    
	    static let leafColor: UIColor = {
	        return UIColor.whiteColor()
	    }()
	    
	    static let openedImage: UIImage? = {
	        return UIImage(named: "li_up")
	    }()
	    
	    static let closedImage: UIImage? = {
	        return UIImage(named: "li_down")
	    }()
	}

Declare Adapter

	var folderAdapter = TreeTableViewAdapter<FolderCellViewModel>()

Implement UITableViewDelegate and UITableViewDatasource using Adapter

	func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return folderAdapter.numberOfRows
    }
    
    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        guard let cellViewModel = folderAdapter.node(forIndexPath: indexPath),
              let cell = tableView.dequeueReusableCellWithIdentifier(cellViewModel.ident) as? FolderTableViewCell
        else { return cellNotFound() }
        
        cell.folderViewModel = cellViewModel
        
        return cell
    }
    
    func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
        guard let cellViewModel = folderAdapter.node(forIndexPath: indexPath) where cellViewModel.hasChildren else { return }
        folderAdapter.changeNodeState(inTableView: tableView, atIndexPath: indexPath)
    }

Set your model array to Adapter and reload data in UITableView

	folderAdapter.nodes = [YOUR_MODEL]
	tableView.reloadData()

Installation

Carthage:

github "dtsvz/TreeTableViewAdapter" == 1.0.1

Or you can manually add TreeTableViewAdapter.swift file to your project

Requirements

iOS 8.0
XCode 7.3
Swift 2.2