Swift μ-framework for efficient array diffs, collection observation and data source implementation.
cd {PROJECT_ROOT_DIRECTORY} curl "https://raw.githubusercontent.com/alexdrone/Buffer/master/bin/dist.zip" > dist.zip && unzip dist.zip && rm dist.zip;Drag Buffer.framework in your project and add it as an embedded binary.
If you use xcodegen add the framework to your project.yml like so:
targets: YOUR_APP_TARGET: ... dependencies: - framework: PATH/TO/YOUR/DEPS/Buffer.frameworkIf you are using CocoaPods:
Add the following to your Podfile:
pod 'Buffer'If you are using Carthage:
To install Carthage, run (using Homebrew):
$ brew update $ brew install carthageThen add the following line to your Cartfile:
github "alexdrone/Buffer" "master" Buffer is designed to be very granular and has APIs with very different degrees of abstraction.
You can initialize and use Buffer in the following way.
import Buffer class MyClass: BufferDelegate { lazy var buffer: Buffer<Foo> = { // The `sort` and the `filter` closure are optional - they are a convenient way to map the src array. let buffer = Buffer(initialArray: self.elements, sort: { $0.bar > $1.bar }, filter: { $0.isBaz }) buffer.delegate = self }() var elements: [Foo] = [Foo]() { didSet { // When the elements are changed the buffer object will compute the difference and trigger // the invocation of the delegate methods. // The `synchronous` and `completion` arguments are optional. self.buffer.update(with: newValues, synchronous: false, completion: nil) } } //These methods will be called when the buffer has changedd. public func buffer(willChangeContent buffer: BufferType) { //e.g. self.tableView?.beginUpdates() } public func buffer(didDeleteElementAtIndices buffer: BufferType, indices: [UInt]) { //e.g. Remove rows from a tableview } public func buffer(didInsertElementsAtIndices buffer: BufferType, indices: [UInt]) { } public func buffer(didChangeContent buffer: BufferType) { } public func buffer(didChangeElementAtIndex buffer: BufferType, index: UInt) { } public func buffer(didMoveElement buffer: BufferType, from: UInt, to: UInt) { } public func buffer(didChangeAllContent buffer: BufferType) { } }One of the main use cases for Buffer is probably to apply changes to a TableView or a CollectionView. Buffer provides 2 adapter classes that implement the BufferDelegate protocol and automatically perform the required changes on the target tableview/collectionview when required.
import Buffer class MyClass: UITableViewController { lazy var buffer: Buffer<Foo> = { // The `sort` and the `filter` closure are optional - they are convenient way to map the src array. let buffer = Buffer(initialArray: self.elements, sort: { $0.bar > $1.bar }, filter: { $0.isBaz }) buffer.delegate = self }() var elements: [Foo] = [Foo]() { didSet { // When the elements are changed the buffer object will compute the difference and trigger // the invocation of the delegate methods. // The `synchronous` and `completion` arguments are optional. self.buffer.update(with: newValues, synchronous: false, completion: nil) } } let adapter: TableViewDiffAdapter<Foo>! init() { super.init() self.adapter = TableViewDiffAdapter(buffer: self.buffer, view: self.tableView) // Additionaly you can let the adapter be the datasource for your table view by passing a cell // configuration closure to the adpater. adapter.useAsDataSource { (tableView, object, indexPath) -> UITableViewCell in let cell = tableView.dequeueReusableCellWithIdentifier("MyCell") cell?.textLabel?.text = object.foo return cell } } } Another convenient way to use Buffer is through the Buffer.TableView class. This abstraction allows for the tableView to reconfigure itself when its state (the elements) change.
import Buffer class ViewController: UIViewController { lazy var tableView: TableView<FooModel> = { let tableView = TableView<FooModel>() return tableView }() lazy var elements: [ListItem<FooModel>] = { var elements = [ListItem<FooModel>]() for _ in 0...100 { // AnyListItem wraps the data and the configuration for every row in the tableview. let item = ListItem(type: UITableViewCell.self, container: self.tableView, model: FooModel(text: "Foo"))) { cell, model in cell.textLabel?.text = model.text } elements.append(item) } return elements }() override func viewDidLayoutSubviews() { self.tableView.frame = self.view.bounds } override func viewDidLoad() { super.viewDidLoad() self.view.addSubview(self.tableView) self.tableView.elements = self.elements } } Check the demo out to learn more about Buffer.
- Diff algorithm from IGListKit/IGListDiff