Protocol Awesome

Transcript

1. Protocol awesome John Lin @johnlinvc
2. Protocol ਅੋ௒ແ༻ • େ֓୞༗Cocoa[Touch] ࠽။༻౸ሏ • Ṝഐࢠେ֓୞༗༻౸ UITableViewDelegate & UITableViewDataSource ࣕቮ • আྃ፤ိᙛdelegate ೭֎ෆ஌ಓؐೳװᅊ
3. UITableViewDataSource func numberOfSectionsInTableView(tableView: UITableView) -> Int { } func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int { } func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell { }
4. UITableViewDataSource class LiveTableSource:NSObject, UITableViewDataSource { lazy var items:[String] = ["a","b","c"] func numberOfSectionsInTableView(tableView: UITableView) -> Int { return 1 } func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int { return items.count }
5. UITableViewDataSource func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell { let ident = "cell" let cell = tableView.dequeueReusableCellWithIdentifier(ident) ?? UITableViewCell(style: .Default, reuseIdentifier: ident) let item = items[indexPath.row] cell.textLabel?.text = item return cell }
6. UITableViewDataSource var tableVC = UITableViewController(style: .Plain) var ltc = LiveTableSource() tableVC.tableView.dataSource = ltc XCPlaygroundPage.currentPage.liveView = tableVC
7. Protocol ਅੋ௒ແ༻௒޷༻ • հ໘(Interface) • Mixin(Trait) • Type Class
8. հ໘(Interface) • Ұݸ௨༻తߔ௨؅ಓ • ୞ࡏҙproperty & function ໊ࣈᢛಛ㐸ɼෆ؅መ࡞ • Delegate ሱԙṜҰྨ
9. Protocol protocol Animal : Creature { var age:Int { get } var name:String {get set} func move() }
10. SuperTextView • Ұݸೳⴺ႔ཧ֤छෆಉ෺݅తTextView • ݺڣappend(obj) ိ೺౦੢Ճ౸view ཫ
11. SuperTextView class SuperTextView: UITextView { func append(s:String) { text.appendContentsOf("\(s)\n") } } let superTextView = SuperTextView() superTextView.append("Hello world")
12. User struct User { let firstName:String let lastName:String }
13. SuperTextView class SuperTextView: UITextView { func append(s:String) { text.appendContentsOf("\(s)\n") } func append(u:User) { text.appendContentsOf("\(u.firstName) \(u.lastName) \n") } } let user = User(firstName: "John", lastName: "Lin") superTextView.append(user)
14. Post struct Post { let title:String let content:String }
15. SuperTextView class SuperTextView: UITextView { func append(s:String) { text.appendContentsOf("\(s)\n") } func append(u:User) { text.appendContentsOf("\(u.firstName) \(u.lastName) \n") } func append(p:Post) { text.appendContentsOf("\(p.title)\n\(p.content)\n") } } let post = Post(title: "hello", content: "world") superTextView.append(post)
16. ೗Ռ༗Ұඦଟछ౦੢ཁᰖࣔ䏆ʁ • बཁ༗Ұඦଟछෆಉతappend function
17. ೗Ռཁ၏ҰݸSuperLabel䏆ʁ • बಘ೺߶߶తҰඦଟछෳ੡աڈ • গվҰݸब။
18. ։ดݪཧ • Open Close Principle • ሣᎷॆ։์ɼሣमվ෧ด • ሜ޷తCode बผڈಈሏ
19. CustomStringConvertible public protocol CustomStringConvertible { /// A textual representation of `self`. var description: String { get } } String(5) String(2.333)
20. SuperTextView class SuperTextView: UITextView { func append2(any: CustomStringConvertible){ text.appendContentsOf("\(String(any))\n") } }
21. User struct User: CustomStringConvertible { let firstName:String let lastName:String var description: String { get { return "\(firstName) \(lastName)" } } }
22. Post struct Post : CustomStringConvertible { let title:String let content:String var description: String { get { return "\(title)\n\(content)" } } }
23. SuperTextView class SuperTextView: UITextView { func append2(any: CustomStringConvertible){ text.appendContentsOf("\(String(any))\n") } } let user = User(firstName: "John", lastName: "Lin") let post = Post(title: "hello", content: "world") let superTextView = SuperTextView() superTextView.append2("New") superTextView.append2(user) superTextView.append2(post)
24. հ໘ • ᩋfunction ࡏሏ֘ࡏత஍ํ • ೚Կత෺݅౎ՄҎ༗Ұᒬతհ໘ • ූ߹։߹ݪཧɼሣᎷॆ։์ɼሣमվ෧ด
25. Mixin(Trait) • ༗ᴍ૾ଟॏ៺ঝɼୠᔒ༗ࢮ๢ඛܗ໰୊ • ՄҎᩋ෺݅௚઀ಘ౸૬ಉతޭೳ
26. Extension • ՄҎ༻ိमվݱ༗తclass/struct • ૾Obj-C త Category Ұᒬ • ՄҎᩋprotocol ༗༬ઃత implementation
27. Extension extension Int { func next() -> Int { return self + 1 } } 2.next() //3
28. Mixin protocol Swimable { func swim() } extension Swimable { func swim(){ "i'm swimming" } } class Duck : Swimable { } Duck().swim() // "i'm swimming"
29. Loginable • ر๬ࡏ೚Կ஍ํ౎ՄҎݺڣొೖࢹᜬ • ر๬೚Կ஍ํ౎ՄҎፙ౸ݱࡏత࢖༻ऀࢿ㘤
30. User struct User { lazy var id:Int = 1 }
31. Loginable protocol Loginable { func showLogin() var currentUser:User { get } }
32. Loginable Extension extension Loginable { func showLogin() { print("called from \(self):please input username & password") } var currentUser:User { get { return User() } } }
33. Use Loginable in custom UIViewController class LoginView: UIViewController, Loginable { } let lv = LoginView() lv.showLogin() lv.currentUser
34. Use Loginable in custom UIButton class LoginButton : UIButton, Loginable { } let lb = LoginButton() lb.showLogin()
35. User Loginable in ANY UITableViewController extension UITableViewController : Loginable { } class CustomTableViewController : UITableViewController { } CustomTableViewController().showLogin()
36. Use Loginable on Int
 (੥໪໛㟩) extension Int : Loginable {} 5.showLogin()
37. Mixin • ݮগॏෳతఔࣜᛰ • ߱௿๨هվ๭ݸ஍ํతػ။
38. Type Class • հ໘࿨Mixin తࠞ߹ᱪ • ୞ཁClient Class ఏڙ෦㟨functionɼबೳఏڙڐଟ ᔤੜޭೳ • ៃయൣྫ: Comparable
39. Comparable • ୞ཁఏڙ < ࿨ == ӡࢉࢠɼबೳⴺࣗಈ㗞ੜ <=, >, >=, != struct Ranking : Comparable { let rank:Int } func == (lhs:Ranking, rhs: Ranking) -> Bool { return lhs.rank == rhs.rank } func < (lhs:Ranking, rhs: Ranking) -> Bool { return lhs.rank < rhs.rank } Ranking(rank: 3) <= Ranking(rank: 4) Ranking(rank: 3) > Ranking(rank: 4) Ranking(rank: 3) != Ranking(rank: 4)
40. Syncable • ՄҎኺServer ߋ৽ࢿྉ • ՄҎߋ৽Server ্తࢿྉ
41. Syncable protocol Syncable { var serverPath:NSURLComponents{ get } var jsonValue:String { set get } mutating func reload() func update() }
42. Syncable extension extension Syncable { func getFromPath(path:NSURLComponents) -> String { return "{\"id\":1,\"name\":\"John\"}" } func postPath(path: NSURLComponents) { print("posting to path:\(path)\n with data:\ (jsonValue)") } mutating func reload() { let json = getFromPath(serverPath) jsonValue = json } func update() { postPath(serverPath) } }
43. User class User: Syncable, CustomStringConvertible { lazy var name:String = "no one" lazy var id:Int = 1 var serverPath: NSURLComponents { get { return NSURLComponents(string: "http://localhost: 3000/users/\(id)")! } } var jsonValue: String { get { return "{\"id\":\(id),\"name\":\"\(name)\"}" } set { print("setting json value to \(newValue)") //set the id & name from json string } } }
44. Syncable ࢖༻ํ๏ var u = User() u.reload() // setting json value to {"id":1,"name":"John"} u.name = “John" u.update() // posting to path:<NSURLComponents 0x7fbd13a01ba0> {scheme = http, user = (null), password = (null), host = localhost, port = 3000, path = /users/1, query = (null), fragment = (null)} with data:{"id":1,"name":"John"}
45. Type Class • ᩋఔࣜߋ؆ܿ • ՄҎࣗಈ㗞ੜᔤ৳ޭೳ
46. Protocol ௒޷༻ • ՄҎ፤ိᙛ࡞௨༻తߔ௨؅ಓ • ՄҎ༗༬ઃመ࡞ɼఏڙଟॏ៺ঝൠతᏈՌ • ՄҎᩋ㟬తఔࣜߋ؆ܿɼߋ༰қमվɼߋෆ༰қग़ࡨ • Protocol > ៺ঝɼҰݸClass ୞ೳ៺ঝҰݸ Classɼ ୠੋՄҎ༗኷ଟ protocol
47. Code • https://github.com/johnlinvc/protocol-awesome
48. Q&A