Merge pull request ochococo#20 from codestergit/MementoPattern

Added Memento Pattern
CityFire · Oct 24, 2014 · 12d218c · 12d218c
2 parents 49a71a0 + afd9772
commit 12d218c
Show file tree

Hide file tree

Showing 21 changed files with 307 additions and 132 deletions.
diff --git a/Design-Patterns.playground.zip b/Design-Patterns.playground.zip
diff --git a/Design-Patterns.playground/Documentation/section-59.html b/Design-Patterns.playground/Documentation/section-59.html
@@ -13,8 +13,7 @@
   <section class="section">
     <h2 id="-iterator">🚧  Iterator</h2>
 <h2 id="-mediator">🚧  Mediator</h2>
-<h2 id="-memento">🚧  Memento</h2>
-<h2 id="-observer">👓 Observer</h2>
+<h2 id="-memento">💾 Memento</h2>
 
   </section>
 </div>

diff --git a/Design-Patterns.playground/Documentation/section-61.html b/Design-Patterns.playground/Documentation/section-61.html
@@ -11,7 +11,7 @@
 <body>
 <div class="content-wrapper">
   <section class="section">
-    <p><strong>Usage:</strong></p>
+    <p><strong><em>Usage:</em></strong></p>
 
   </section>
 </div>

diff --git a/Design-Patterns.playground/Documentation/section-63.html b/Design-Patterns.playground/Documentation/section-63.html
@@ -11,7 +11,7 @@
 <body>
 <div class="content-wrapper">
   <section class="section">
-    <h2 id="-state">🐉 State</h2>
+    <h2 id="-observer">👓 Observer</h2>
 
   </section>
 </div>

diff --git a/Design-Patterns.playground/Documentation/section-67.html b/Design-Patterns.playground/Documentation/section-67.html
@@ -11,7 +11,7 @@
 <body>
 <div class="content-wrapper">
   <section class="section">
-    <h2 id="-strategy">💡 Strategy</h2>
+    <h2 id="-state">🐉 State</h2>
 
   </section>
 </div>

diff --git a/Design-Patterns.playground/Documentation/section-71.html b/Design-Patterns.playground/Documentation/section-71.html
@@ -11,7 +11,7 @@
 <body>
 <div class="content-wrapper">
   <section class="section">
-    <h2 id="-visitor">🏃 Visitor</h2>
+    <h2 id="-strategy">💡 Strategy</h2>
 
   </section>
 </div>

diff --git a/Design-Patterns.playground/Documentation/section-75.html b/Design-Patterns.playground/Documentation/section-75.html
@@ -11,9 +11,7 @@
 <body>
 <div class="content-wrapper">
   <section class="section">
-    <h1 id="info">Info</h1>
-<p>🍺 Playground generated with: <a href="https://github.com/jas/swift-playground-builder">Swift Playground Builder</a> by <a href="http://twitter.com/jasonsandmeyer">@jasonsandmeyer</a></p>
-<p>🚀 How to generate playground (+zip) from this README: <a href="https://github.com/ochococo/Design-Patterns-In-Swift/blob/master/GENERATE.markdown">GENERATE.markdown</a></p>
+    <h2 id="-visitor">🏃 Visitor</h2>
 
   </section>
 </div>

diff --git a/Design-Patterns.playground/Documentation/section-77.html b/Design-Patterns.playground/Documentation/section-77.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <title>Section 78</title>
+  <meta id="xcode-display" name="xcode-display" content="render">
+  <meta name="apple-mobile-web-app-capable" content="yes">
+  <meta name="viewport" content="width=device-width, maximum-scale=1.0">
+  <link rel="stylesheet" type="text/css" href="stylesheet.css">
+</head>
+<body>
+<div class="content-wrapper">
+  <section class="section">
+    <p><strong>Usage:</strong></p>
+
+  </section>
+</div>
+</body>
+</html>
diff --git a/Design-Patterns.playground/Documentation/section-79.html b/Design-Patterns.playground/Documentation/section-79.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <title>Section 80</title>
+  <meta id="xcode-display" name="xcode-display" content="render">
+  <meta name="apple-mobile-web-app-capable" content="yes">
+  <meta name="viewport" content="width=device-width, maximum-scale=1.0">
+  <link rel="stylesheet" type="text/css" href="stylesheet.css">
+</head>
+<body>
+<div class="content-wrapper">
+  <section class="section">
+    <h1 id="info">Info</h1>
+<p>🍺 Playground generated with: <a href="https://github.com/jas/swift-playground-builder">Swift Playground Builder</a> by <a href="http://twitter.com/jasonsandmeyer">@jasonsandmeyer</a></p>
+<p>🚀 How to generate playground (+zip) from this README: <a href="https://github.com/ochococo/Design-Patterns-In-Swift/blob/master/GENERATE.markdown">GENERATE.markdown</a></p>
+
+  </section>
+</div>
+</body>
+</html>
diff --git a/Design-Patterns.playground/contents.xcplayground b/Design-Patterns.playground/contents.xcplayground
@@ -153,5 +153,13 @@
         </code>
         <documentation relative-path="section-75.html">
         </documentation>
+        <code source-file-name="section-76.swift">
+        </code>
+        <documentation relative-path="section-77.html">
+        </documentation>
+        <code source-file-name="section-78.swift">
+        </code>
+        <documentation relative-path="section-79.html">
+        </documentation>
     </sections>
 </playground>
diff --git a/Design-Patterns.playground/section-60.swift b/Design-Patterns.playground/section-60.swift
@@ -1,15 +1,35 @@
-class StepCounter {
-    var totalSteps: Int = 0 {
-
-        willSet(newTotalSteps) {
-            println("About to set totalSteps to \(newTotalSteps)")
-        }
-
-        didSet {
-
-            if totalSteps > oldValue  {
-                println("Added \(totalSteps - oldValue) steps")
-            }
-        }
+typealias Memento = Dictionary<NSObject, AnyObject>
+
+/**
+* Originator
+*/
+class GameState {
+    var gameLevel: Int = 1
+    var playerScore: Int = 0
+
+    func saveToMemeto() -> Memento {
+        return ["gameLevel": gameLevel, "playerScore": playerScore] 
+    }
+
+    func restoreFromMemeto(memento: Memento) {
+        gameLevel = memento["gameLevel"]! as Int
+        playerScore = memento["playerScore"]! as Int
+    }
+}
+
+/**
+* Caretaker
+*/
+class CheckPoint {
+    class func saveState(memento: Memento, keyName: String = "gameState") {
+        let defaults:NSUserDefaults = NSUserDefaults.standardUserDefaults()
+        defaults.setObject(memento, forKey: keyName)
+        defaults.synchronize()
+    }
+
+    class func restorePreviousState(keyName: String = "gameState") -> Memento {
+        let defaults:NSUserDefaults = NSUserDefaults.standardUserDefaults()
+
+        return defaults.objectForKey(keyName) as Memento
     }
 }
diff --git a/Design-Patterns.playground/section-62.swift b/Design-Patterns.playground/section-62.swift
@@ -1,10 +1,26 @@
-let stepCounter = StepCounter()
-stepCounter.totalSteps = 200
-// About to set totalSteps to 200
-// Added 200 steps
-stepCounter.totalSteps = 360
-// About to set totalSteps to 360
-// Added 160 steps
-stepCounter.totalSteps = 896
-// About to set totalSteps to 896
-// Added 536 steps
+var gameState = GameState()
+gameState.gameLevel = 2
+gameState.playerScore = 200
+
+// Saves state: {gameLevel 2 playerScore 200}
+CheckPoint.saveState(gameState.saveToMemeto())
+
+gameState.gameLevel = 3
+gameState.gameLevel = 250
+
+// Restores state: {gameLevel 2 playerScore 200}
+gameState.restoreFromMemeto(CheckPoint.restorePreviousState())
+
+gameState.gameLevel = 4
+
+// Saves state - gameState2: {gameLevel 4 playerScore 200}
+CheckPoint.saveState(gameState.saveToMemeto(), keyName: "gameState2")
+
+gameState.gameLevel = 5
+gameState.playerScore = 300
+
+// Saves state - gameState3: {gameLevel 5 playerScore 300}
+CheckPoint.saveState(gameState.saveToMemeto(), keyName: "gameState3")
+
+// Restores state - gameState2: {gameLevel 4 playerScore 200}
+gameState.restoreFromMemeto(CheckPoint.restorePreviousState(keyName: "gameState2"))
diff --git a/Design-Patterns.playground/section-64.swift b/Design-Patterns.playground/section-64.swift
@@ -1,42 +1,15 @@
-class Context {
-	private var state: State = UnauthorizedState()
-
-    var isAuthorized: Bool {
-        get { return state.isAuthorized(self) }
-    }
-
-    var userId: String? {
-        get { return state.userId(self) }
+class StepCounter {
+    var totalSteps: Int = 0 {
+
+        willSet(newTotalSteps) {
+            println("About to set totalSteps to \(newTotalSteps)")
+        }
+
+        didSet {
+
+            if totalSteps > oldValue  {
+                println("Added \(totalSteps - oldValue) steps")
+            }
+        }
     }
-
-	func changeStateToAuthorized(#userId: String) {
-		state = AuthorizedState(userId: userId)
-	}
-
-	func changeStateToUnauthorized() {
-		state = UnauthorizedState()
-	}
-
-
-}
-
-protocol State {
-	func isAuthorized(context: Context) -> Bool
-	func userId(context: Context) -> String?
-}
-
-class UnauthorizedState: State {
-	func isAuthorized(context: Context) -> Bool { return false }
-
-	func userId(context: Context) -> String? { return nil }
-}
-
-class AuthorizedState: State {
-	let userId: String
-
-	init(userId: String) { self.userId = userId }
-
-	func isAuthorized(context: Context) -> Bool { return true }
-
-	func userId(context: Context) -> String? { return userId }
 }
diff --git a/Design-Patterns.playground/section-66.swift b/Design-Patterns.playground/section-66.swift
@@ -1,6 +1,10 @@
-let context = Context()
-(context.isAuthorized, context.userId)
-context.changeStateToAuthorized(userId: "admin")
-(context.isAuthorized, context.userId) // now logged in as "admin"
-context.changeStateToUnauthorized()
-(context.isAuthorized, context.userId)
+let stepCounter = StepCounter()
+stepCounter.totalSteps = 200
+// About to set totalSteps to 200
+// Added 200 steps
+stepCounter.totalSteps = 360
+// About to set totalSteps to 360
+// Added 160 steps
+stepCounter.totalSteps = 896
+// About to set totalSteps to 896
+// Added 536 steps
diff --git a/Design-Patterns.playground/section-68.swift b/Design-Patterns.playground/section-68.swift
@@ -1,28 +1,42 @@
-protocol PrintStrategy {
-    func printString(string: String) -> String
-}
-
-class Printer {
+class Context {
+	private var state: State = UnauthorizedState()
 
-    let strategy: PrintStrategy
-
-    func printString(string: String) -> String {
-        return self.strategy.printString(string)
+    var isAuthorized: Bool {
+        get { return state.isAuthorized(self) }
     }
-    
-    init(strategy: PrintStrategy) {
-        self.strategy = strategy
+
+    var userId: String? {
+        get { return state.userId(self) }
     }
+
+	func changeStateToAuthorized(#userId: String) {
+		state = AuthorizedState(userId: userId)
+	}
+
+	func changeStateToUnauthorized() {
+		state = UnauthorizedState()
+	}
+
+
 }
 
-class UpperCaseStrategy : PrintStrategy {
-    func printString(string:String) -> String {
-        return string.uppercaseString
-    }
+protocol State {
+	func isAuthorized(context: Context) -> Bool
+	func userId(context: Context) -> String?
 }
 
-class LowerCaseStrategy : PrintStrategy {
-    func printString(string:String) -> String {
-        return string.lowercaseString
-    }
+class UnauthorizedState: State {
+	func isAuthorized(context: Context) -> Bool { return false }
+
+	func userId(context: Context) -> String? { return nil }
+}
+
+class AuthorizedState: State {
+	let userId: String
+
+	init(userId: String) { self.userId = userId }
+
+	func isAuthorized(context: Context) -> Bool { return true }
+
+	func userId(context: Context) -> String? { return userId }
 }
diff --git a/Design-Patterns.playground/section-70.swift b/Design-Patterns.playground/section-70.swift
@@ -1,5 +1,6 @@
-var lower = Printer(strategy:LowerCaseStrategy())
-lower.printString("O tempora, o mores!")
-
-var upper = Printer(strategy:UpperCaseStrategy())
-upper.printString("O tempora, o mores!")
+let context = Context()
+(context.isAuthorized, context.userId)
+context.changeStateToAuthorized(userId: "admin")
+(context.isAuthorized, context.userId) // now logged in as "admin"
+context.changeStateToUnauthorized()
+(context.isAuthorized, context.userId)