Design Patterns

More documents

Recommendations

Info

x ■CONTENTS ■CHAPTER 8 The Bridge Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 Example: Event Listeners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 Other Examples of Bridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 Bridging Multiple Classes Together . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 Example: Building an XHR Connection Queue . . . . . . . . . . . . . . . . . . . . . . 111 Including the Core Utilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 Including an Observer System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 Developing the Queue Skeleton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 Implementing the Queue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 Where Have Bridges Been Used? . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 When Should the Bridge Pattern Be Used?. . . . . . . . . . . . . . . . . . . . . . . . . 122 Benefits of the Bridge Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 Drawbacks of the Bridge Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 ■CHAPTER 9 The Composite Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 The Structure of the Composite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 Using the Composite Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 Example: Form Validation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 Putting It All Together . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 Adding Operations to FormItem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 Adding Classes to the Hierarchy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 Adding More Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 Example: Image Gallery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 Benefits of the Composite Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 Drawbacks of the Composite Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 ■CHAPTER 10 The Facade Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 Some Facade Functions You Probably Already Know About. . . . . . . . . . . 141 JavaScript Libraries As Facades . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 Facades As Convenient Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 Example: Setting Styles on HTML Elements . . . . . . . . . . . . . . . . . . . . . . . . 144 Example: Creating an Event Utility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 General Steps for Implementing the Facade Pattern. . . . . . . . . . . . . . . . . 147 When Should the Facade Pattern Be Used? . . . . . . . . . . . . . . . . . . . . . . . . 148 Benefits of the Facade Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 Drawbacks of the Facade Pattern. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
■CONTENTS xi ■CHAPTER 11 The Adapter Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 Characteristics of an Adapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 Adapting Existing Implementations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 Example: Adapting One Library to Another . . . . . . . . . . . . . . . . . . . . . . . . . 150 Example: Adapting an Email API . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 Wrapping the Webmail API in an Adapter . . . . . . . . . . . . . . . . . . . . . 157 Migrating from fooMail to dedMail . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 When Should the Adapter Pattern Be Used?. . . . . . . . . . . . . . . . . . . . . . . . 158 Benefits of the Adapter Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 Drawbacks of the Adapter Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 ■CHAPTER 12 The Decorator Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 The Structure of the Decorator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 The Role of the Interface in the Decorator Pattern. . . . . . . . . . . . . . 163 The Decorator Pattern vs. the Composite Pattern . . . . . . . . . . . . . . 163 In What Ways Can a Decorator Modify Its Component? . . . . . . . . . . . . . . 164 Adding Behavior After a Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 Adding Behavior Before a Method . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 Replacing a Method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 Adding New Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 The Role of the Factory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 Function Decorators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172 When Should the Decorator Pattern Be Used?. . . . . . . . . . . . . . . . . . . . . . 173 Example: Method Profiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 Benefits of the Decorator Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 Drawbacks of the Decorator Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 ■CHAPTER 13 The Flyweight Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 The Structure of the Flyweight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 Example: Car Registrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 Intrinsic and Extrinsic State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 Instantiation Using a Factory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 Extrinsic State Encapsulated in a Manager. . . . . . . . . . . . . . . . . . . . 182 Managing Extrinsic State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 Example: Web Calendar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 Converting the Day Objects to Flyweights. . . . . . . . . . . . . . . . . . . . . 185 Where Do You Store the Extrinsic Data? . . . . . . . . . . . . . . . . . . . . . . 186
Page 1: The EXPERT’s VOIce ® in Web Deve
Page 4 and 5: Pro JavaScript Design Patterns Cop
Page 7: Contents at a Glance About the Auth
Page 10 and 11: viii ■CONTENTS ■CHAPTER 3 Encap
Page 14 and 15: xii ■CONTENTS Example: Tooltip Ob
Page 17: About the Authors ■ROSS HARMES is
Page 21: Acknowledgments Thanks to our intre
Page 24 and 25: xxii ■INTRODUCTION them. This typ
Page 26 and 27: xxiv ■INTRODUCTION behaviors on m
Page 28 and 29: xxvi ■INTRODUCTION • extend(sub
Page 31 and 32: CHAPTER 1 ■ ■ ■ Expressive Ja
Page 33 and 34: CHAPTER 1 ■ EXPRESSIVE JAVASCRIPT
Page 39 and 40: CHAPTER 2 ■ ■ ■ Interfaces Th
Page 41 and 42: CHAPTER 2 ■ INTERFACES 13 Java us
Page 43 and 44: CHAPTER 2 ■ INTERFACES 15 /* inte
Page 45 and 46: CHAPTER 2 ■ INTERFACES 17 } if(!i
Page 47 and 48: CHAPTER 2 ■ INTERFACES 19 The Int
Page 49 and 50: CHAPTER 2 ■ INTERFACES 21 1. Incl
Page 51: CHAPTER 2 ■ INTERFACES 23 Pattern
Page 54 and 55: 26 CHAPTER 3 ■ ENCAPSULATION AND
Page 62 and 63:
34 CHAPTER 3 ■ ENCAPSULATION AND
Page 64 and 65:
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
42 CHAPTER 4 ■ INHERITANCE Classi
Page 72 and 73:
44 CHAPTER 4 ■ INHERITANCE having
Page 74 and 75:
46 CHAPTER 4 ■ INHERITANCE Instea
Page 76 and 77:
48 CHAPTER 4 ■ INHERITANCE var co
Page 78 and 79:
50 CHAPTER 4 ■ INHERITANCE It is
Page 80 and 81:
52 CHAPTER 4 ■ INHERITANCE Exampl
Page 82 and 83:
54 CHAPTER 4 ■ INHERITANCE To cre
Page 84 and 85:
56 CHAPTER 4 ■ INHERITANCE this.s
Page 86 and 87:
58 CHAPTER 4 ■ INHERITANCE this.f
Page 88 and 89:
Page 90 and 91:
Page 93 and 94:
CHAPTER 5 ■ ■ ■ The Singleton
Page 95 and 96:
CHAPTER 5 ■ THE SINGLETON PATTERN
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
Page 107 and 108:
Page 109 and 110:
Page 111 and 112:
CHAPTER 6 ■ ■ ■ Chaining In t
Page 113 and 114:
CHAPTER 6 ■ CHAINING 85 Since all
Page 115 and 116:
CHAPTER 6 ■ CHAINING 87 (function
Page 117 and 118:
CHAPTER 6 ■ CHAINING 89 Using Cal
Page 119:
PART 2 ■ ■ ■ Design Patterns
Page 122 and 123:
94 CHAPTER 7 ■ THE FACTORY PATTER
Page 124 and 125:
Page 126 and 127:
Page 128 and 129:
100 CHAPTER 7 ■ THE FACTORY PATTE
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
Page 138 and 139:
110 CHAPTER 8 ■ THE BRIDGE PATTER
Page 140 and 141:
Page 142 and 143:
Page 144 and 145:
Page 146 and 147:
Page 148 and 149:
Page 150 and 151:
Page 153 and 154:
CHAPTER 9 ■ ■ ■ The Composite
Page 155 and 156:
CHAPTER 9 ■ THE COMPOSITE PATTERN
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
CHAPTER 10 ■ ■ ■ The Facade P
Page 171 and 172:
CHAPTER 10 ■ THE FACADE PATTERN 1
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
CHAPTER 11 ■ ■ ■ The Adapter
Page 179 and 180:
CHAPTER 11 ■ THE ADAPTER PATTERN
Page 181 and 182:
asyncRequest: function() { function
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
CHAPTER 12 ■ ■ ■ The Decorato
Page 189 and 190:
CHAPTER 12 ■ THE DECORATOR PATTER
Page 191 and 192:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
Page 203 and 204:
Page 205:
Page 208 and 209:
180 CHAPTER 13 ■ THE FLYWEIGHT PA
Page 210 and 211:
Page 212 and 213:
Page 214 and 215:
Page 216 and 217:
Page 218 and 219:
Page 220 and 221:
Page 222 and 223:
Page 225 and 226:
CHAPTER 14 ■ ■ ■ The Proxy Pa
Page 227 and 228:
CHAPTER 14 ■ THE PROXY PATTERN 19
Page 229 and 230:
Page 231 and 232:
Page 233 and 234:
Page 235 and 236:
Page 237 and 238:
Page 239 and 240:
Page 241 and 242:
Page 243 and 244:
CHAPTER 15 ■ ■ ■ The Observer
Page 245 and 246:
CHAPTER 15 ■ THE OBSERVER PATTERN
Page 247 and 248:
Page 249 and 250:
Page 251:
Page 254 and 255:
226 CHAPTER 16 ■ THE COMMAND PATT
Page 256 and 257:
Page 258 and 259:
Page 260 and 261:
Page 262 and 263:
Page 264 and 265:
Page 266 and 267:
Page 268 and 269:
Page 270 and 271:
Page 272 and 273:
Page 274 and 275:
246 CHAPTER 17 ■ THE CHAIN OF RES
Page 276 and 277:
Page 278 and 279:
Page 280 and 281:
Page 282 and 283:
Page 284 and 285:
Page 286 and 287:
Page 288 and 289:
Page 290 and 291:
Page 292 and 293:
264 ■INDEX classical inheritance,
Page 294 and 295:
266 ■INDEX as objects, 6-8, 37 pr
Page 296 and 297:
268 ■INDEX performance issues, 12
Page 298:
Offer valid through 06/08.
show all

Design Patterns

Create successful ePaper yourself

Delete template?

Save as template?