Pro JavaScript Design Patterns

Contents......Page 6
About the Authors......Page 13
About the Technical Reviewer......Page 14
Acknowledgments......Page 15
Introduction......Page 16
PART 1: Object-Oriented JavaScript......Page 22
The Flexibility of JavaScript......Page 23
Functions As First-Class Objects......Page 26
The Mutability of Objects......Page 28
Design Patterns in JavaScript......Page 29
Summary......Page 30
What Is an Interface?......Page 31
How Other Object-Oriented Languages Handle Interfaces......Page 32
Emulating an Interface in JavaScript......Page 34
The Interface Implementation for This Book......Page 38
The Interface Class......Page 39
Summary......Page 43
The Information Hiding Principle......Page 44
Basic Patterns......Page 45
More Advanced Patterns......Page 54
Drawbacks to Using Encapsulation......Page 58
Summary......Page 59
Why Do You Need Inheritance?......Page 60
Classical Inheritance......Page 61
Prototypal Inheritance......Page 64
Inheritance and Encapsulation......Page 68
Mixin Classes......Page 69
Example: Edit-in-Place......Page 71
When Should Inheritance Be Used?......Page 81
Summary......Page 82
The Basic Structure of the Singleton......Page 83
Namespacing......Page 84
A Singleton As a Wrapper for Page-Specific Code......Page 86
A Singleton with Private Members......Page 88
Lazy Instantiation......Page 93
Branching......Page 96
Example: Creating XHR Objects with Branching......Page 97
Benefits of the Singleton Pattern......Page 99
Summary......Page 100
CHAPTER 6: Chaining......Page 101
The Structure of a Chain......Page 102
Building a Chainable JavaScript Library......Page 104
Using Callbacks to Retrieve Data from Chained Methods......Page 107
Summary......Page 108
PART 2: Design Patterns......Page 109
The Simple Factory......Page 110
The Factory Pattern......Page 113
Example: XHR Factory......Page 116
Example: RSS Reader......Page 121
Benefits of the Factory Pattern......Page 124
Summary......Page 125
Example: Event Listeners......Page 126
Other Examples of Bridges......Page 127
Example: Building an XHR Connection Queue......Page 128
When Should the Bridge Pattern Be Used?......Page 139
Summary......Page 140
CHAPTER 9: The Composite Pattern......Page 141
Using the Composite Pattern......Page 142
Example: Form Validation......Page 143
Example: Image Gallery......Page 152
Drawbacks of the Composite Pattern......Page 155
Summary......Page 156
Some Facade Functions You Probably Already Know About......Page 157
JavaScript Libraries As Facades......Page 158
Facades As Convenient Methods......Page 159
Example: Setting Styles on HTML Elements......Page 160
Example: Creating an Event Utility......Page 162
General Steps for Implementing the Facade Pattern......Page 163
Summary......Page 164
Characteristics of an Adapter......Page 165
Example: Adapting One Library to Another......Page 166
Example: Adapting an Email API......Page 168
Summary......Page 174
The Structure of the Decorator......Page 175
In What Ways Can a Decorator Modify Its Component?......Page 180
The Role of the Factory......Page 185
Function Decorators......Page 188
Example: Method Profiler......Page 189
Drawbacks of the Decorator Pattern......Page 192
Summary......Page 193
Example: Car Registrations......Page 194
Example: Web Calendar......Page 198
Example: Tooltip Objects......Page 201
Storing Instances for Later Reuse......Page 205
When Should the Flyweight Pattern Be Used?......Page 207
Benefits of the Flyweight Pattern......Page 208
Summary......Page 209
The Structure of the Proxy......Page 211
Example: Page Statistics......Page 215
General Pattern for Wrapping a Web Service......Page 219
Example: Directory Lookup......Page 220
General Pattern for Creating a Virtual Proxy......Page 224
Drawbacks of the Proxy Pattern......Page 227
Summary......Page 228
Example: Newspaper Delivery......Page 229
Building an Observer API......Page 232
Observers in Real Life......Page 234
Example: Animation......Page 235
Event Listeners Are Also Observers......Page 236
Summary......Page 237
The Structure of the Command......Page 238
Types of Command Objects......Page 241
Example: Menu Items......Page 243
Example: Undo and Logging......Page 248
When to Use the Command Pattern......Page 255
Drawbacks of the Command Pattern......Page 256
Summary......Page 257
The Structure of the Chain of Responsibility......Page 258
Passing on Requests......Page 264
Implementing a Chain of Responsibility in an Existing Hierarchy......Page 267
When Should the Chain of Responsibility Pattern Be Used?......Page 268
Example: Image Gallery Revisited......Page 269
Benefits of the Chain of Responsibility Pattern......Page 274
Summary......Page 275
C......Page 276
D......Page 277
F......Page 278
L......Page 279
P......Page 280
S......Page 281
X......Page 282