Programming HTML5 Applications

1. The Web As Application Platform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Adding Power to Web Applications 1
Developing Web Applications 2
JavaScript’s Triumph 4
2. The Power of JavaScript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Nonblocking I/O and Callbacks 7
Lambda Functions Are Powerful 9
Closures 11
Functional Programming 13
Prototypes and How to Expand Objects 16
Expanding Functions with Prototypes 18
Currying and Object Parameters 21
Array Iteration Operations 22
You Can Extend Objects, Too 25
3. Testing JavaScript Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
QUnit 30
A Simple Example 30
Testing with QUnit 32
Selenium 33
Selenium Commands 35
Constructing Tests with the Selenium IDE 38
Automatically Running Tests 39
Selenese Command Programming Interface 42
Running QUnit from Selenium 45
Selenium RC and a Test Farm 46

4. Local Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
The localStorage and sessionStorage Objects 50
Using localStorage in ExtJS 53
Offline Loading with a Data Store 55
Storing Changes for a Later Server Sync 57
JQuery Plug-ins 58
DSt 58
jStore 59
5. IndexedDB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Adding and Updating Records 64
Adding Indexes 65
Retrieving Data 65
Deleting Data 66
6. Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Blobs 67
Working with Files 69
Uploading Files 70
Drag-and-Drop 71
Putting It All Together 71
Filesystem 73
7. Taking It Offline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Introduction to the Manifest File 75
Structure of the Manifest File 76
Updates to the Manifest File 77
Events 79
Debugging Manifest Files 81
8. Splitting Up Work Through Web Workers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Web Worker Use Cases 87
Graphics 87
Maps 88
Using Web Workers 88
The Worker Environment 88
Worker Communication 89
Web Worker Fractal Example 90
Testing and Debugging Web Workers 96
A Pattern for Reuse of Multithread Processing 97
Libraries for Web Workers 101

9. Web Sockets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
The Web Sockets Interface 105
Setting Up a Web Socket 105
Web Socket Example 106
Web Socket Protocol 108
Ruby Event Machine 108
Erlang Yaws 109
10. New Tags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Tags for Applications 111
Accessibility Through WAI-ARIA 112
Microdata 113
New Form Types 114
Audio and Video 115
Canvas and SVG 115
Geolocation 116
New CSS 116
Appendix: JavaScript Tools You Should Know . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121