Professional Ajax, 2nd Edition

Introduction xv

Chapter 1: What Is Ajax? 1

Ajax Is Born 2

The Evolution of the Web 2

JavaScript 2

Frames 3

The Hidden Frame Technique 3

Dynamic HTML and the DOM 3

Iframes 4

XMLHttp 4

The Real Ajax 5

Ajax Principles 6

Technologies behind Ajax 6

Who Is Using Ajax? 7

Google Suggest 7

Gmail 8

Google Maps 9

A9 10

Yahoo! News 11

Bitflux Blog 12

Confusion and Controversy 13

Ajax and Web 2.0 14

Summary 15

Chapter 2: Ajax Basics 17

HTTP Primer 17

HTTP Requests 18

HTTP Responses 20

Ajax Communication Techniques 21

The Hidden Frame Technique 21

XMLHttp Requests (XHR) 37

Ajax with Images 50

Dynamic Script Loading 59

Cache Control 63

Summary 63

Chapter 3: Ajax Patterns 65

Communication Control Patterns 65

Predictive Fetch 66

Page Preloading Example 66

Submission Throttling 74

Incremental Form Validation Example 76

Incremental Field Validation Example 82

Periodic Refresh 85

New Comment Notifier Example 86

Multi-Stage Download 90

Additional Information Links Example 91

Fallback Patterns 93

Cancel Pending Requests 94

Try Again 96

Summary 97

Chapter 4: Ajax Libraries 99

The Yahoo! Connection Manager 99

Setup 99

Basic Requests 100

The Callback Object 100

Monitoring and Managing Requests 104

Form Interaction 104

File Uploads 105

GET Example 106

POST Example 107

Additional Features 108

Limitations 108

Prototype 109

The Ajax.Request Object 109

The Options Object 109

GET Example 112

POST Example 113

The Ajax.Updater Object 113

The Ajax.Responders Object 115

Advantages and Disadvantages 117

jQuery 117

Simple jQuery Expressions 117

Executing GET Requests 118

GET Example 119

The $.post() Method 120

POST Example 120

The load() Method 122

The $.ajax() Method 123

The ajaxStart() and ajaxStop() Methods 124

Limitations 124

Summary 125

Chapter 5: Request Management 127

Priority Queues 127

The RequestManager Object 131

Request Description Objects 132

Queuing Requests 133

Sending Requests 134

Cancelling Requests 139

Age-Based Promotion 141

Handling Ajax Patterns 142

Using RequestManager 145

Summary 148

Chapter 6: XML, XPath, and XSLT 149

XML Support in Browsers 149

XML DOM in IE 149

XML in Other Browsers 159

Cross-Browser XML 162

A Basic XML Example 163

XPath Support in Browsers 170

Introduction to XPath 170

XPath in IE 172

Working with Namespaces 173

XPath in Other Browsers 175

Working with a Namespace Resolver 177

Cross-Browser XPath 178

XSL Transformation Support in Browsers 179

Introduction to XSLT 180

XSLT in IE 182

XSLT in Other Browsers 187

Cross-Browser XSLT 189

Best Picks Revisited 189

Summary 192

Chapter 7: Syndication with RSS and Atom 193

RSS 193

RSS 0.91 194

RSS 1.0 195

RSS 2.0 196

Atom 196

XParser 197

The xparser Namespace 197

Retrieving the Data 198

The Abstract Classes 198

Creating a News Ticker 210

The Server-Side Component 210

The Client-Side Component 211

Styling the News 221

Using the News Ticker Widget 222

Web Search with RSS 223

The Server-Side Component 224

The Client-Side Component 225

Customizing the Web Search Widget 232

Using the Web Search Widget 234

Summary 235

Chapter 8: JSON 237

What Is JSON? 237

Array Literals 237

Object Literals 238

Mixing Literals 239

JSON Syntax 240

JSON Encoding/Decoding 241

JSON versus XML 242

Server-Side JSON Tools 243

JSON-PHP 243

Other Tools 245

Creating an Autosuggest Textbox 246

Functionality Overview 246

The HTML 247

The Database Table 249

The Architecture 249

The Classes 250

The AutoSuggest Control 250

The Suggestion Provider 267

The Server-Side Component 268

The Client-Side Component 270

Summary 272

Chapter 9: Comet 273

HTTP Streaming 274

Request Delays 274

File Modification Example 276

Using Iframes 277

Browser-Specific Approaches 282

Server-Sent DOM Events 291

Connection Management 296

Server-Side Support 297

Summary 298

Chapter 10: Maps and Mashups 299

The Rise of Mashups 300

Geocoding 300

Geocoding Web Sites 300

Geocoding Services 301

Google Maps API 301

How Does It Work? 301

Getting Started 302

Google Maps Basics 303

Controls 304

Moving the Map 306

Info Windows 306

Events 311

Map Overlays 313

Additional Information 321

Yahoo! Maps API 321

Getting Started 321

Yahoo! Maps Basics 322

Controls 324

Moving the Map 325

Smart Windows 326

Events 327

Map Overlays 328

Address Lookup 334

Additional Information 334

Other Mapping APIs 335

Summary 335

Chapter 11: Ajax Debugging Tools 337

The Problem 337

FireBug 338

Installation and Setup 338

The Interface 339

XHR Logging 340

Ajax Debugging with FireBug 341

FireBug Limitations 342

Microsoft Fiddler 342

Installation and Setup 343

The Interface 344

HTTP Breakpoints 347

Ajax Debugging with Fiddler 348

Summary 349

Chapter 12: Web Site Widgets 351

Creating a Weather Widget 351

The Weather.com SDK 351

The Server-Side Component 352

The Client-Side Component 361

Getting Data from the Server 361

Customizing the Weather Widget 362

Setting Up the Weather Widget as an Application 366

Adding the Weather Widget to the Web Page 370

Watching Stocks 371

Getting Yahoo! Finance Information 371

The Stock Quote Proxy 372

Client Component: The AjaxStockWatcher Class 376

Customizing the Stock Quotes 385

Using the Stock Watcher Widget 387

Creating a Site Search Widget 388

The Server-Side Component 389

The Client-Side Component 398

Customizing the Site Search Widget 403

Adding the Site Search Widget to a Page 405

Summary 406

Chapter 13: Ajax Frameworks 407

JPSpan 407

Using JPSpan 408

JPSpan Example 412

Summary of JPSpan 415

DWR 416

Using DWR 416

DWR Example 419

More about dwr.xml 424

Summary of DWR 427

Ajax.NET Professional 427

Using Ajax.NET Professional 427

Type Conversion 429

Session Access 430

Ajax.NET Professional Example 431

Summary of Ajax.NET Professional 436

Summary 436

Chapter 14: ASP.NET AJAX Extensions (Atlas) 437

Requirements and Setup 438

The AJAX Client Library 438

Accessing the Client Tools with ASP.NET 438

Accessing the Client Tools without ASP.NET 439

Using Classes 440

Writing Code with the ASP.NET AJAX Library 440

Using Controls 446

Making HTTP Requests 451

The UpdatePanel Control 455

Adding the UpdatePanel to the Page 455

Adding Content to the UpdatePanel 456

Triggering an Update 457

Finishing Up 458

SiteSearch Revisited 459

The User Interface 459

Getting Started 460

Declaring the Form 460

Performing the Search 462

Clearing the Results 467

Handling Errors 467

Hooking Up the Events 468

Summary 470

Chapter 15: Case Study: FooReader.NET 471

The Client Components 472

The User Interface 472

Styling the Interface 475

Driving the UI 481

The Server Application 495

Possible Paradigms 495

Implementation 496

Setup and Testing 506

Summary 508

Chapter 16: Case Study: AjaxMail 509

Requirements 509

Architecture 510

Resources Used 510

The Database Tables 511

The Configuration File 512

The AjaxMailbox Class 513

Performing Actions 535

The User Interface 541

The Folder View 544

Read View 546

Compose View 548

Layout 550

Tying It All Together 550

Helper Functions 552

The Mailbox 553

Callback Functions 571

Event Handlers 573

The Last Step 573

Summary 574

Appendix A: Licenses for Libraries and Frameworks 575

Index 583

GNU General Public License 600