JavaScript & DHTML Cookbook, 2nd Edition

606 Pages·2007·4.859 MB·English

by  Danny Goodman

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JavaScript & DHTML Cookbook™
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SECOND EDITION
JavaScript & DHTML Cookbook™
Danny Goodman
Beijing • Cambridge • Farnham • Köln • Paris • Sebastopol • Taipei • Tokyo
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JavaScript and DHTML Cookbook™,Second Edition
by Danny Goodman
Copyright © 2007, 2003 Danny Goodman. All rights reserved.
Printed in the United States of America.
Published by O’Reilly Media, Inc., 1005 Gravenstein Highway North, Sebastopol, CA 95472.
O’Reilly books may be purchased for educational, business, or sales promotional use. Online editions
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corporate/institutional sales department: [phone] [email protected].
Editor: Tatiana Apandi Cover Designer: Karen Montgomery
Production Editor: Laurel R.T. Ruma Interior Designer: David Futato
Proofreader: Audrey Doyle Illustrators: RobertRomanoandJessamynRead
Indexer: Ellen Troutman Zaig
Printing History:
April 2003: First Edition.
August 2007: Second Edition.
Nutshell Handbook, the Nutshell Handbook logo, and the O’Reilly logo are registered trademarks of
O’ReillyMedia,Inc.TheCookbookseriesdesignations,JavaScriptandDHTMLCookbook,theimageof
a howler monkey, and related trade dress are trademarks of O’Reilly Media, Inc.
Manyofthedesignationsusedbymanufacturersandsellerstodistinguishtheirproductsareclaimedas
trademarks. Where those designations appear in this book, and O’Reilly Media, Inc. was aware of a
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Whileeveryprecautionhasbeentakeninthepreparationofthisbook,thepublisherandauthorassume
no responsibility for errors or omissions, or for damages resulting from the use of the information
contained herein.
This book uses RepKover™, a durable and flexible lay-flat binding.
ISBN-10: 0-596-51408-5
ISBN-13: 978-0-596-51408-2
[M]
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Table of Contents
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xiii
1. Strings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Concatenating (Joining) Strings 4
1.2 Improving String Handling Performance 6
1.3 Accessing Substrings 7
1.4 Changing String Case 8
1.5 Testing Equality of Two Strings 9
1.6 Testing String Containment Without Regular Expressions 11
1.7 Testing String Containment with Regular Expressions 13
1.8 Searching and Replacing Substrings 14
1.9 Using Special and Escaped Characters 15
1.10 Reading and Writing Strings for Cookies 17
1.11 Converting Between Unicode Values and String Characters 20
1.12 Encoding and Decoding URL Strings 21
1.13 Encoding and Decoding Base64 Strings 23
2. Numbers and Dates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2.1 Converting Between Numbers and Strings 31
2.2 Testing a Number’s Validity 33
2.3 Testing Numeric Equality 34
2.4 Rounding Floating-Point Numbers 35
2.5 Formatting Numbers for Text Display 36
2.6 Converting Between Decimal and Hexadecimal Numbers 39
2.7 Generating Pseudorandom Numbers 41
2.8 Calculating Trigonometric Functions 41
2.9 Creating a Date Object 42
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2.10 Calculating a Previous or Future Date 43
2.11 Calculating the Number of Days Between Two Dates 45
2.12 Validating a Date 47
3. Arrays and Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
3.1 Creating a Simple Array 54
3.2 Creating a Multidimensional Array 56
3.3 Converting Between Arrays and Strings 57
3.4 Doing Something with the Items in an Array 59
3.5 Sorting a Simple Array 61
3.6 Combining Arrays 63
3.7 Dividing Arrays 64
3.8 Creating a Custom Object 65
3.9 Simulating a Hash Table for Fast Array Lookup 69
3.10 Doing Something with a Property of an Object 71
3.11 Sorting an Array of Objects 72
3.12 Customizing an Object’s Prototype 74
3.13 Converting Arrays and Custom Objects to Strings 79
3.14 Using Objects to Reduce Naming Conflicts 82
4. Variables, Functions, and Flow Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
4.1 Creating a JavaScript Variable 85
4.2 Creating a Named Function 89
4.3 Nesting Named Functions 92
4.4 Creating an Anonymous Function 93
4.5 Delaying a Function Call 94
4.6 Branching Execution Based on Conditions 97
4.7 Handling Script Errors Gracefully 101
4.8 Improving Script Performance 103
5. Browser Feature Detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
5.1 Detecting the Browser Brand 113
5.2 Detecting an Early Browser Version 113
5.3 Detecting the Internet Explorer Version 115
5.4 Detecting the Mozilla Version 116
5.5 Detecting the Safari Version 118
5.6 Detecting the Opera Version 119
5.7 Detecting the Client Operating System 120
5.8 Detecting Object Support 121
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5.9 Detecting Object Property and Method Support 124
5.10 Detecting W3C DOM Standard Support 126
5.11 Detecting the Browser Written Language 127
5.12 Detecting Cookie Availability 128
5.13 Defining Browser- or Feature-Specific Links 129
5.14 Testing on Multiple Browser Versions 130
6. Managing Browser Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
6.1 Living with Browser Window Control Limitations 135
6.2 Setting the Main Window’s Size 136
6.3 Positioning the Main Window 137
6.4 Maximizing the Main Window 138
6.5 Creating a New Window 139
6.6 Bringing a Window to the Front 143
6.7 Communicating with a New Window 144
6.8 Communicating Back to the Main Window 147
6.9 Using Internet Explorer Modal/Modeless Windows 148
6.10 Simulating a Cross-Browser Modal Dialog Window 151
6.11 Simulating a Window with Layers 158
7. Managing Multiple Frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
7.1 Creating a Blank Frame in a New Frameset 178
7.2 Changing the Content of One Frame from Another 179
7.3 Changing the Content of Multiple Frames at Once 181
7.4 Replacing a Frameset with a Single Page 182
7.5 Avoiding Being “Framed” by Another Site 183
7.6 Ensuring a Page Loads in Its Frameset 184
7.7 Reading a Frame’s Dimensions 187
7.8 Resizing Frames 188
7.9 Setting Frameset Specifications Dynamically 192
8. Dynamic Forms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
8.1 Auto-Focusing the First Text Field 197
8.2 Performing Common Text Field Validations 198
8.3 Preventing Form Submission upon Validation Failure 204
8.4 Auto-Focusing an Invalid Text Field Entry 207
8.5 Using a Custom Validation Object 208
8.6 Changing a Form’s Action 213
8.7 Blocking Submissions from the Enter Key 214
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8.8 Advancing Text Field Focus with the Enter Key 215
8.9 Submitting a Form by an Enter Key Press in Any Text Box 216
8.10 Disabling Form Controls 217
8.11 Hiding and Showing Form Controls 219
8.12 Allowing Only Numbers (or Letters) in a Text Box 221
8.13 Auto-Tabbing for Fixed-Length Text Boxes 223
8.14 Changing select Element Content 224
8.15 Copying Form Data Between Pages 227
9. Managing Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
9.1 Equalizing the IE and W3C Event Models 236
9.2 Initiating a Process After the Page Loads 240
9.3 Appending Multiple Load Event Handlers 242
9.4 Determining the Coordinates of a Click Event 244
9.5 Preventing an Event from Performing Its Default Behavior 248
9.6 Blocking Duplicate Clicks 251
9.7 Determining Which Element Received an Event 252
9.8 Determining Which Mouse Button Was Pressed 254
9.9 Reading Which Character Key Was Typed 256
9.10 Reading Which Noncharacter Key Was Pressed 257
9.11 Determining Which Modifier Keys Were Pressed During an Event 260
9.12 Determining the Element the Cursor Rolled From/To 262
9.13 Synchronizing Sounds to Events 266
10. Page Navigation Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268
10.1 Loading a New Page or Anchor 271
10.2 Keeping a Page Out of the Browser History 273
10.3 Using a select Element for Navigation 274
10.4 Passing Data Between Pages via Cookies 276
10.5 Passing Data Between Pages via Frames 278
10.6 Passing Data Between Pages via URLs 280
10.7 Creating a Contextual (Right-Click) Menu 283
10.8 Creating Drop-Down Navigation Menus 291
10.9 Providing Navigation Trail Menus 305
10.10 Creating Expandable Menus 308
10.11 Creating Collapsible XML Menus 320
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11. Managing Style Sheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331
11.1 Assigning Style Sheet Rules to an Element Globally 333
11.2 Assigning Style Sheet Rules to a Subgroup of Elements 334
11.3 Assigning Style Sheet Rules to an Individual Element 336
11.4 Importing External Style Sheets 337
11.5 Importing Browser- or Operating System-Specific Style Sheets 338
11.6 Changing Imported Style Sheets After Loading 340
11.7 Enabling/Disabling Style Sheets 341
11.8 Toggling Between Style Sheets for an Element 342
11.9 Overriding a Style Sheet Rule 343
11.10 Turning Arbitrary Content into a Styled Element 344
11.11 Creating Center-Aligned Body Elements 345
11.12 Reading Effective Style Sheet Property Values 346
11.13 Forcing Recent Browsers into Standards-Compatibility Mode 348
12. Visual Effects for Stationary Content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351
12.1 Precaching Images 354
12.2 Swapping Images (Rollovers) 356
12.3 Reducing Rollover Image Downloads with JavaScript 358
12.4 Reducing Rollover Image Downloads with CSS 362
12.5 Dynamically Changing Image Sizes 366
12.6 Changing Text Style Properties 367
12.7 Offering Body Text Size Choices to Users 370
12.8 Creating Custom Link Styles 374
12.9 Changing Page Background Colors and Images 375
12.10 Hiding and Showing Elements 378
12.11 Adjusting Element Transparency 379
12.12 Creating Transition Visual Effects 381
12.13 Drawing Charts in the Canvas Element 385
13. Positioning HTML Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392
13.1 Making an Element Positionable in the Document Space 397
13.2 Connecting a Positioned Element to a Body Element 398
13.3 Controlling Positioning via a DHTML JavaScript Library 400
13.4 Deciding Between div and span Containers 407
13.5 Adjusting Positioned Element Stacking Order (Z-order) 409
13.6 Centering an Element on Top of Another Element 410
13.7 Centering an Element in a Window or Frame 412
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