HTML5 Programming with JavaScript. by John Paul Mueller

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3 HTML5 Programming with JavaScript by John Paul Mueller

4 HTML5 Programming with JavaScript For Dummies Published by John Wiley & Sons, Inc. 111 River Street Hoboken, NJ Copyright 2013 by John Wiley & Sons, Inc., Hoboken, New Jersey Published simultaneously in Canada No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) , fax (978) Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) , fax (201) , or online at Trademarks: Wiley, the Wiley logo, For Dummies, the Dummies Man logo, A Reference for the Rest of Us!, The Dummies Way, Dummies Daily, The Fun and Easy Way, Dummies.com, Making Everything Easier, and related trade dress are trademarks or registered trademarks of John Wiley & Sons, Inc. and/or its affiliates in the United States and other countries, and may not be used without written permission. JavaScript is a registered trademark of Oracle America,Inc. All other trademarks are the property of their respective owners. John Wiley & Sons, Inc. is not associated with any product or vendor mentioned in this book. LIMIT OF LIABILITY/DISCLAIMER OF WARRANTY: THE PUBLISHER AND THE AUTHOR MAKE NO REPRESENTATIONS OR WARRANTIES WITH RESPECT TO THE ACCURACY OR COMPLETENESS OF THE CONTENTS OF THIS WORK AND SPECIFICALLY DISCLAIM ALL WARRANTIES, INCLUDING WITHOUT LIMITATION WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE. NO WARRANTY MAY BE CREATED OR EXTENDED BY SALES OR PROMOTIONAL MATERIALS. THE ADVICE AND STRATEGIES CONTAINED HEREIN MAY NOT BE SUITABLE FOR EVERY SITUATION. THIS WORK IS SOLD WITH THE UNDERSTANDING THAT THE PUBLISHER IS NOT ENGAGED IN RENDERING LEGAL, ACCOUNTING, OR OTHER PROFESSIONAL SERVICES. IF PROFESSIONAL ASSISTANCE IS REQUIRED, THE SERVICES OF A COMPETENT PROFESSIONAL PERSON SHOULD BE SOUGHT. NEITHER THE PUBLISHER NOR THE AUTHOR SHALL BE LIABLE FOR DAMAGES ARISING HEREFROM. THE FACT THAT AN ORGANIZATION OR WEBSITE IS REFERRED TO IN THIS WORK AS A CITATION AND/OR A POTENTIAL SOURCE OF FURTHER INFORMATION DOES NOT MEAN THAT THE AUTHOR OR THE PUBLISHER ENDORSES THE INFORMATION THE ORGANIZATION OR WEBSITE MAY PROVIDE OR RECOMMENDATIONS IT MAY MAKE. FURTHER, READERS SHOULD BE AWARE THAT INTERNET WEBSITES LISTED IN THIS WORK MAY HAVE CHANGED OR DISAPPEARED BETWEEN WHEN THIS WORK WAS WRITTEN AND WHEN IT IS READ. For general information on our other products and services, please contact our Customer Care Department within the U.S. at , outside the U.S. at , or fax For technical support, please visit Wiley publishes in a variety of print and electronic formats and by print-on-demand. Some material included with standard print versions of this book may not be included in e-books or in print-on-demand. If this book refers to media such as a CD or DVD that is not included in the version you purchased, you may download this material at For more information about Wiley products, visit Library of Congress Control Number: ISBN (pbk); ISBN (ebk); ISBN (ebk); ISBN (ebk) Manufactured in the United States of America

5 About the Author John Mueller is a freelance author and technical editor. He has writing in his blood, having produced 91 books and over 300 articles to date. The topics range from networking to artificial intelligence and from database management to heads-down programming. Some of his current books include Windows command-line references, books on VBA and Visio, several books on C#, and an IronPython programmer s guide. His technical editing skills have helped more than 63 authors refine the content of their manuscripts. John has provided technical editing services to both Data Based Advisor and Coast Compute magazines. He s also contributed articles to magazines like such as Software Quality Connection, DevSource, InformIT, SQL Server Professional, Visual C++ Developer, Hard Core Visual Basic, asp.netpro, Software Test and Performance, and Visual Basic Developer. Be sure to read John s blog at When John isn t working at the computer, you can find him outside in the garden, cutting wood, or generally enjoying nature. John also likes making wine and knitting. When not occupied with anything else, he makes glycerin soap and candles, which comes in handy for gift baskets. You can reach John on the Internet at John@JohnMuellerBooks.com. John is also setting up a website at Feel free to take a look and make suggestions on how he can improve it.

7 Dedication Dedicated to people who have given me hope and who have helped me realize new potential as an author; on the occasion of their 50th anniversary, Bill and Karen Bridges. Author s Acknowledgments Thanks to my wife, Rebecca, for working with me to get this book completed. I really don t know what I would have done without her help in researching and compiling some of the information that appears in this book. She also did a fine job of proofreading my rough draft. Rebecca keeps the house running while I m buried in work. Russ Mullen deserves thanks for his technical edit of this book. He greatly added to the accuracy and depth of the material you see here. Russ is always providing me with great URLs for new products and ideas. However, it s the testing Russ does that helps most. He s the sanity check for my work. Russ also has different computer equipment than mine, so he s able to point out flaws that I might not otherwise notice. Matt Wagner, my agent, deserves credit for helping me get the contract in the first place and taking care of all the details that most authors don t really consider. I always appreciate his assistance. It s good to know that someone wants to help. A number of people read all or part of this book to help me refine the approach, test the coding examples, and generally provide input that all readers wish they could have. These unpaid volunteers helped in ways too numerous to mention here. I especially appreciate the efforts of Eva Beattie, Glenn Russell, Osvaldo Téllez Almirall, and Gerald Wilson, Jr., who provided general input, read the entire book, and selflessly devoted themselves to this project. Finally, I would like to thank Kim Darosett, Katie Feltman, Virginia Sanders, Katie Crocker, and the rest of the editorial and production staff at Wiley for their assistance in bringing this book to print. It s always nice to work with such a great group of professionals.

8 Publisher s Acknowledgments We re proud of this book; please send us your comments at For other comments, please contact our Customer Care Department within the U.S. at , outside the U.S. at , or fax Some of the people who helped bring this book to market include the following: Acquisitions and Editorial Senior Project Editor: Kim Darosett Acquisitions Editor: Constance Santisteban Copy Editor: Virginia Sanders Technical Editor: Russ Mullen Editorial Manager: Leah Michael Editorial Assistant: Annie Sullivan Senior Editorial Assistant: Cherie Case Cover Photo: kertlis/istockphoto Composition Services Project Coordinator: Katherine Crocker Layout and Graphics: Amy Hassos, Joyce Haughey Proofreaders: Jessica Kramer, Lisa Stiers Indexer: Ty Koontz Publishing and Editorial for Technology Dummies Richard Swadley, Vice President and Executive Group Publisher Andy Cummings, Vice President and Publisher Mary Bednarek, Executive Acquisitions Director Mary C. Corder, Editorial Director Publishing for Consumer Dummies Kathleen Nebenhaus, Vice President and Executive Publisher Composition Services Debbie Stailey, Director of Composition Services

9 Table of Contents Introduction... 1 About This Book...1 What You Don t Have to Read...2 Foolish Assumptions...2 Conventions Used in This Book...3 How This Book Is Organized...3 Part I: Understanding the Basics of JavaScript...3 Part II: Speaking the JavaScript Language...4 Part III: Meeting JavaScript s Control Structures...4 Part IV: Interacting with Users and HTML...4 Part V: Extending JavaScript Further...5 Part VI: The Part of Tens...5 The companion Website...5 Icons Used in This Book...6 Where to Go from Here...6 Part I: Understanding the Basics of JavaScript... 9 Chapter 1: HTML, Say Hello to JavaScript Introducing JavaScript...12 Java and JavaScript aren t long-lost relatives...13 Recognizing the benefits of JavaScript...13 Seeing How JavaScript Fits into an HTML Document...16 Starting an HTML5 document...16 Understanding the alert( ) function...17 Using the <script> tag...18 Placing the code in the page heading...19 Relying on external files...20 Chapter 2: Assessing Tools of the Trade Researching Browsers and Their Debugging Tools...24 Catching up with Firefox...25 Meeting Google Chrome...29 Checking out native browsers: Internet Explorer or Safari...33 Checking browser and version...34

10 viii HTML5 Programming with JavaScript For Dummies Discovering Programs to Write JavaScript...36 Using a text editor...37 Using a dedicated editor...38 Hosting Your Site...41 Quickly looking at Web hosting...41 Using JavaScript from your computer...42 Testing your installation...46 Chapter 3: Integrating HTML5 and JavaScript Creating Simple Output...48 Writing to an HTML element...48 Creating direct document output...50 Avoiding potential problems with output...51 Working with JavaScript Statements...52 Understanding the dot syntax...52 Adding multiple statements to a single script...53 Defining basic code blocks...55 Understanding case sensitivity...55 Using white space effectively...55 Using the line continuation character...56 Writing Comments in JavaScript...57 Creating single-line comments...58 Creating multi-line comments...59 Preventing code execution by using comments...60 Alerting Visitors That JavaScript Has Something to Say...60 Using the <noscript> tag...60 Using styles...61 Part II: Speaking the JavaScript Language Chapter 4: Embracing JavaScript Variables Understanding Simple Variables...66 Seeing variables as storage bins...66 Declaring variables...67 Discovering variable types...68 Understanding undefined and null variables...70 Working with Booleans...71 Working with Numbers...72 Understanding the operators...73 Doing simple math...78 Changing number formats...80 Working with Text...83 Concatenating text...83 Changing word and letter formats...83

11 Table of Contents ix Working with Arrays...85 Creating an array...85 Accessing array members...86 Chapter 5: Working with Objects Defining Objects...90 Starting with the Object object...90 Understanding properties...92 Understanding methods...92 Understanding events...92 Using and Creating Objects...93 Using JavaScript objects...93 Building custom objects...98 Working with Object Literals Creating the name/value pairs Adding new name/value pairs Naming Variables and Objects Properly Chapter 6: Getting to Know the Standard JavaScript Objects Defining the Basic JavaScript Objects Understanding Object Understanding Number Understanding String Understanding Date Understanding RegExp Introducing the String Object Manipulating and searching strings Working with regular expressions Working with the Date Object Getting today s date right Calculating differences in dates Part III: Meeting JavaScript s Control Structures Chapter 7: Using Functions Using the Built-In Functions Working with the Math Object Building Custom Functions Reducing work using functions Passing parameters to functions Creating functions with a return value Creating functions with optional and required arguments Understanding variable scope Working with Private Properties and Methods...137

12 x HTML5 Programming with JavaScript For Dummies Chapter 8: Making Choices in JavaScript Understanding the Reasons for Applications to Make Decisions Deciding When to Use the if Statement Creating a simple if statement Deciding what else to do Nesting if statements Switching Between Choices Creating a basic switch Using the default option Chapter 9: Making the Rounds with Loops Discovering Loops Learning why loops are useful Running from the dangers of loops Creating for Loops Making your first for loop Using the break statement Using the continue statement Creating while Loops Using the basic while loop Using the do...while loop Examining Objects Using for/in Nesting Loops Chapter 10: Performing Error Handling Understanding Errors Defining an error source Defining the error types Catching Errors Using the try...catch block Understanding the Error object Throwing Errors Part IV: Interacting with Users and HTML Chapter 11: Understanding the Document Object Model Introducing the Document Object Model (DOM) Accessing Individual HTML Elements Modifying the output stream Affecting HTML content Changing attributes Considering Events Working with Styles...191

13 Table of Contents xi Working with Nodes Creating new elements Removing existing elements Chapter 12: Handling Events Introducing Events Performing basic event tasks Working with attributes Clicking to Create an Event Understanding the objects at your disposal Passing parameters to the event handler function Pressing a Key Creating Custom Events Working with the CustomEvent object Creating the custom event code Chapter 13: Connecting with Style: JavaScript and CSS Changing HTML Elements Working with HTML tags Working with heading styles Working with IDs Building Dynamic HTML Elements Animating and Positioning HTML Elements Creating JavaScript-Based Menus Designing the HTML Defining the styles Creating the JavaScript functions Chapter 14: Enhancing HTML5 Forms with JavaScript Revisiting the HTML5 Form Features Working with the new elements Working with the new controls Understanding the new attributes Accessing Form Elements Validating Forms Chapter 15: Interacting with Windows Working with Windows Determining window characteristics Changing window attributes Accessing the Screen Finding a Location Determining the current location Changing the location Searching History...247

14 xii HTML5 Programming with JavaScript For Dummies Working with Navigator Creating a Pop-Up Controlling line breaks Creating a modal dialog box Using Cookies Setting a cookie Getting a cookie Checking a cookie Part V: Extending JavaScript Further Chapter 16: Working with XML in JavaScript Introducing XML Gaining an overview of XML Understanding elements Understanding attributes Working through a basic file Displaying XML Using XSLT Validating XML Understanding the concept of well-formed Discovering XSD Loading XML with JavaScript Chapter 17: Cleaning Up the Web with AJAX Introducing AJAX Learning the benefits of AJAX Understanding how AJAX works Deciphering the XMLHttpRequest object Performing AJAX Tasks Using JavaScript Making AJAX Easier with jquery Chapter 18: Making JavaScript Easier with jquery Getting to Know the jquery Library Loading jquery from Google CDN Doing Things Easier with jquery Gathering elements with selectors Working with programmatically generated elements Revisiting arrays with jquery Interrogating an array Handling Events with jquery Understanding the event functionality Working with events...296

15 Table of Contents xiii Chapter 19: Using jquery to Handle AJAX Understanding the AJAX Object in jquery Considering the global AJAX event handlers Working with the helper functions Understanding the low-level interface Using shorthand methods Discovering Server-Side Programming Adding PHP support to your Apache server Testing your PHP configuration Creating the PHP script Retrieving Results from AJAX Calls Working with standard output Investigating the benefits of JSON Chapter 20: Animating the Web Getting to Know jquery UI Considering interactions Understanding the widgets Defining the effects Canvasing Your Web Page Understanding what the canvas does Creating a simple Google API application Part VI: The Part of Tens Chapter 21: Ten Incredible HTML5 and JavaScript Examples Creating an XML-Based Menu Creating an XML-Based Tabbed Interface Displaying a Slideshow Employing Custom Spinners Working with Timepickers Creating a Standardized Look with CSS Displaying a Category and Detail Data View Selecting Data Using a Calendar Developing a User-Configurable Interface Devising a Simple Survey Form Chapter 22: Ten Thoughts About the Future of Web Development Automating More Tasks Developing Applications That Run Anywhere Using Standards for Every Application Creating a Desktop Environment with a Browser...377

Windows 8 FOR QUICK REFERENCE

Windows 8 FOR QUICK REFERENCE Windows 8 FOR DUMmIES QUICK REFERENCE Windows 8 FOR DUMmIES QUICK REFERENCE by John Paul Mueller Windows 8 For Dummies Quick Reference Published by John Wiley & Sons, Inc. 111 River Street Hoboken, NJ