CuuDuongThanCong.com https://fb.com/tailieudientucntt Reliable JavaScript® Lawrence D Spencer Seth H Richards CuuDuongThanCong.com https://fb.com/tailieudientucntt Reliable JavaScript® Published by John Wiley & Sons, Inc 10475 Crosspoint Boulevard Indianapolis, IN 46256 www.wiley.com Copyright © 2015 by John Wiley & Sons, Inc., Indianapolis, Indiana Published simultaneously in Canada ISBN: 978-1-119-02872-7 ISBN: 978-1-119-02873-4 (ebk) ISBN: 978-1-119-02874-1 (ebk) Manufactured in the United States of America 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, 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the author shall be liable for damages arising herefrom The fact that an organization or Web site 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 United States at (877) 762-2974, outside the United States at (317) 572-3993 or fax (317) 572-4002 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 http://booksupport.wiley.com For more information about Wiley products, visit www.wiley.com Library of Congress Control Number: 2015941920 Trademarks: Wiley, the Wiley logo, Wrox, the Wrox logo, Programmer to Programmer, 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 CuuDuongThanCong.com https://fb.com/tailieudientucntt We dedicate this book to all JavaScript developers who work hard to hone their craft You are making the world a more beautiful place CuuDuongThanCong.com https://fb.com/tailieudientucntt CREDITS PROJECT EDITOR Christina Haviland TECHNICAL EDITORS Keith Pepin John Peloquin PRODUCTION MANAGER Kathleen Wisor COPY EDITOR Nancy Rapoport MANAGER OF CONTENT DEVELOPMENT & ASSEMBLY Mary Beth Wakefield MARKETING DIRECTOR David Mayhew MARKETING MANAGER Carrie Sherrill PROFESSIONAL TECHNOLOGY & STRATEGY DIRECTOR Barry Pruett BUSINESS MANAGER Amy Knies ASSOCIATE PUBLISHER Jim Minatel PROJECT COORDINATOR, COVER Brent Savage PROOFREADER Nancy Carrasco INDEXER Johnna VanHoose Dinse COVER DESIGNER Wiley COVER IMAGE © Getty Images/Andrew Rich CuuDuongThanCong.com https://fb.com/tailieudientucntt CuuDuongThanCong.com https://fb.com/tailieudientucntt ABOUT THE AUTHORS LARRY SPENCER is Vice President of Application Development at ScerIS, a software and services company in Sudbury, Massachusetts He and his team create browser-based applications in AngularJS, with a C#/Web API/SQL Server back end Larry's 35-year career has included stints programming in COBOL, C, C++, C#, and even mainframe assembly language, but he says JavaScript is the most fun A frequent speaker at Code Camps and other gatherings, Larry enjoys sharing his love of software with the development community You can find his blog at http://FascinatedWithSoftware.com Larry's outside interests include philosophy, chess, and classical guitar He lives in Marlborough, Massachusetts SETH RICHARDS has been crafting software professionally since 2002 He got his start programming embedded devices for the bar and nightclub industry and transitioned to web application development in 2007 He has worked on numerous web-based applications ranging from an enterpriseclass geographic information system–centric physical asset management system to a social network for product discovery and recommendation Seth graduated from Plymouth State College (now University) in Plymouth, New Hampshire, where he studied computer science and mathematics He is currently pursuing his M.S in Computer Science from the Georgia Institute of Technology Seth's blog can be found at http://blog.shrichards.com, and he can be followed on Twitter at @shrichards CuuDuongThanCong.com https://fb.com/tailieudientucntt ABOUT THE TECHNICAL EDITORS KEITH PEPIN has been developing sites and applications on the web for over 17 years Early in his career, he fell in love with JavaScript and has been passionately building dynamic user experiences ever since He is currently a Senior Software Engineer at Meltwater, and is using HTML5, CSS3, JavaScript, AngularJS, Node.js, and MongoDB to build the next generation of their online marketing intelligence platform When not coding or spending time with his family, he enjoys other geeky pursuits, including all forms of games, comic books, painting, and sketching JOHN PELOQUIN is a software engineer with over 10 years of JavaScript experience ranging across applications of all sizes John earned his B.A in Mathematics from U.C Berkeley and is currently a lead engineer at Spreemo, a healthcare technology startup in NYC Prior to editing this volume, John edited Professional Website Performance by Peter Smith (Wiley 2012) and Professional JavaScript for Web Developers, 3rd ed by Nicholas Zakas (Wiley 2012) When he is not coding or collecting errata, John can occasionally be found doing stand-up comedy at an open mic CuuDuongThanCong.com https://fb.com/tailieudientucntt ACKNOWLEDGMENTS Thank you to my wife, Bethany, for her love and support while we wrote this book, and for enduring (or enjoying?) many husband-less nights and weekends while I worked to meet a deadline –SETH RICHARDS Thanks to my family for encouraging me to pursue my dreams My dreams may include writing a book, but they begin and end with you –LARRY SPENCER This book would not have been possible without the willingness of others to share their knowledge and expertise with us and the community at large in book, blog, and source-code format Together, we'd like to acknowledge and thank: Douglas Crockford, for his exposure of good parts of JavaScript and his work on jsLint Nicolas Zakas, for the numerous books and blog posts he wrote that acted as guides through JavaScript's sometimes-treacherous waters, and also his maintenance of and contributions to ESLint Stoyan Stefanov, for his instruction on applying pattern-based development to JavaScript Robert C Martin, for instilling in us the desire to write clean code Fredrik Appelberg, for his creation of, and Dave Clayton for his contributions to, the AOP.js aspect-oriented programming framework Mike Bostock, for inspiring us with the D3 library for SVG graphics The folks at Pivotal Labs, for the creation of the open-source JavaScript framework Jasmine, and members of the community that have contributed to the framework The AngularJS team, for showing the world a great way to build singlepage applications The vast and growing network of generous people on sites such as Stack Overflow and GitHub Without you, we'd still be thumbing through manuals We would also like to express our appreciation to our project editor, Chris CuuDuongThanCong.com https://fb.com/tailieudientucntt Haviland, who deftly maneuvered us through the writing process from beginning to end Our copy editor, Nancy Rapoport, has read our book more carefully, and more times, than anyone else ever will For her dedication and suggestions we offer heartfelt thanks We would also like to express our sincerest thanks to our technical editors, Keith Pepin and John Peloquin Their JavaScript prowess helped us avoid more than a few technical errors Should any errors still exist, it's likely because we didn't follow some of their advice Our hats are off to you, gentlemen Finally, we'd like to thank Carol Long, the Executive Acquisitions Editor at Wiley, who gave us the opportunity to write this book Without her, we'd still just be a couple of guys that write software for a living We're still that, but now we're authors, too Carol announced her retirement from the publishing industry just before we finished the book We sure hope we weren't the straw that broke the camel's back! Thank you, Carol, and we wish you nothing but sunny days and margaritas in your retirement –LARRY AND SETH CuuDuongThanCong.com https://fb.com/tailieudientucntt JSLint L libraries, contracts line function x-accessor and line.x function line.y function linting tools Liskov, Barbara Liskov Subsitution Principle (SOLID) literals object literals Singleton Pattern and loops for forEach LRU (least recently used) cache M Mediator Pattern colleagues developing interfaces testing contracts fakeMediator game interface segregation CuuDuongThanCong.com https://fb.com/tailieudientucntt mediators developing testing testing Memoization Pattern AOP and testing unit tests method borrowing borrow( ) method functions qualifying borrower objects aspect suitability validator side effects donor objects testing methods See also chainable methods; functions asJSON( ) assert attaching to functions attachReturnValidator borrow( ) createATestObject fulfills iterate CuuDuongThanCong.com https://fb.com/tailieudientucntt multipleFulfills then mixins addID creating functional traditional functional TDD testing traditional mixins creating module pattern DRY and module creation immediate execution reliable at will SOLID and modules AOP versus scripts Singleton Pattern and monkey-patching See also method borrowing multipleFulfills method N namespaces CuuDuongThanCong.com https://fb.com/tailieudientucntt nested functions scope and new keyword binding and this new object creation pattern null data type data type number O objects construction, testing creating as dictionary as functions literals versus arguments method borrowing and new object creation pattern primitives properties, adding/removing prototype chains default inheritance wrappers Observer Pattern addObserver function components CuuDuongThanCong.com https://fb.com/tailieudientucntt recentRegistrationsService module testing opeators, instance of Open/Closed Principle (SOLID) optimization, profilers and inefficiency detection premature P parameters args type free partial function applications AOP (aspect-oriented programming) versus currying testing unit testing patterns Callback case study chess analogy Decorator Factory Mediator Memoization module creating modules immediate execution CuuDuongThanCong.com https://fb.com/tailieudientucntt reliable modules object creation Observer Promise Proxy Pattern Sandbox Singleton Strategy Pattern TDD and AOP apply function architectural divisions call function callbacks chainable methods conformance Decorator DOM access Factory Mediator Memoization method borrowing mixins object construction Observer partial function applications promise-based code CuuDuongThanCong.com https://fb.com/tailieudientucntt Proxy Sandbox Singleton Strategy vocabulary and plugins, AopJS polyfills prefetch function primitives DRY and SOLID and Promise Pattern chaining creating done( ) function fates HTTP requests versus jQuery promises returning states then method unit testing wrappers promise-based code, testing properties adding/removing functions, constructor functions CuuDuongThanCong.com https://fb.com/tailieudientucntt prototypes chains shared proxies Proxy Pattern testing Q-R QUnit testing framework refactoring register function returnValueCache S Sandbox Pattern testing unit testing function creation tools widget sandbox WidgetSandbox constructor instantiating tools scope nested functions and variables scripts versus modules segment function setID( ) function CuuDuongThanCong.com https://fb.com/tailieudientucntt side effects of method borrowing Single Responsibility Principle (SOLID) single-threading Singleton Pattern shared cache implementation modules and object literals and testing unit testing small-scale versus large-scale development software engineering DRY principle SOLID SOLID classical inheritance emulation Dependency Inversion functional inheritance Interface Segregation Liskov Subsitution modules monkey patching new object creation object literals and Open/Closed primitives and Single Responsibility specification See also testing CuuDuongThanCong.com https://fb.com/tailieudientucntt runnable squash analogy states, Promise Strategy Pattern testing transportScheduler implementation Strict Mode data type string strings SVG line code generation synchronous callbacks system testing T TDD (test-driven development) ad hoc code benefits development cycle extend function incorrect code identification mixins patterns AOP apply function architectural divisions call function callbacks chainable methods CuuDuongThanCong.com https://fb.com/tailieudientucntt conformance Decorator DOM access Factory Mediator Memoization method borrowing mixins object construction Observer partial function applications promise-based code Proxy Sandbox Singleton Strategy UI components unit-testable code, writing testing See also specification; TDD apply and bind call and callback functions designing for doubles ease of framework D.O.H CuuDuongThanCong.com https://fb.com/tailieudientucntt D.O.H Jasmine QUnit incorrect code identification maintenance and runnable system testing unit testing chainable methods Decorator Pattern Factory Pattern Memoization Pattern partial function applications Promise Proxy Pattern Sandbox Pattern Singleton Pattern Strategy pattern XMLHTTPRequest then method this bind and binding callbacks chainable methods and toThrow( ) function traditional mixins creating CuuDuongThanCong.com https://fb.com/tailieudientucntt type-free semantics U UI (user interface), unit testing component creation difficult-to-test code Jasmine test framework undefined data type unit testing Callback Pattern chainable methods Decorator Pattern do-nothing decorators error pass through fakes features generalization pass-through functionality pass-through successes Factory Pattern framework, Jasmine Memoization Pattern partial function applications Promise Proxy Pattern Sandbox Pattern function creation tools CuuDuongThanCong.com https://fb.com/tailieudientucntt widget sandbox Singleton Pattern Strategy Pattern, transportScheduler UI component creation difficult-to-test code V validateWithContractNameString valIncrementor function function variables declarations function scope this vocabulary, patterns and W WETness (Write Everything Twice or We Enjoy Typing) wrappers Promise X-Y-Z x-accessor, line and XMLHttpRequest testing YUI Do class CuuDuongThanCong.com https://fb.com/tailieudientucntt WILEY END USER LICENSE AGREEMENT Go to www.wiley.com/go/eula to access Wiley’s ebook EULA CuuDuongThanCong.com https://fb.com/tailieudientucntt ... Indianapolis, Indiana Published simultaneously in Canada ISBN: 97 8-1 -1 1 9-0 287 2-7 ISBN: 97 8-1 -1 1 9-0 287 3-4 (ebk) ISBN: 97 8-1 -1 1 9-0 287 4-1 (ebk) Manufactured in the United States of America No part of... United States at (877) 76 2-2 974, outside the United States at (317) 57 2-3 993 or fax (317) 57 2-4 002 Wiley publishes in a variety of print and electronic formats and by print-on-demand Some material... a mature, staid, starched-shirt-wearing programming language She is young, daring, and free-spirited She doesn't have the same long track record of success for large-scale software projects that