Domain: jquery.com
Stories and comments across the archive that link to jquery.com.
Stories · 8
-
jQuery 3.0 Stops Supporting Internet Explorer Workarounds (softpedia.com)
An anonymous reader writes: Thursday's release of jQuery 3.0 is "the first version that features absolutely no workarounds for old Internet Explorer browsers," reports Softpedia. "If customers are still asking you to work with IE6, IE7, and IE8, then you should stick with jQuery 1.0 for the foreseeable future." The jQuery blog explains that over 18 months of development, "We set out to create a slimmer, faster version of jQuery (with backwards compatibility in mind)... It is a continuation of the 2.x branch, but with a few breaking changes that we felt were long overdue." Besides jQuery's free, open source JavaScript library, they also released a "slim" version that excludes ajax and effects modules (as well as deprecated code), and a new version of the jQuery Migrate plugin. -
JavaScript Devs: Is It Still Worth Learning jQuery?
Nerval's Lobster writes: If you're learning JavaScript and Web development, you might be wondering whether to learn jQuery. After nearly a decade of existence, jQuery has grown into a fundamental part of JavaScript coding in Web development. But now we're at a point where many of the missing pieces (and additional features) jQuery filled in are present in browsers. So do you need to learn jQuery anymore? Some developers don't think so. The official jQuery blog, meanwhile, is pushing a separate jQuery version for modern browsers, in an attempt to keep people involved. And there are still a few key reasons to keep learning jQuery: Legacy code. If you're going to go to work at a company that already has JavaScript browser code, there's a strong possibility it has jQuery throughout its code. There's also a matter of preference: People still like jQuery and its elegance, and they're going to continue using it, even though they might not have to. -
Book Review: Creating Mobile Apps With JQuery Mobile
sagecreek writes "You can judge this book, at least in part, by the lengthy tagline on its cover: 'Learn to make practical, unique, real-world sites that span a variety of industries and technologies with the world's most popular mobile development library.' jQuery might not be your favorite framework on the long, long list of JavaScript possibilities. But Shane Gliser unabashedly describes himself as a jQuery 'fanboy...if it's officially jQuery, I love it.' Gliser is an experienced mobile developer and blogger who operates Roughly Brilliant Digital Studios. He also has some background in mobile UX (user experience), and both qualities show in this smoothly written, well-illustrated, 234-page how-to book that focuses on jQuery Mobile, a 'touch-optimized' web framework for smartphones and tablets." Read below for the rest of sagecreek's review. Creating Mobile Apps With JQuery Mobile author Shane Gliser pages 234 pages publisher Packt Publishing rating 9/10 reviewer sagecreek ISBN 9781782160069 summary Takes the reader from mobile prototyping and creating templates to mobile development and creating versatile mobile sites, with a project in each chapter. Don't be surprised when you extract the book's code examples and related items from a ZIP file that is almost 100MB in size. Gliser covers a lot of ground, and he covers it well in his 10 chapters. And each chapter contains a project.
The first thing you don't do in Chapter 1, "Prototyping jQuery Mobile," is work at a computer. In the true spirit of UX, Gliser briefly has you work with a pen and some 3x5 note cards. (Remember those?) Your initial goal is to roughly sketch out some designs for a jQuery Mobile website for a new pizzeria. But why the ancient technology? "We are more willing to simply throw out a drawing that took less than 30 seconds to create," Gliser writes. And: "Actually sketching by hand uses a different part of the brain and unlocks our creative centers." Furthermore, those on your team who are not coders can contribute comments, suggestions, and corrections to the emerging design.
In Chapter 2, "A Mom-and-Pop Mobile Website," you step over to your computer with Chapter 1's paper prototype in hand. You start converting the sketched design "into an actual jQuery Mobile (jQM) site that acts responsively and looks unique." You also begin building "a configurable server-side PHP template," and you work with custom fonts, page curl effects using CSS, and other aspects of creating and optimizing a mobile site.
"Mobile is a very unforgiving environment," Gliser cautions, "and some of the tips in this section will make more difference than any of the 'best coding practices.'" Indeed, he wants you to be aware of optimization "at the beginning. You are going to do some awesome work and I don't want you or your stakeholders to think it's any less awesome, or slow, or anything else because you didn't know the tricks to squeeze the most performance out of your systems. It's never too early to impress people with the performance of your creations."
Chapter 3, "Analytics, Long forms, and Front-end Validation," moves beyond "dynamically link[ing] directly into the native GPS systems of iOS and Android." Instead, Gliser introduces how to work with Google static maps, Google Analytics, long and multi-page forms, and jQuery Validate. As for static maps, he says, "Remember to always approach things from the user's perspective. It's not always about doing the coolest thing we can." Indeed, a static map may be all the user needs to decide whether to drive to a business, such as a pizzeria, or just call for delivery. And, as for Google Analytics: "Every website should have analytics. If not, it's difficult to say how many people are hitting your site, if we're getting people through our conversion funnels, or what pages are causing people to leave our site."
Meanwhile, desktop users are familiar with (and frequently irritated by) long forms and multi-page forms. Lengthy forms can be real deal-breakers for users trying to negotiate them on mobile devices. The author presents some ways to shorten long forms and break them "into several pages using jQuery Mobile." And he emphasizes the importance of using the jQuery Validate plug-in to add validation to any page that has a form, so the user can see quickly and clearly that an entry has a problem.
The focus in Chapter 4, "QR Codes, Geolocation, Google Maps API, and HTML5 Video," is on handling concepts that can be "applied to any business that has multiple physical locations." Gliser uses a local movie theater chain as his development example. It is "considering throwing its hat into the mobile ring," so a site is created that makes use of QR codes, geolocation, Google Maps, and linking to YouTube movie previews. Then, he shows how to use embedded video to keep users on the movie chain's site rather than sending them off to YouTube.
In Chapter 5, the goal is "to create an aggregating news site based off social media." So the emphasis shifts to "Client-side Templating, JSON APIs, and HTML5 Web Storage." Notes Gliser: "Honestly, from a purely pragmatic perspective, I believe that the template is the perfect place for code. The more flexible, the better. JSON holds the data and the templates are used to transform it. To draw a parallel, XML is the data format and XSL templates are used to transform. Nobody whines about logic in XSL; so I don't see why it should be a problem in JS templates."
Next, he shows how to patch into Twitter's JSON API to get "the very latest set of trending topics" and "whittle down the response to only the part we want...and pass that array into JsRender for...well...rendering" in a manner that will be "a lot cleaner to read and maintain" than looping through JSON and using string concatenation to make the output.
Other topics in Chapter 5 include programmatically changing pages in jQuery Mobile, understanding how jQuery Mobile handles generated pages and Document Object Model (DOM) weight management, and working with RSS feeds. Gliser points out that there is still "a lot more information out there being fed by RSS feeds than by JSON feeds." The chapter concludes with looks at how to use HTML5 web storage (it's simple, yet it can get "especially tricky on mobile browsers"), and how to leverage the Google Feed API. Explains Gliser: "The Google Feeds (sic) API can be fed several options, but at its core, it's a way to specify an RSS or ATOM feed and get back a JSON representation."
Chapter 6 jumps into "the music scene. We're going to take the jQuery Mobile interface and turn it into a media player, artist showcase, and information hub that can be saved to people's home screens," Gliser writes. He proceeds to show how "ridiculously simple it can be to bring audio into your jQuery Mobile pages." And he explains how to use HTML5 manifest "and a few other meta tags" to save an app to the home screen. Furthermore, he discusses how to test mobile sites using "Google Chrome (since its WebKit) or IE9 (for the Windows Phone)" as browsers that are shrunken down to mobile size. "Naturally, this does not substitute for real testing," he cautions. "Always check your creations on real devices. That being said, the shrunken browser approach will usually get you 97.5 percent of the way there. Well...HTML5 Audio throws that operating model right out the window."
Since "mobile phones are quickly becoming our photo albums," Gliser's Chapter 7, "Fully Responsive Photography," begins with creating a basic gallery using Photoswipe. Then, in a section focused on "supporting the full range of device sizes," he shows how to start using responsive web design (RWD), "the concept of making a single page work for every device size." The issues, of course, range from image sizes and resolutions to text sizes and character counts per line, on screens as small as smart phones and tablets, or larger.
In Chapter 8, "Integrating jQuery Mobile into Existing Sites," three topics are key: (1) "Detecting mobile — server-side, client-side, and the combination of the two"; (2) "Mobilizing full site pages — the hard way"; and (3) Mobilizing full site pages — the easy way." Gliser avoids some potential "geek war" controversies over "browser sniffing versus feature detection" when detecting mobile devices. He zeroes in first on detection using WURFL for "server-side database-driven browser sniffing." He also shows how to do JavaScript-based browser sniffing, which he concedes may be "the worst possible way to detect mobile but it does have its virtues," especially if your budget is small and you want to exclude older devices that can't handle some new JavaScript templating. He also describes JavaScript-based feature detection using Modernizer, plus some other feature-detection methods.
As for mobilizing full-site pages "the hard way," he states that there is really "only one good reason: to keep the content on the same page so that the user doesn't have one page for mobile and one page for desktop. When emails and tweets and such are flying around, the user generally doesn't care if they're sending out the mobile view or the desktop view and they shouldn't." He focuses on how "it's pretty easy to tell what parts of a site would translate to mobile" and how to add data attributes to existing tags "to mobilize them. When jQuery's libraries are not present on the page, these attributes will simply sit there and cause no harm. Then you can use one of our many detection techniques to decide when to throw the jQM libraries in."
Mobilizing full-size pages "the easy way" involves, in his view, "nothing easier and cleaner than just creating a standalone jQuery Mobile page...and simply import the page we want with AJAX. We can then pull out the parts we want and leave the rest." His code samples show how to do this.
Chapter 9, "Content Management Systems and jQM" looks at the pros and cons of using three different content management systems (CMS) with jQuery Mobile: WordPress, Drupal, and Adobe Experience Manager. "The key to get up and running quickly with any CMS is, realizing which plugins and themes to use," Gliser writes. "For WordPress, I would not recommend a jQuery Mobile plugin. As I was experimenting for this chapter, it broke the admin interface and was, in general, a miserable experience. However, there are several jQuery Mobile themes that will serve you well. Some are free, some paid." He explains how to use mobile theme switchers.
Meanwhile, Drupal offers some standard plugins that provide contact forms, CAPTCHA, and custom database tables and forms, and enable you to "create full blown web apps, not just brochureware sites." But: "The biggest downside to Drupal is that it has a bit of a learning curve if yo want to tap its true power, Also, without some tuning, it can be a little slow and can really bloat your page's code," he says.
As for Adobe Experience Manager (AEM), Gliser merely introduces it as a "premier corporate CMS" and a "major CMS player that comes with complete jQuery Mobile examples." He doesn't show "how to install, configure, or code for AEM. That's a subject for several training manuals the size of this book." He adds: "If you work for a company that can afford AEM, you'll already be well-versed in the mobile implementation. The power this platform gives to content authors is astounding."
Chapter 10, the final chapter, is titled "Putting It All Together — Flood.FM." Using what you've learned in the book, including paper prototyping the interfaces, you create "a website where listeners will be greeted with music from local, independent bands across several genres and geographic regions."
Along the way, Gliser introduces Balsamiq, "a very popular UX tool for rapid prototyping." He discusses using Model-View-Controller (MVC), Model-View-ViewModel (MVVM), and Model-View-Whatever (MV*) development structures with jQuery Mobile. He introduces how to work with the Web Audio API , and he illustrates how to prompt users to download the Flood.FM app to their home screens. He finishes up with brief discussions of accelerometers, cameras, "APIs on the horizon," plus "To app or not to app, that is the question" and whether you should compile an app or not. Finally, he shows PhoneGap Build, the "cloud-based build service for PhoneGap."
Shane Gliser's book does indeed cover a lot of ground, clearly and with good examples. If you truly demand that some nits must be picked, I can report that an occasional dash is missing or a comma sometimes shows up out of place, such as this example in Chapter 2: "A practice is only best until a new practice, [misplaced comma] comes along that is better." In the printed book's table of contents, there are style and spelling glitches in the heading for Chapter 3. "Analytics, long forms, and frontend validation" should be "Analytics, Long Forms, and Front-end Validation." And, in Chapter 5, Gliser refers to the "Google Feeds API" when it's actually "Google Feed API." But the term "Google Feeds API" commonly is misused by developers on Stack Overflow and other sites.
I am not a mobile developer. I am a tech writer, frequent book reviewer, and occasional coder. I have played with some of the code examples in this book, but I have not tried them all. So I can't say if there are code glitches. However, the book was reviewed before publication by at least four software professionals with impressive resumes.
Aside from occasional spots where the text needed tighter editing, this book is, in my view, well written and rich with information, examples, sources, and tips for working effectively with jQuery Mobile. I intend to put it to good use as I continue learning.
You can purchase Creating Mobile Apps with jQuery Mobile from amazon.com. Slashdot welcomes readers' book reviews (sci-fi included) -- to see your own review here, read the book review guidelines, then visit the submission page. -
jQuery 2.0 Will Drop Support For IE 6, 7, 8
benfrog writes "The developers of jQuery recently announced in a blog entry that jQuery 2.0 will drop support for legacy versions of Internet Explorer. The release will come in parallel with version 1.9, however, which will include support for older versions of IE. The versions will offer full API compatibility, but 2.0 will 'benefit from a faster implementation that doesn't have to rely on legacy compatibility hacks.'" -
jQuery Cookbook
Michael J. Ross writes "Like all major programming languages, JavaScript can be extended in functionality through the use of libraries, such as jQuery, which is currently seeing tremendous popularity and enhancement in the Web development community. Designers and developers who want to learn how to use jQuery for creating rich user interfaces through client-side JavaScript are advised to begin their journey to jQuery proficiency by reading one of the many books dedicated to this powerful JavaScript resource — such as jQuery Cookbook: Solutions & Examples for jQuery Developers." Read below for the rest of Michael's review. jQuery Cookbook author Various authors pages 480 pages publisher O'Reilly Media rating 9/10 reviewer Michael J. Ross ISBN 978-0596159771 summary An extensive collection of solutions to jQuery problems. This book was published by O'Reilly Media on 19 November 2009, under the ISBN 978-0596159771, and is authored by no fewer than 19 contributors — all quite knowledgeable of JavaScript and jQuery — and edited by one of those contributors, Cody Lindley. On the publisher's page for the book, visitors can read the book's description, table of contents, and errata, of which there are 22 as of this writing, although none have been confirmed by the authors or publisher. Visitors can also download all of the sample code used in the book, in addition to the eight code demos for Chapter 13. Lastly, prospective buyers can purchase the print version of the book, the electronic one (in PDF, ePub, and Mobi format), or the two combined at a considerable discount — or read the book as part of Safari Books Online.
jQuery Cookbook's 480 pages are organized into 18 chapters, covering a wide range of topics: the basics, element selection, utilities, dimensions, effects, events, forms, plug-ins, user interfaces, theming, Ajax, data formats, and testing. Lindley starts off the first chapter, titled "jQuery Basics," by presenting the advantages, philosophy, and organization of jQuery. Readers will likely chuckle at his suggestion that they memorize the jQuery API outline, which comprises two pages. The many code snippets are quite helpful, but they are needlessly long, partly because most of them contain far more HTML elements than are needed to illustrate the point, and also because each snippet contains the DOCTYPE and head tags, among others — often taking up more lines on the page than does the code pertinent to the topic at hand. This pointless and space-wasting redundancy is seen also in a few of the chapters that follow. As well, some of the passages in the first chapter's narrative are oddly phrased, frequently requiring a rereading of the material, while others could be made more concise. Additionally, some of the sample code contains bugs, which fortunately are detailed on the errata page mentioned earlier. The second chapter, "Selecting Elements with jQuery," presents numerous techniques for specifying elements within the DOM. The only obvious blemish in the material is in section 2.4, where the author refers to animated elements, but with absolutely no explanation as to what that means; countless new readers may assume he is referring to animated GIFs. Nonetheless, these two chapters form a helpful foundation for the rest of the manuscript.
The third chapter, "Beyond the Basics," gets off to a questionable start with the assertion that "jQuery can [] extend jQuery to infinite possibilities," which sounds like a line wisely rejected for the movie Toy Story. Yet the discussion continues on a solid footing, as it covers more advanced techniques for working with selected elements. Some of the discussion overlaps material presented in the previous two chapters, but it is always worthwhile to hear critical concepts explained from a different perspective. However, section 3.8, which briefly introduces jQuery plug-ins, is out of place; that material should be folded into Chapter 12, which focuses on that topic. The fourth chapter may be brief, but it explains several jQuery utility methods. Most of the code snippets use a format of "(function($) (jQuery);" — whose usage and advantages are not explained in this chapter, nor any earlier ones. This points up one of the key downsides of having almost every chapter of a programming book written by separate authors: readers can be confused or misled by disparities in coding practices, especially when the reasoning behind them is not given. The title of the fifth chapter, "Faster, Simpler, More Fun," is a bit misleading, because the authors don't explain how to make one's jQuery programming simpler or more fun, but they do provide a great deal of information on troubleshooting, performance optimization, and jQuery coding practices, including those pertaining to progressive enhancement, accessibility, and unobtrusiveness. Section 5.19 lacks a figure showing the menu being discussed, but that's the only obvious flaw.
The remaining chapters are dedicated to more specific aspects of jQuery programming, including the important topics of page layout as well as element positioning and sizing, discussed in Chapter 6. The subsequent chapter delves into effects, which is one of the more exciting topics in the jQuery realm. Even though a portion of the readers may be put off by the trickiness of the code, the material does demonstrate some of the powerful capabilities of jQuery effects — which in conjunction with HTML5 may easily encroach on areas of client-side programming formerly dominated by Adobe Flash. Throughout Chapter 7, most if not all places where the author refers to the "mouse," he apparently means the "mouse pointer." Events play a critical role in JavaScript software, and even more so for code that is mostly jQuery — thus the value of chapters 8 and 9, which examine basic and advanced event handling. The next pair of chapters discuss a variety of techniques for enhancing HTML forms, from scratch and through the use of jQuery plug-ins. The sample source code is better commented than what is seen elsewhere in the book, and the explanations are quite good. The subsequent chapter focuses on jQuery plug-ins, beyond their usage within HTML forms, and briefly explains how to create your own plug-ins and how to perform unit testing on them.
Because JavaScript is primarily a client-side technology, it should come as no surprise that jQuery can prove an outstanding tool in crafting user interfaces for Web sites and Web-based applications. Chapters 13 through 15 explore such topics as drop-down menus, sliding panels, rotating images, modal windows, tooltips, the jQuery UI, and how to style jQuery UI widgets, a.k.a., theming. No Web interface is an island, and over the years there have emerged a number of data formats and protocols for utilizing those formats for transmitting information between browsers and servers — such as Ajax, XML, JSON, and JSONP — covered in Chapter 16. Finally, the last two chapters of the book are geared more to testing and deployment, and less so to interface design and development. The topics covered include techniques for persisting data in the browser, managing large amounts of code and data for major software projects, automating the unit testing of jQuery code, testing callbacks and user actions, grouping and selecting tests, and more.
Overall, jQuery Cookbook starts off with some basics, and only then moves on to higher-level concepts and related use cases. However, the book is ostensibly aimed at beginners and intermediate JavaScript programmers, but the former group may find the ideas difficult to grasp fully, despite the introductory chapters — because some of the techniques are fairly advanced, they involve terminology unfamiliar to anyone new to jQuery, and some of that terminology is not explained. On the other hand, the recipes are generally well written and clear, supplemented with properly tested and working code. Consequently, anyone who takes the time to work through the examples patiently, should be well rewarded.
Because of its coverage of a wide range of topics, jQuery Cookbook can be used not only as a learning aid, but in some respects also as a reference — and in this regard the book's index will be quite useful. In light of the considerable length of the manuscript, reading it from stem to stern would involve an investment of time — especially if one were to work through all of the examples and try them out in one's own development environment — quite easily, in fact, since all of it can be downloaded from the publisher's site. Most of it, however, is organized as plain text files, and not HTML files; and no reason is provided for this annoying choice.
In terms of the layout and appearance of the text and figures, one flaw is that in countless lines throughout the book, the words are jammed together, making it difficult to read the text rapidly. In fact, some of these lines almost look like single words. This is also seen in the subheads, an excellent example of which can be found on page 149: "Solution2:ChangingthehrefAttributeoftheStylesheetThat'sResponsible." Unfortunately, the same is true for much of the source code, but in a different sense: Operators and variables are jammed together, clearly illustrating the need for whitespace in making code more readable. Some of the code is excessively long (noted earlier), and the authors are inconsistent as to whether their JavaScript is placed at the end of the body element or in the header element. Nonetheless, the sample code is generally of good quality.
There is another aspect related to not only this book but all other computer programming books for which individual chapters are written by different authors: jQuery Cookbook does not seem to be a single book, but instead a collection of books that were bundled together because of a common thread, namely, jQuery. This leads to some of the problems mentioned earlier, such as discrepancies in coding techniques and formatting — from which the beginning reader is supposedly learning best practices. On the other hand, the multi-author approach makes it possible for each major subject area to be handled by one or more writers who are expert in that particular area — which in turn results in a better product overall, even if one or two of the chapters are noticeably weaker than the others.
The book contains a number of copyediting flaws not listed on the aforementioned errata page: "elevated" should instead read "alleviated" (page 12); "or [its] alias" (13); "could change" should read "could be changed" (26); "jQuery('a')removeAttr('title')" is missing a "." (30); "'blue')" is missing a terminating ";" (50); "season in" should read "season" (56); "was contained" should read "is contained" (144); "position: absolute" in the narrative should not be broken between two lines (156); "great[er] than" (157); "equal[-]sized panels" (160); "only running" should read "only runs" (165); "still support[s]" (168), "#source5txt" should read "#source4txt" (217); and at this point I stopped recording errata. Also, in countless places in most of the chapters, semicolons are used where dashes are called for, and vice versa. O'Reilly's copyeditors should have detected and fixed those errors prior to publication.
Yet most of these blemishes are of little significance. What really counts is the overall value provided to the reader: Usable for both learning and reference, jQuery Cookbook delivers a tasty buffet of programming essentials, best practices, illustrative examples, optimization tips, and other information of value to JavaScript developers who wish to spice up their Web creations with jQuery.
Michael J. Ross is a freelance website developer and writer.
You can purchase jQuery Cookbook: Solutions & Examples for jQuery Developers from amazon.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page. -
Learning JQuery 1.3
Michael J. Ross writes "Of all Web technologies, JavaScript may have the most checkered past — first heralded as a powerful object-oriented language for jazzing up Web pages, but later condemned as a source of spammy pop-up windows and horrid animations polluting websites everywhere. Yet during the past several years, Web designers and developers are increasingly using JavaScript unobtrusively, for client-site interactivity — as a supplement to server-side functionality, not a replacement, and built upon standards-compliant (X)HTML and CSS. As a result, the once-derided language is now enjoying a true resurgence in interest and use. This has been bolstered by the proliferation of JavaScript libraries, of which jQuery is clearly the front runner. Web programmers seeking to get up to speed on this exciting resource can turn to Learning jQuery 1.3: Better Interaction Design and Web Development with Simple JavaScript Techniques." Keep reading for the rest of Michael's review. Learning jQuery 1.3 author Jonathan Chaffer, Karl Swedberg pages 444 pages publisher Packt Publishing rating 9/10 reviewer Michael J. Ross ISBN 978-1847196705 summary A detailed introduction to this popular JavaScript library. Written by Jonathan Chaffer and Karl Swedberg — two veteran Web developers based in Grand Rapids, Michigan — Learning jQuery 1.3 was published on 13 February 2009, under the ISBN 978-1847196705, by Packt Publishing, which kindly provided to me a copy of the book for review. There is a publisher's Web page for the book, where readers can order print or PDF versions of the book (or both, at a sizable discount); contact Packt Publishing with questions or feedback; read more information about the book, the authors, and the table of contents; and download a free sample chapter (the fourth one, titled "Effects") in PDF format. Readers who want to follow along with the authors' discussion, should note that all of the sample code used in the book can be downloaded from its support page. There is also a link for reading the reported errata, of which there are eleven, as of this writing. (The erratum for page 40 is incorrectly listed twice.)
The book begins with a foreword by John Resig, the creator of jQuery. What follows is over 400 pages of information, organized into eleven chapters and four appendices, covering all of the major topics related to jQuery, after a quick-start chapter: selectors, events, effects, DOM manipulation, AJAX, tables, forms, shufflers and rotators, plug-ins, online resources, development tools, and closures. The book has all the ingredients to serve as a full introduction to jQuery for experienced Web programmers, because it assumes no prior knowledge of jQuery (or any other JavaScript libraries); but it does assume that the reader comprehends the basics of HTML, CSS, and JavaScript — thus not wasting time by teaching these prerequisites skills, as is attempted in some other Web programming books.
The first chapter may be brief, but it is sufficient to present the major features of jQuery, its advantages versus raw JavaScript, and a quick history of its various releases after it was first mentioned by John Resig in August 2005. In addition, the reader is shown where to obtain the library, how to add it to a Web page, and a few of its basic capabilities. In the given example, multiple HTML paragraph elements are styled using just three lines of code; yet the power of jQuery would have been demonstrated even better had the authors also shown the equivalent raw JavaScript needed to perform the same functionality.
The next four chapters present the basics of jQuery upon which everything that follows is built. Readers are introduced, in Chapter 2, to the jQuery syntax for accessing individual elements and groups of elements on a Web page, using the $() factory function, CSS selectors, and jQuery's own custom selectors. As with all of the chapters that follow, several examples are used to illustrate the core ideas. The ability to intercept and react to events on a Web page — such as a user clicking on a particular link — is an essential part of client-side interactivity, and is the topic of the third chapter. But first the groundwork is set by learning how to control when code is executed, how to utilize multiple scripts on a page, and how to use jQuery with other JavaScript libraries. Then a style switcher example is used to demonstrate the "this" keyword, shorthand event methods, and compound events, as well as event capturing, bubbling, objects, targets, propagation, delegation, namespacing, and other topics. Unfortunately, the screenshots are of little help, largely because the black-and-white images fail to show user feedback, such as green backgrounds on hover, and even bolded link text. Chapter 4, which covers jQuery effects, begins by explaining how to programmatically discover and save attribute values, for later use; then it explains how to hide and show HTML elements, fade them in and out, toggle their settings, create simple custom animations, invoke effects sequentially using queuing, and queue effects on different elements using callback functions. The fifth chapter shows how to easily add and remove elements and their attributes from the DOM, and even create a new DOM structure from scratch. Most of the sample code is well explained, except for the fourth line in the insertAfter() snippet on page 96, which is not clear at all. Also, the sample text that consumes the bulk of pages 98 and 99, should be replaced with something much shorter, partly because it would be easier to locate the "span" tags within the text. This chapter, like the previous one, concludes with a "nutshell" summary that is quite helpful — and would be even more so if it listed, next to each jQuery method, the corresponding page number.
Asynchronous JavaScript and XML (AJAX) is a combination of technologies that is seeing more widespread use every year, as developers discover the advantages of dynamic Web page interactivity without the reloading of the page each time, which of course slows down the process for the user. The sixth chapter shows how to utilize AJAX, from a jQuery perspective, with explanations and examples of the four major approaches that involve static data files, including a handy summary of when each approach would be most appropriate. Also explored are the dynamic AJAX strategies, including GET and POST requests. The authors should have mentioned that, in order to make functional the "E" and "F" dictionary entries in the example, the reader will need to load the index.html file using a Web server, and not as a static HTML file, so the calls to "e.php" and "f.php" will work. By the way, anyone confused by the reference to jQuery Reference Guide, on page 146, should be aware that it is the title of a book written by the same authors as this one.
With the seventh chapter, the authors transition from what they consider to be the tutorial portion of the book, and begin to demonstrate how the reader can utilize the earlier basics for improving Web page functionality — in this case, working with tables. The authors make good use of code snippets and screenshots to show how one can do table sorting, row striping, row highlighting, and other capabilities independent of — and in conjunction with — server-side equivalents. The subsequent chapter consists of a similar survey of jQuery goodness, but applied to forms — specifically: styling, client-side validation, auto-completion of search entry fields, and input masking (with an emphasis upon numbers). The sample HTML is a model of quality markup, except for the wrapping of checkbox input elements inside of label elements, which is noncanonical and can make it problematic to properly align all the checkboxes in a form vertically, for all browsers. Chapter 9, titled "Shufflers and Rotators," demonstrates how to create a rotator for RSS newsfeed headlines, and an image carousel featuring image enlargement with transition. Readers interested in testing out the sample code — and possibly even modifying it — should be aware that, for chapters 7 through 9, the sample code within the downloadable archive is not stored in chapter-named directories, but instead combined into an application, in the "bookstore" directory.
The last two chapters of the book are devoted to jQuery plug-ins — using those created by others, and developing one's own. In Chapter 10, to illustrate the high-level ideas, the authors focus on and recommend a number of specific plug-ins built for handling forms, advanced effects, widgets, tables, images, and charts, as well as some theming resources. In the subsequent chapter, the authors show how to develop plug-ins of varying complexity, including those that implement new global functions, implement new jQuery object methods, and extend the jQuery selector engine; the chapter wraps up with advice on how best to distribute newly-created plug-ins.
All of the chapters end with summaries, which, given the detailed and technical nature of the material within each chapter, do not add any value to the book, and could be excised without loss. The four appendices offer some valuable information: numerous online resources for readers seeking reference material; development tools for the most popular Web browsers; details on JavaScript closures; and a quick reference for the jQuery selector expressions and all of the methods. The weakest part of the book, the index, is inadequate — missing important terms, such as "animation," "callback," "iteration" (or "iterator"), and "toggling."
The following errata have yet to be listed on the book's support page: "Let[']s" (page 23), "page [is] loaded" (page 40), "if Normal was" (should read "if Normal were"; page 61), ", though" (should read "though,"; page 80), "user the $() factory function" (page 113), "slices with be" (page 283), and "though[,] there" (page 340). In the errata listed on the support page, the entry for parseFloat refers to page 74, but the error actually occurs once on page 69 and twice on pages 70, 71, and 79. In the six screenshots on pages 253 through 257, the shipping totals are incorrect. Nevertheless, the number of errata per page is far less than what is found in most computer books, especially those from Packt Publishing.
The generous amount of sample code should be quite helpful to the reader, because for most programmers, we learn best by example. However, there are many instances where a line of code is unnecessarily wrapped to a second line, even though there is plenty of room at the end of the first line to accommodate the portion of code forced down; pages 82 and 217 have glaring examples of this. The same premature wrapping is seen in some of the text, such as on pages 210 and 311.
The authors as a whole do an admirable job of explaining the central ideas. The explanations are generally clear, which is absolutely critical for a topic like jQuery that can be overwhelming to anyone unfamiliar with it — and not just as a result of the somewhat cryptic syntax (which admittedly is unavoidable), made worse by chaining and especially by the nesting of anonymous functions. Even a cursory glance through the book should make evident that the authors put a lot of effort into writing it, reflected not just in its substantial length, but also the number of examples they created for the book, and the functionality contained therein.
With its thorough coverage of key jQuery topics — from the basics to plug-in development — Learning jQuery 1.3 is an information-packed resource that can help Web developers learn how to take their JavaScript programming to the next level.
Michael J. Ross is a freelance website developer and writer.
You can purchase Learning jQuery 1.3 from amazon.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page. -
Crowdsourcing JavaScript Testing
snitch writes "John Resig, creator of the jQuery JavaScript library, has released Test Swarm, a platform for distributed continuous integration testing for client-side JavaScript. Frustrated with traditional JavaScript testing environments that don't scale, John's new project, which is currently in private alpha, aims to provide a system for outsourcing browser-related testing to large groups of people or communities." -
Microsoft and Nokia Adopt OSS JQuery Framework
soliptic writes "The jQuery blog today announced that 'Both Microsoft and Nokia are taking the major step of adopting jQuery as part of their official application development platform.' So the open-source javascript framework will be shipped with Visual Studio and ASP.NET MVC. Microsoft's Scott Hanselman notes: 'It's Open Source, and we'll use it and ship it via its MIT license, unchanged. If there's changes we want, we'll submit a patch just like anyone else.'" There's also a story at eWeek about the decision.