Web designers and developers nowadays are familiar with the critical decision they face each time before building an application intended for mobile devices: whether to target a particular device operating system (e.g., iOS) and create the app using the language dictated by the OS (e.g., Objective-C), or try to build an operating system-agnostic app that runs on any device equipped with a modern web browser (primarily using HTML5, CSS3, and JavaScript), or try to do a combination of both (using a library such as PhoneGap). The second option offers many advantages, and is the approach explored in the book Mobile HTML5, authored by Estelle Weyl, an experienced front-end developer.

This title was published on 14 November 2013 under the ISBN 978-1449311414, by O'Reilly Media (who graciously provided me with a review copy). The book's material, spanning 480 pages, is grouped into 14 chapters and an appendix, as well as an introduction in which the author presents the advantages of web apps versus native apps, a brief history of both categories (focusing on iPhone development), and an even briefer overview of the HTML5 APIs that are covered in depth in the chapters that follow. Prospective readers may want to first check the publisher's website, where they will find the table of contents, book details, author biography, and a list of errata (only eight as of this writing). In addition, the example code used in the book is available on the author's site. Oddly, the introduction does not specify the requisite knowledge that readers should possess to get the most out of the book. However, a solid understanding of HTML, CSS, and JavaScript would be most helpful; but prior exposure to HTML5 and CSS3 is unneeded, as is any knowledge of any JavaScript libraries, because the author intentionally eschews them in her presentation.

The first chapter, titled "Setting the Stage to Learn Mobile HTML5, CSS3, and JavaScript APIs," continues the discussion begun in the Introduction — largely focusing on the development and testing tools used throughout the book and needed by the reader if he desires to replicate the work described in the narrative. The author's sharp words against IE 6 will be especially appreciated by those designers and developers who have lost countless hours — from both their work schedules and possibly their lifespans — as a result of the rage-inducing layout quirks and other flaws of that demonic browser. Some readers may be confused by the author's instructions for accessing the developer tools in Google Chrome (View > Developer > Developer Tools); with the traditional menu bar now gone, the steps would be the menu icon > Tools > Developer tools.

The next two chapters provide fast-paced coverage of the HTML5 syntax and the new elements and attributes introduced in this latest version of the standard. There are only a few minor blemishes: The author sometimes backtracks, repeating information noted earlier, but worded somewhat differently. For instance, in the second chapter, readers are presented with the syntax of an HTML element (page 25), which is repeated ten pages later. More noticeably, the reader is told six times that the "title" element is required. In the next chapter, the discussion of the "details" and "summary" elements is quite repetitive. Incidentally, on page 76, the author mentions that the "iframe" element has a new attribute, "srcdoc," whose values should not include double quotes, which should be escaped with the """ entity; more accurately, they should be replaced entirely with that entity. Lastly, the explanation of the "sandbox" attribute values is inadequate; readers will need to consult other sources to understand the full meaning of those allowed values. Nevertheless, HTML authors of all levels of experience should be able to benefit from these two chapters.

Forms are an essential component of any dynamic website, and are covered in great detail in the fourth chapter, which explicates the many new features introduced in HTML5, such as validation and error messaging, which significantly reduce the prior reliance upon JavaScript for such functionality. The author does a fine job of explaining these promising new improvements to form elements. The only weakness is, again, redundant explanations — for instance, in the first three sections: "Attributes of <input>," "<input> Types and Attributes," and "New Values for <input> Type." A glaring example is found on page 96, where the second reader tip is echoed in the paragraph that follows it. Screenshots are provided showing the specialized keyboards displayed on the leading handheld devices for the email, URL, phone, number, search, and datetime input types. The chapter concludes with a discussion of form field validation (including use of the validity state object) and the remaining form-related elements, both new and old.

The next two chapters focus on the APIs introduced with HTML5 that were relatively well-defined at the time the book was written, beginning with those that implement SVG, canvas, audio, and video functionality within a webpage, and concluding with application cache, local storage, SQL database storage, geolocation, Web workers, microdata, and ARIA. Most of the narrative should be clear to the reader, although one problem is that sometimes the example code does not reflect the recommendations in the text. For instance, on page 136, the author notes that SVG image accessibility can be enhanced by using the "aria-label" attribute, and that the height and width need not be specified in the "embed" and "object" elements — and yet the code presented does not adhere to these guidelines. Also, on page 175, the author refers to forking code, but the code in question is not forked to a different project or revision; rather, she means different code is executed depending upon the chosen HTML5 database.

Chapters 7 through 10 focus on CSS3, including its unique selectors, color values, units of measurement, box model properties, gradients, shadows, transitions, and animations. It all begins with a review of CSS basics, including media queries and best practices — which makes this book even more viable as a single source for learning HTML and CSS coding. Media queries are touched upon only briefly, because they are covered in depth in a later chapter. Readers will likely find interesting the discussion of maximizing website performance by balancing the number of HTTP requests, the use of embedded styles, and the use of local storage of previously-downloaded CSS and JavaScript files. Oddly, there is inconsistency in the formatting of the example CSS code — for instance, three different formats on a single page (205). Nonetheless, the explanations are for the most part quite clear, aside from the "p:first-of-type" (on page 215). The many snippets of example markup and CSS clearly illustrate how cascading works, and how one can avoid overuse of IDs (and any use of !"important"). The coverage of pseudo-classes and pseudo-elements is quite thorough, with plenty of examples.

The last four chapters employ many of the topics covered earlier and apply them to responsive web design (RWD). Chapter 11 demonstrates how to use CSS 2 and CSS3 capabilities for building websites and web apps that can work and appear as best as possible on device viewports of any size — including those that have yet to be implemented. The information is valuable, marred only by a lack of CSS code showing how the examples were created (e.g., on page 343), prior to discussing the allowed property names and values, and their shorthand notation. Readers learn how to utilize multiple columns, border images, flexbox, @supports, and responsive images. That last topic is arguably the most unresolved aspect of RWD images, and perhaps that is the reason why the author does not discuss the emerging "srcset" attribute and "picture" element for handling the challenge of serving images whose file sizes are optimal for the device's viewport and connection speed. The last three chapters discuss various design and performance considerations one should bear in mind when developing for mobile devices. Most of the initial narrative is at a high level, while the later chapters get into the details of screen sizes, hardware, testing, battery life, and latency. Incidentally, the "meta" element on page 386 was probably not intended to be struck out. The book concludes with an appendix devoted to CSS selectors and specificity.

As with most technical books of this length, this one contains numerous errata: "on ithe Phone" (page xiii), "Chapters Chapter" (xxii), "a[n] OOCSS" (xxv), "that [the] Sources" (12), "never[-]used" (42), "developers that" (44; should read "developers who"), "spammers last millennium" (47; we wish!), "When [the] favicon" (51), "favico.ico" (ditto), "at [the] site" (ditto), "so [it] has" (66), "on [the] same" (77), "<detail>" (80; should read "<details>"), "Barn[e]s" (80), "])){" (95; should read "]){"), "seperate" (101), "override [the] default appearance" (102), "rangUnderflow" (121), "form control[']s value" (121), "requiredlist" (124, 125), "an list" (124), "pros of cons" (146), "first from" (149; should read "first frame"), "when [the] game" (168), "function [is] initially" (169), and "via [a] banner" (179). At this point, roughly halfway through the book, I stopped recording errata.

Most of the writing is clear and straightforward. However, some of the phrasing is a bit confusing, e.g., "is in the last call" (page 101). Other phrasing may come across as too flippant, e.g., "Duh!" (page 48). Some terms are used much earlier than when explained, e.g., "shadow DOM" (page 100). A few terms are used that can have various meanings depending upon the context, but in this book their intended meanings are not defined and likely would not be obvious to the average reader. For example, in Chapter 3, several times the author refers to the "outline" of a (presumably HTML) document and a "node" that one might create, but does not explain what is meant by those terms in these cases.

Most books that use some sort of example project to illustrate the ideas being presented, will weave it into the narrative when appropriate and/or as much as possible. The example project for this book, CubeeDoo, is mentioned countless times, but apparently not explained in its entirety, nor is discussed the stitching together of the code snippets into a complete application. As a consequence, the example project adds less instructional value to the book than could be expected given the amount of space devoted to it. Arguably, it would have been better to either make full use of the project as a teaching resource, or use a simpler application if the first option would have been overwhelming, or simply exclude it altogether from the text and, optionally, post it online for readers who wish to examine the code on their own.

In terms of the layout and presentation of the text, this book, like so many other O'Reilly Media titles, oftentimes has too little space between adjacent words, making it more difficult to read the text at a rapid pace and to quickly locate individual words known to be present on any given page (such as words found in the index). In some cases, attribute names are chopped off midway and continued on the next line, but without the standard hyphen to indicate word continuation (e.g., "ac / cesskey" on page 30). The same is occasionally done for JavaScript method names (e.g., "se / tAttribute" on page 39). Admittedly, for keywords such as element names and attributes, as well as JavaScript names, adding any hyphen might be even more misleading, as some readers might erroneously conclude that the hyphen is part of the name when not broken over two lines.

The book's primary problem is the repetition of information, not just within each chapter, but oftentimes even on the same page. This is true not only within the main text, but also in the reader tips, which sometimes present new and useful information, but far too often repeat the information found in the paragraph preceding the tip — sometimes an almost-verbatim repeat of the paragraph's last sentence. This is not of great consequence, and may be helpful to readers who miss an important point the first time it is presented. Some of it may be unavoidable, given the overlap among the various topics. But it certainly does add to the (nontrivial) length of the book.

Regardless, these are not overly important flaws. Suffused with the author's honest writing style — as well as her obvious experience and enthusiasm — Mobile HTML5 is a substantial and instructive treatment of the primary new techniques for building mobile-ready websites and web apps.

Michael Ross is a freelance web developer and writer.

An online store is one of the most common use cases for a website nowadays. For those web developers and business owners who choose the current version of Drupal as a basis for such an e-commerce project, the canonical solution is Drupal Commerce. There are numerous online resources for learning Commerce, and yet for the longest time no printed book. Now we have Getting Started with Drupal Commerce, written by Richard Jones.

This title was released by Packt Publishing on 24 September 2013, under the ISBN 978-1783280230. (This review is based upon a copy of the book kindly provided by the publisher.) On the book's website, visitors can read information about the book, including its table of contents, errata (none listed, as of this writing), and a sample chapter (the third one, on "Planning Your Store").

At first glance, 152 pages may seem wholly inadequate for explaining how to build an online store using Drupal Commerce. However, the table of contents suggests that, within the book's 10 chapters, the author addresses most of the critical topics: installation of the Commerce project, product catalog and classification, product data, shopping cart functionality, the checkout process, shipping services, taxes, order management, discounts, and coupons. A bonus chapter, "Extending Commerce," is not included in the book itself, but is available as a free download. (Readers should note that the URL provided in the book is incorrect, as it is missing the last underscore.)

Prospective readers do not need to know how to program in PHP or Drupal; however, a working knowledge of Drupal site building through the user interface, would be helpful. Anyone who wishes to follow the steps performed in the book for creating the example Commerce site, must have access to a Drupal 7 installation, with sufficient privileges to install and configure modules and set permissions, as needed.

The first chapter, "Introducing Key Concepts," as the title suggests, introduces the reader to the Drupal Commerce package, its overall capabilities, its submodules, and its dependencies. The module list (on page 6) is missing nine entries. Other than that, the material provides a good sense of what is to come. The first chapter, like all the others in the book, concludes with a brief and utterly useless summary. In this case, it states that the readers now "understand the motivation of the developers," even though that was not discussed in the chapter.

Installing Drupal Commerce is the subject of the next chapter. MySQL is listed as a requisite download, but actually MariaDB, PostgreSQL, and SQLite are equally usable. The author mentions Mac OS X and Windows as possible environments, but neglects Linux. Most of the chapter assumes that the reader has elected to use the Acquia Dev Desktop, and it consequently may prove frustrating to anyone who uses a different distribution to get started, or who installs the needed components individually.

As an e-commerce website is developed and (usually) later modified, the participants discover the value in all of the time and effort invested upfront in planning the information needed to track products, customers, payments, and other facets of the operation. Thus the third chapter is arguably one of the most valuable in the book, and should prompt site designers and developers to ask plenty of questions of their clients.

With Chapter 4, "Products," the author begins describing and illustrating the creation of the example website — in this case, a wholesale coffee and tea store based in the UK. At a critical juncture (page 35), the reader is instructed to enable "Commerce Backoffice (Commerce package)" and "Commerce Backoffice (Product package)," which is odd, since all four Commerce Backoffice submodules are in the "Commerce (contrib)" package, and none have those two exact names. Readers may presume that Commerce Backoffice and Commerce Backoffice Product were intended. It later turns out that "Commerce Backoffice content" was also needed. It is possible that the author was using an earlier version of Commerce that had different names, but that's difficult to ascertain because he apparently does not mention which version of Commerce is used in the book.

Chapters 5 and 6 demonstrate how to set up a shopping cart and configure the checkout process. The material should be comprehensible to the typical reader, and possibly a pleasant relief if his head is still spinning from the terminology soup encountered in the fourth chapter. The author explains how to use PayPal for accepting customer payments, and what permissions to set so that visitors to one's store can check out. Strangely enough, there is no discussion as to what permissions, if any, visitors will need for viewing products and adding them to the shopping cart. This might seem obvious to those experienced with Drupal Commerce, but likely will not be to neophytes.

The next two chapters show how to set up flat rate shipping as an option for one's customers, and how to apply a value added tax to each order, including the use of the Rules module for handling special cases flexibly, such as offering free or discounted shipping when the checkout balance exceeds a certain amount on any order not being shipped internationally. Lastly, readers learn how to set up order tracking.

The last three chapters demonstrate how to apply various tax rates to customer orders, how to manage orders on the back-end (such as setting status codes and viewing payment transactions), and how to define discounts and coupons that can be offered to prospective customers. The 11th chapter, on extending Drupal Commerce, should have been included in the published volume itself, as it certainly would not have pushed the page count beyond a reasonable level.

Throughout the book, almost all of the explanations are clear and straightforward, with the only exceptions being the puzzling reference to a "uid property" (page 10), which is not explained, and the use of several different phrases to describe product display nodes (in the fourth chapter). Unfortunately, all of the material apparently assumes that the reader will encounter no problems in trying to perform the same steps, because no troubleshooting resources are mentioned.

Aside from the aforementioned faulty URL on page 2, this book contains too many errata relative to its size: "out of the box" (page 5; missing three hyphens), "Apache based" (page 13; same problem), a space in the URL (page 15), "than [a] necessity" (16), "to [the] recently" (17), "Specifying [the] language" (25), "to [the] public" (27), "other than helper modules" (35), "Images/" (39; should be lowercase), "fairtrade" and "fair trade" (46 etc.; should read "fair-trade"), "doesn't" (47; should read "isn't"), "top-" (64), "blocks" (67; should read "block"), "rules" (73; should read "rule"), "as [a] page" (76), "as screen" (93), "field_tax_code" (106-107; should read "field_vat_code"), and "cine" (108; movies and Jamaican coffee have the same pricing?).

Like so many other books in the computer field, this one contains other flaws in the writing, such as semicolons used where commas are called for (e.g., page 5), and the mixing of singular and plural terms (e.g., page 28). However, its quality of writing is better than that of the majority of Packt Publishing's offerings.

Most of this book's screenshots are quite helpful, although a few might cause some confusion, mostly in that they do not reflect what the reader will see in her own installation. Consider only a handful of examples: An image field "Progress indicator" is mentioned (page 39), but not evident in any screenshot nor on the "Product image" edit page in my own installation. The screenshot on page 45 does not include the "Description" field that the reader is instructed to create, two pages earlier. A "Product: Tax code" field is shown (page 57), prior to any tax functionality being implemented in the narrative. The checkout web page is missing a field for an e-mail address (page 80). Alert readers will immediately wonder where in Drupal Commerce they would go to modify the billing fields, but that doesn't seem to be covered (but I could be mistaken).

One may level the charge that this book provides only the information needed to create a fairly simple e-commerce website. But that would be missing the point, because this book is not intended as an exhaustive exposition of the subject. Getting Started with Drupal Commerce is a valuable starting point for anyone interested in learning how to build online stores using Drupal 7.

Michael Ross is a freelance web developer and writer.

statement is missing the "<?" and two of the lines have mismatched single and double quotes.

The remaining half dozen chapters cover critical aspects of PHP development. The chapter on security does not attempt to be exhaustive, but instead explains the most common attack vectors and how to block them. The chapter on application techniques discusses code libraries, templating, output buffering and compression, error handling, and performance tuning. Any programmer intrigued by the idea of replacing clunky VBA code with PHP, should be interested in Chapter 14, which explores the differences in running PHP on Windows vs. other platforms, with a brief look at manipulating the contents of Microsoft Word and Excel files using PHP. RESTful web services and XML-RPC are the topics of the next chapter, whose only apparent blemish is that json_encode() does not add spaces between the array values (page 339). The penultimate chapter addresses multiple environments, manual debugging, and the use of an IDE. The last chapter briefly covers PHP support for dates and times, and thus should have been located much earlier in the book, with the other material on fundamental concepts.

Overall, this book is quite approachable. Throughout, one will find programming style recommendations, However, as with any technical work of this size, there are passages that could be made more complete or clear. Occasionally the authors will mention something explained only later — e.g., "short echo tag" (page 60) — which can be frustrating to anyone new to a language.

The concepts of PHP being taught are extensively illustrated with example code. Some of it is concise enough so as not to distract from the narrative flow, but far too many examples involve much more code than necessary. This at first glance might seem to be an advantage, but it actually makes it more difficult for the reader to see the parts of the code relevant to the topic at hand. Also, the authors underutilize whitespace in the code, instead jamming tokens and parentheses together.

In a book of this size, we should not be astonished to find some errata: "Wordpress" (page xv), "try and" (same page; should read "try to"), "tick function registered when register_tick_function()" (55; should read "with" not "when"), "eXtensible" (59), "super-global" (67; should read "superglobal"), "display_classes() function" (vs. "function displayClasses()"; 164), "$var" (294 and 295; should read "$value"), "functions of blocks" (323; should read "functions or blocks"), "retried" (337; should read "retrieved"), and "a.k.a." (350; should read "e.g.").

In terms of the production of the book, like most other O'Reilly titles, this one is nicely put together, with readable font. But sometimes words are jammed together so much that lines appear to be a single word, e.g., "codeitselfbutplentifulenoughthatyoucanusethecommentstotellwhat'shappening" (page 17). Also, the publisher should avoid splitting the function names as if they were English words, e.g., "addc" and "slashes()" on separate lines (page 91). The index is missing some obvious entries, e.g., "closures." Many code snippets are missing the "Example" numbers and captions. This may be fine if the authors do not reference those snippets, but makes it problematic for anyone else to reference them.

Even though this is arguably one of the most comprehensive PHP books on the market, it does not cover all aspects of the language. On page 1, readers learn that PHP can be utilized in three major ways — server-side scripting, command-line scripting, and client-side GUI applications; but only the first is covered in the book. The appendix consumes over 120 pages, and comprises information easily available online in the PHP manual's function reference. Those pages could instead have been devoted to at least introducing command-line scripting and GUI applications. In fact, there are two major changes the authors could take in bringing this book much closer to perfection: Firstly, retest all of the code and root out any technical snafus. Secondly, replace the lengthy appendix with full coverage of the topics of command-line scripting and client-side GUI applications.

Regardless, Programming PHP is both a tutorial and a reference resource packed with information and example code. Benefiting from the author's deep expertise in the language and its usage, the book is the most promising single source for anyone who wishes to learn this ubiquitous web scripting language.

Michael Ross is a freelance web developer and writer.