Most computer and web programming books are written entirely by a single author, while the remaining are written by more authors, typically with each one tackling several chapters. The latter approach can suffer from redundant material undetected by editors, and inconsistency in the writing style from one chapter to the next. Yet it offers the significant advantage that the subject matter of each chapter can be presented by an authority on that topic — who can focus on making that explication the best possible, without the burden of completing an entire book. That was one of my first thoughts (and hopes) when hefting the 1112 pages and 4.1 pounds of the Definitive Guide to Drupal 7.
This tome was published on 19 July 2011, under the ISBN 978-1430231356, by Apress (who kindly provided a review copy). As of this writing, it appears to be the longest Drupal book in existence — more than 400 pages longer than the nearest two contenders. Fortunately, no single author ended up in an insane asylum as a consequence of trying to write such an extensive work on his own. Rather, this book is largely due to the efforts of 34 writers in total — more specifically, 30 authors (listed on the front cover, roughly in descending order of how many of the pages they wrote) and four more contributors (added to the list on the title page). This may be a new record in technical book publishing. The entire authorial crew won't be listed here, but it should be mentioned that Benjamin Melançon was the lead author, and contributed to many of the chapters.
The book's material is organized into 38 chapters and nine appendices — all grouped into eight parts: Getting Started, Site Building Foundations, Making Your Life Easier, Front-End Development, Back-End Development, Advanced Site-Building Topics, Drupal Community, and Appendix. The chapter and appendix titles won't be listed here, but can be found on the publisher's book page, which also offers a description of the book, a section for reported errata (none as of this writing), links to purchase the print and electronic versions of the book, and a downloadable archive of the source code. Unfortunately, the code is apparently available only as a Git repository, and thus is inaccessible if you cannot — or do not want to — install Git on your computer. Consequently, it would be more difficult for such a reader to follow along and implement the example code while reading the book.
The authors have created their own website for the book, where visitors can sign up for email notification of updates and free chapters, view a chapter outline (which features some bonus material), see author photos and bios, offer suggested changes for future editions, and learn of reported errata (three, at this time). Throughout the book, readers are told to access that site for additional information related to the chapters' topics; yet there does not appear to be any such information, even after registering a new account and logging in. This will be most disappointing in those cases where the reader is enticed by the promise of valuable information, only to find that it is absent. The authors state (page lv) that there are forums, one per chapter; but those do not yet exist. In general, there seems to be a huge disconnect between that website and the claims made in the book as to what extra material readers will find there.
The book begins with some introductory material, consisting of three mini-chapters: "What's New in Drupal 7" briefly describes some of the terrific improvements over version 6. "How to Use the Book" reassures the prospective reader that the book "does not presume any specific prior curriculum", although this seems inconsistent with the back cover's user level of "Intermediate-Advanced". Also, readers may be perplexed by the claim that the URL path admin/people/permissions/rules will go to admin/help (page lv). The last section, "How Drupal Works", oddly does not explain how Drupal works, but instead discusses some common terms and the typical phases of a website development project.
The first part of the book comprises two chapters, the first of which has the promising title of "Building a Drupal 7 Site", and provides a cursory summary of site planning, wireframing, Drupal installation, the Administration menu, the Shortcut toolbar, color schemes, and modules. The chapter continues with sections on content types, blocks, taxonomy, and other key concepts — all grouped under the chapter head "Allowing People to Register and Log in with OpenID", even though those topics are unrelated to OpenID. All of the chapter's topics are illustrated by stepping the reader through building, from scratch, the beginnings of the Drupal 7 website — namely, one similar to the authors' site mentioned earlier. Unfortunately, some of the instruction in the book does not match the actual website design, e.g., no introductory text (page 20). Readers may be amused by the tip on page 11, which refers to "the remaining 800 pages of the book". Perhaps the remaining 1101 pages can be chalked up to scope creep! The second chapter explains the basics of how to install and use Drush and Git, but not for Windows users. Readers should find the material instructive and consistent, except for the claim that Git is "easy(ish)" even though "getting the hang of Git [is] a lifelong learning process".
The half dozen chapters that compose Part II first introduce some of the most commonly-used Drupal modules, with extensive coverage of Views and later Organic Groups. A couple chapters explain how to keep one's site secure, partly by updating Drupal core and modules. The last chapter continues the development of the example site, using modules presented earlier. All of these chapters' narrative is valuable, although a couple pronouncements are too severe (e.g., "User input is evil", on page 127); but overall the advice is well warranted. Yet the chapter that will most likely aggravate readers is the eighth one. It seems to presume that the reader's test site was not affected by the exercises of the previous chapters, such as the Organic Groups. Secondly, some key information is incorrect, e.g., "Content: Image" (page 159) should be "Content: Headshot". Lastly, the authors refer to items not yet created as though they were, e.g., a "Table of Contents" menu link, an "Outline of Chapters" menu, and a "Twitter" field (pages 162-164). Unfortunately, the effects of all these problems compound, and, combined with the changes in Views since Drupal 7.0, make it increasingly difficult to follow along and implement the instructions.
Part III offers another half dozen chapters, in this case devoted to higher-level, less technical matters — specifically, how to: best participate in the Drupal community, plan and manage a Drupal-based project, craft effective documentation for your sites' end users and support staff, set up a workable Drupal development environment, launch and backup a new website, and stay sane while doing all of this. The information presented is worthwhile, with only a couple peculiarities: Firstly, why is the book organized so that some technical information is presented in the early chapters, as well as later chapters, while a group of "softer" topics are sandwiched in between? Secondly, for Chapter 12, why is the reader told, halfway through the chapter, that she will need "A computer able to connect to the Internet" and "An Internet connection" (page 233)? No one who has worked through the preceding dozen chapters needs to be reminded of this. Perhaps this chapter, on how to set up a development environment, should be made an appendix, as was the other installation and setup topics (Appendices F-I).
Part V, "Back-End Development", comprises seven chapters that explain how to develop custom Drupal modules using the APIs. Because they provide an introduction to Drupal's system of hooks and overrides, they probably should have been located before the earlier chapters on theming, which rely upon those features of Drupal. Regardless, Chapters 18-20, by Benjamin Melançon, attempt to demystify the key topics in module development. Because this subject area is so critical to real-world Drupal development, and because the concepts can be quite intimidating to neophytes, any presentation of it must proceed at a reasonable pace, with clear explanation of how each aspect relates to the next. Like similar discussions in other Drupal books, this one begins quite approachable, but becomes more daunting, with a few places where readers will likely be perplexed — such as the hook_form_alter() discussion (page 411), which doesn't seem to match the resultant HTML. Yet this is such a challenging subject area that entire books have been devoted to it, and this one ventures into areas untouched by other books, such as how to create new database tables. Drupal coding standards are presented, although apparently not always followed in the example code (e.g., preceding internal function names with underscores). Part V is rounded out with chapters on porting modules to Drupal 7, writing "glue" modules, performing functional testing, and writing extendable/API modules.
Part VI, "Advanced Site-Building Topics", consists of ten chapters covering a variety of topics: building an online store using Commerce module (authored by the project's founder and lead, Ryan Szrama); Drush (which overlaps with Chapter 2); caching and storage mechanisms (MySQL and MongoDB); RDFa and the Semantic Web; Drupal's routing system; Drupal's internal operations for presenting a requested page; Solr module; UX enhancements in Drupal 7; completing the book's website; and Drupal distributions. All of the information and guidance appears correct, except for a couple problems: The instructions (page 568) to install Commerce Physical Product module, which does not have a Drupal 7 release, as of this writing, and certainly as of the book's publication date. Drune is a music player used as an example throughout Chapter 34, but its website, drune.org (pages 805 and 817), appears to be dead at this time.
Throughout this book, one will find a strong sense of community, with frequent encouragement for the reader to participate and contribute. This is evidenced by Part VII, which comprises four chapters that present: Drupal's history, how to make a living as a Drupal developer, how to maintain a contributed project, and further thoughts on how to contribute to the overall Drupal community. The book concludes with Part VIII, consisting of nine appendices, most of which focus on how to install Drupal on various platforms. This part is strangely titled "Appendix", yet contains multiple appendices (more scope creep?).
Given the somewhat stunning length of this book, its multitude of authors, and its wide coverage of most aspects of Drupal, it should be expected that the book has both strengths and weaknesses. Consider first that latter category. The authors and publisher should have sought ways to reduce the length of the book. For instance, the overview of PHP in Chapter 18 is not needed for this book's audience, and could be replaced by references to outside, more-detailed resources. The same is true of the section on Drupal coding standards. The book does not need to be made any longer than it already is, without good reason. Speaking of which, most of the longer chapters end with summaries, which are not worth the extra space taken up. Drupal's hook system is explained in at least three different chapters, and Git in two. The many authors should have been aware of this, had they been referencing the book's website, which was presumably built before the text describing it was written. Furthermore, the publisher and its chosen technical reviewers should have also spotted this.
The remarkably large number of authors is probably the primary reason for the book's noticeable unevenness, from one chapter to the next, in the quality of the writing — including the clarity of the explanations, which is arguably the most important factor. In a book written by advanced Drupal developers, it is to be expected that they will use Drupal-specific terminology. That is fine, but such terms should be defined at least once, before encountered by any readers unfamiliar with them. For instance, page xxxv alone mentions "d.o", "D8", and "contrib" — all meaningless to someone learning Drupal. There are places in the text where the descriptions do not match the corresponding screenshots (e.g., the "Required field" on page 18), and where, in the narrative, the lack of quotation marks around field labels makes it jarring and difficult to understand (e.g., throughout Chapter 8). There are some inconsistencies in spelling (e.g., "web site" and "website", even in the same sentence, on page lii), some inconsistencies in italicizing menu links (e.g., page 13), some misused phrases (e.g., "cannot be understated", on pages lix and 225, when "cannot be overstated" was called for), some baffling allusions (e.g., "aiee-the-alligator-is-going-to-get-me", on page 492), curly quotes in the code (e.g., pages 277 and 356-9), a repeated paragraph (page 507), an oxymoron ("libertarian communism"; xlvi), and the obligatory conflation of "depreciated" and "deprecated" (page 495) found in countless programming books.
This book contains numerous errata: "co-maintainer [f]or Drupal 7" (page xxxiv), "and." (xxxv), "bi-lingual" (xxxviii), "able [to] handle" (xlix), "don' think" (lv), "criteria[:] type" (lviii), "able [to] fill" (11), "th[r]ough the" (14), "an a" (19), "ask question questions" (29), "install [the] X-ray" (38), "You […] requests nuggets" (49), "you want to you" (56), "on [the] system" (57), "menu of option[s]" (57), "Rather [than] saving" (57), "menu(" (58), "you[r] Views" (59), "These setting[s]" (61), "that what" (66; should read "than what"), "might for use" (67), "you would chose" (67), "the next sort criteria" (67; should read "the next sort criterion"), "by click[ing]" (74), "you are make" (85), and "have [to] click" (85). At this point, not even 8% of the way in, I stopped recording them — although an amusing one is worth mentioning: "gather shook information" (452). Lastly, how did "Drurpal.org" (854) make it past the spelling check? It turns out that the entire book is peppered with such errors, and that first batch was merely the beginning. It is difficult to believe that so many obvious errata could have made it through any professional copyediting process.
Readers who are following along, and likely using the latest version of Drupal (7.8 as of this writing), will notice some differences between what they see on their screens and what is shown in the book's screenshots — most if not all of which are based upon Drupal 7.0. This is especially noticeable in Chapter 3, which covers Views, a module affected by ongoing enhancement. For instance, Views exporter submodule (page 52) is now gone; "Access all views" (page 53) has been altered; "Display Status" (page 62) is gone; there are no broken link icons to indicate overrides; "views/edit" (in the URL, page 71) is now "views/view"; and the Fields configuration dialog (page 75) is different. Fortunately, none of these cases of obsolescence should have any impact on the value of the information as a whole.
On the positive side of the ledger, this book offers much to be commended. As with any worthwhile programming book, this one makes extensive use of code snippets and screenshots to illustrate concepts discussed. These appear to be correct, except in the flowchart of Figure 30-3, where the conditional symbol's arrows are missing values. The text contains some welcome humor (e.g., a kittens photo request, on page 43) and some apt phrases (e.g., Permission module's "wall of checkboxes", on page 156). Some of the chapters were written by the contrib module developers/maintainers, i.e., those who arguably know those modules best. This is unique among the growing list of Drupal books, in that it devotes entire chapters to topics neglected by its competitors — such as documentation, installation profiles, module porting, Drush, Git, and working profitably as a Drupal professional. Some of this information emphasizes the value of project management (both for your individual projects, and Drupal as a whole).
On balance, the pluses outweigh the minuses. The book has a lot of good information, and many of the problems stem from sloppy writing that should have been caught by the publisher's editing team. It may not be the best source for some key subject areas, such as security or site building options. But if you seek a sole source that offers more information in total, then this is your book. For some topics — such as upgrading Drupal, crafting and testing modules, building installation profiles, and the inner secrets of the menu system — it goes into far more detail than any other. Definitive Guide to Drupal 7 is an impressive attempt to be just that, and no other single book currently matches it.