Slashdot Mirror

lkcl tips his in-depth article up at Advogato on the difficulties for the MVC programming model that are introduced by Javascript and AJAX, and solutions for them. He writes: "This article outlines how the MVC concept is made incredibly awkward by the gradual but necessary introduction of Javascript and AJAX. A solution is found in the form of Javascript Compiler Technology such as GWT or Pyjamas (PyPy's JS backend or Rb2Js could be used, with some additional work). The article outlines how and why the traditional MVC patterns are fragmented by Javascript and AJAX, advocating that if a site is programmed purely in a high-level language that is then compiled to Javascript for the Web Browser sections, the same high-level source code can be executed either client-side on the browser, or server-side, or even both, depending on the requirements. The implications of this approach are discussed in depth."

TimHunter writes "I was skeptical when I first saw the title of David Berube's new book, Practical Ruby Gems, from Apress. Do Ruby programmers really need a book devoted entirely to add-on libraries? Most Ruby programmers already know about the RubyGems package management system, and most already have their set of favorite gems. About a third of the way through the book I grudgingly admitted that Rubyists might be able to use this book. After all, even long-time Ruby programmers are unlikely to know about all the gems covered in this book. So then I had a new question. Would I find something in this book that made me say 'I didn't know you can do that with Ruby!'" Read on for the rest of Tim's review. Practical Ruby Gems author David Berube pages 271 publisher Apress rating 8 reviewer Tim Hunter ISBN 1-59059-811-3 summary A survey of useful and interesting Ruby libraries Ruby is an object-oriented programming language in the same family as Perl and Python. The programming language used by Ruby on Rails, Ruby is very popular for writing web applications but also widely used for general-purpose programming tasks. Ruby is open source with a commercially friendly license, and is available for Linux, Mac OS X, and Microsoft Windows. RubyGems is Ruby's system for managing, delivering, and installing third-party libraries and applications. It is similar to Perl's CPAN or the Python Package Manager.

Libraries distributed by RubyGems are called "gems." RubyForge is the central Ruby software repository and the primary distributor of gems. According to sysadmin Tom Copeland, RubyForge currently hosts about 1400 different gems. Of that number, Berube selected 29 useful and interesting libraries for his survey of "practical" gems. All of the gems described in this book work the same on Linux, OS X, and Windows.

Practical Ruby Gems is divided into three parts. Part 1 describes the RubyGems system itself. This part explains how to install the RubyGems software and then use RubyGems to install and manage individual gems. (RubyGems is not part of Ruby's standard distribution, except in the "one-click installer" for Microsoft Windows.) The section entitled "What is require_gem?" in Chapter 3 demonstrates one of the problems with writing technical documentation for a moving target like RubyGems. Practical Ruby Gems describes RubyGems 0.9.0. After the book went to press the RubyGems team released a new version that replaced the 'require_gem' method with a method called simply 'gem'. Currently all uses of 'require_gem' generate a warning message. (The remedy for this mistake is simple: attach a yellow sticky with the words "s/require_gem/gem/g" to page 20.) This is really a nitpick, though. Generally the text and examples in the book work as well for the new release as they did for 0.9.0.

Part 2 is by far the largest and has a chapter devoted to each of the 29 gems. The chapters in this part share a common structure. After a short introduction to the gem, there is a section entitled "How Does It Work?" which explains the purpose of the gem and how it's used. Frequently this section includes a small example. "How Does It Work?" is followed by a complete example script. Then, "Dissecting the Example" steps through each part of the example, explaining how it works and pointing out important classes and methods. The examples frequently combine two or more gems, such as the example for pdf-writer, which also uses the net-sftp gem, and the example for the mongrel web server gem, which also uses the Camping web micro-framework gem.

The examples — always practical, frequently interesting, at least to a geek like me — are the heart of the book. Berube said that "no one wants to pay to read a chapter that regurgitates [the gem's built-in documentation]....I wanted to write a book that you could take the examples and actually be interested in what they accomplished." For instance, Chapter 6 describes the BlueCloth text-to-HTML conversion gem. The example in this chapter is a script that converts lightly marked-up text to PDF by combining BlueCloth with html2ps and ghostscript. Chapter 12 describes the yahoofinance gem, a library for retrieving stock quotes using the Yahoo! Finance API. The example for this library combines yahoofinance with the fxruby GUI library to produce a rudimentary stock ticker in less than 100 lines of code. (The source code for all of the examples in the book can be downloaded from the Apress web site.)

But not every example is perfect. Several of the examples rely on MySQL, which I found a chore to install. I wish Berube had chosen a simpler data base for these examples. I never did get the Camping example to run successfully. I suspect the problem was caused by some change to a gem introduced after the book went to press.

In Chapter 22 I got my "you can do that with Ruby?" moment. This chapter explains runt, a Ruby library for creating "temporal expressions," objects that describe dates that reoccur, such as "every Thursday" or "the last Thursday of every month." The example combines runt with linguistics, a small gem that extends some of the Ruby core classes with methods that support such things as pluralization and conversion from numbers to words. The result is a program that lists a set of dates expressed as "the 3rd Mondays of 2026." I was impressed by both gems, not only for the functionality they provide but by their natural and elegant interfaces as expressed in the example script. I not only learned about two very practical Ruby gems, but something about Ruby programming itself. This particular example may not strike everybody the way it did me, but I believe that most readers will find an equally pleasant surprise.

Part 3 is a tiny, advanced topics section which describes how to create and distribute your own Ruby gems and how to run a private gem server on a local network.

Practical Ruby Gems is not for the novice. Berube assumes that his reader is familiar with programming in general and Ruby specifically, and is also familiar with the operating system in which Ruby is running. This is an appropriate assumption because Practical Ruby Gems will be most useful to readers who are serious about programming Ruby, such as professionals or serious amateurs, or those would like to become professionals or serious amateurs.

Practical Ruby Gems is available in PDF format from the Apress web site at about half the price of the paper book.

I have been programming Ruby as a hobby for over 5 years. I am the maintainer of RMagick, one of the gems reviewed in this book. Apress gave me a review copy of Practical Ruby Gems, but otherwise I have no connection to the author or publisher.

You can purchase Practical Ruby Gems from amazon.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.

TimHunter writes "I was skeptical when I first saw the title of David Berube's new book, Practical Ruby Gems, from Apress. Do Ruby programmers really need a book devoted entirely to add-on libraries? Most Ruby programmers already know about the RubyGems package management system, and most already have their set of favorite gems. About a third of the way through the book I grudgingly admitted that Rubyists might be able to use this book. After all, even long-time Ruby programmers are unlikely to know about all the gems covered in this book. So then I had a new question. Would I find something in this book that made me say 'I didn't know you can do that with Ruby!'" Read on for the rest of Tim's review. Practical Ruby Gems author David Berube pages 271 publisher Apress rating 8 reviewer Tim Hunter ISBN 1-59059-811-3 summary A survey of useful and interesting Ruby libraries Ruby is an object-oriented programming language in the same family as Perl and Python. The programming language used by Ruby on Rails, Ruby is very popular for writing web applications but also widely used for general-purpose programming tasks. Ruby is open source with a commercially friendly license, and is available for Linux, Mac OS X, and Microsoft Windows. RubyGems is Ruby's system for managing, delivering, and installing third-party libraries and applications. It is similar to Perl's CPAN or the Python Package Manager.

Libraries distributed by RubyGems are called "gems." RubyForge is the central Ruby software repository and the primary distributor of gems. According to sysadmin Tom Copeland, RubyForge currently hosts about 1400 different gems. Of that number, Berube selected 29 useful and interesting libraries for his survey of "practical" gems. All of the gems described in this book work the same on Linux, OS X, and Windows.

Practical Ruby Gems is divided into three parts. Part 1 describes the RubyGems system itself. This part explains how to install the RubyGems software and then use RubyGems to install and manage individual gems. (RubyGems is not part of Ruby's standard distribution, except in the "one-click installer" for Microsoft Windows.) The section entitled "What is require_gem?" in Chapter 3 demonstrates one of the problems with writing technical documentation for a moving target like RubyGems. Practical Ruby Gems describes RubyGems 0.9.0. After the book went to press the RubyGems team released a new version that replaced the 'require_gem' method with a method called simply 'gem'. Currently all uses of 'require_gem' generate a warning message. (The remedy for this mistake is simple: attach a yellow sticky with the words "s/require_gem/gem/g" to page 20.) This is really a nitpick, though. Generally the text and examples in the book work as well for the new release as they did for 0.9.0.

Part 2 is by far the largest and has a chapter devoted to each of the 29 gems. The chapters in this part share a common structure. After a short introduction to the gem, there is a section entitled "How Does It Work?" which explains the purpose of the gem and how it's used. Frequently this section includes a small example. "How Does It Work?" is followed by a complete example script. Then, "Dissecting the Example" steps through each part of the example, explaining how it works and pointing out important classes and methods. The examples frequently combine two or more gems, such as the example for pdf-writer, which also uses the net-sftp gem, and the example for the mongrel web server gem, which also uses the Camping web micro-framework gem.

The examples — always practical, frequently interesting, at least to a geek like me — are the heart of the book. Berube said that "no one wants to pay to read a chapter that regurgitates [the gem's built-in documentation]....I wanted to write a book that you could take the examples and actually be interested in what they accomplished." For instance, Chapter 6 describes the BlueCloth text-to-HTML conversion gem. The example in this chapter is a script that converts lightly marked-up text to PDF by combining BlueCloth with html2ps and ghostscript. Chapter 12 describes the yahoofinance gem, a library for retrieving stock quotes using the Yahoo! Finance API. The example for this library combines yahoofinance with the fxruby GUI library to produce a rudimentary stock ticker in less than 100 lines of code. (The source code for all of the examples in the book can be downloaded from the Apress web site.)

But not every example is perfect. Several of the examples rely on MySQL, which I found a chore to install. I wish Berube had chosen a simpler data base for these examples. I never did get the Camping example to run successfully. I suspect the problem was caused by some change to a gem introduced after the book went to press.

In Chapter 22 I got my "you can do that with Ruby?" moment. This chapter explains runt, a Ruby library for creating "temporal expressions," objects that describe dates that reoccur, such as "every Thursday" or "the last Thursday of every month." The example combines runt with linguistics, a small gem that extends some of the Ruby core classes with methods that support such things as pluralization and conversion from numbers to words. The result is a program that lists a set of dates expressed as "the 3rd Mondays of 2026." I was impressed by both gems, not only for the functionality they provide but by their natural and elegant interfaces as expressed in the example script. I not only learned about two very practical Ruby gems, but something about Ruby programming itself. This particular example may not strike everybody the way it did me, but I believe that most readers will find an equally pleasant surprise.

Part 3 is a tiny, advanced topics section which describes how to create and distribute your own Ruby gems and how to run a private gem server on a local network.

Practical Ruby Gems is not for the novice. Berube assumes that his reader is familiar with programming in general and Ruby specifically, and is also familiar with the operating system in which Ruby is running. This is an appropriate assumption because Practical Ruby Gems will be most useful to readers who are serious about programming Ruby, such as professionals or serious amateurs, or those would like to become professionals or serious amateurs.

Practical Ruby Gems is available in PDF format from the Apress web site at about half the price of the paper book.

I have been programming Ruby as a hobby for over 5 years. I am the maintainer of RMagick, one of the gems reviewed in this book. Apress gave me a review copy of Practical Ruby Gems, but otherwise I have no connection to the author or publisher.

You can purchase Practical Ruby Gems from amazon.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.

Coryoth writes "Design by Contract, writing pre- and post-conditions on functions, seemed like straightforward common sense to me. Such conditions, in the form of executable code, not only provide more exacting API documentation, but also provide a test harness. Having easy to write unit tests, that are automatically integrated into the inheritance hierarchy in OO languages, 'just made sense'. However, despite being available (to varying degrees of completeness) for many languages other than Eiffel, including Java, C++, Perl, Python, Ruby, Ada, and even Haskell and Ocaml, the concept has never gained significant traction, particularly in comparison to unit testing frameworks (which DbC complements nicely), and hype like 'Extreme Programming'. So why did Design by Contract fail to take off?"

Tim Hunter writes "Hal Fulton's The Ruby Way, Second Edition doesn't try to be the only book a Ruby programmer needs. It tries to be a book every serious Ruby programmer needs, and it succeeds. The Ruby Way is a book about programming with Ruby, the object-oriented programming language from Japan. Ruby is free software and runs on Linux, Microsoft Windows, Apple OS X, and other operating systems. It is available for download from its web site, www.ruby-lang.org or its companion site www.rubyforge.org. Read the rest of Tim's review. The Ruby Way, Second Edition author Hal Fulton pages 839 publisher Addison-Wesley rating 9 reviewer Tim Hunter ISBN 0-672-32884-4 summary A task-oriented book about the Ruby programming language

I read the first edition of The Ruby Way when it was published in 2002, not long after I starting programming in Ruby. I was a member of the discussion group Fulton organized during the writing of this edition. I am also the author of RMagick, one of the libraries described in this book, and did the technical review of that section.

This is a review of the second edition of The Ruby Way. The first edition described the then-current Ruby syntax and libraries and showed novice Ruby programmers how to perform common programming tasks. In the past four years Ruby has evolved and its community has grown immensely. Consequently, the first edition was starting to look a little long in the tooth and the Ruby community has been eager for the appearance of a new edition. This edition is almost a complete rewrite. Saying that it's 260 pages longer minimizes the actual scope of the changes. There are a dozen new chapters. Some of the new material expands on topics that were present in the older work, like regular expressions and data structures. However, much of the new material covers topics that simply didn't exist 4 years ago, such as Ruby's XML and RSS libraries, RubyGems (Ruby's answer to CPAN), and Rake, the Ruby version of make.

The Ruby Way doesn't try to teach how to program in Ruby. For that, you need Dave Thomas' Programming Ruby: The Pragmatic Programmer's Guide or a similar book. The goal of The Ruby Way is nothing less than describing the universe around the Ruby programming language. In one 800+ page volume, it describes Ruby's design principles, history, syntax, built-in classes, standard libraries, 3rd-party add-on libraries, related development tools, and user community. The examples and Fulton's explanations emphasize Ruby programming best practices, hence the title.

Fulton describes The Ruby Way as an "inverted reference." A typical reference book for a programming language lists the libraries, classes and methods by name, which you can use to discover their purpose. The Ruby Way, on the other hand, groups Ruby's libraries, classes and methods by purpose, from which you can discover their names. Section titles tend to describe tasks, such as "Tokenizing a String" and "Interacting with an IMAP Server". The sections then describe the split method in the String class and the net/imap library, respectively. Several chapters group Ruby libraries by related tasks. For example, Chapter 15 describes Ruby libraries used to process specialized data formats such as XML, RSS, images, and PDF. In this chapter you will learn that XML processing in Ruby is typically done with REXML and that PDF files can be created with PDF::Writer, etc. Organizing topics by purpose or function instead of by name makes it easy to discover what parts of Ruby you need to complete a task.

Unlike many of the 2-inch thick books about programming for sale lately, there is no fat in The Ruby Way. It hits the ground running with an introduction to object oriented programming and a whirlwind tour of Ruby syntax. It covers Ruby's built-in classes in considerable depth. The String class gets an entire chapter, as do regular expressions. Array and Hash rate yet another chapter. Fulton continues with an in-depth survey of Ruby's extensive standard library. Interested in object persistence? Chapter 10 describes Ruby's YAML library. Wondering about unit testing? Go to Chapter 16 to read about the Test::Unit library. One of the most frequently asked questions to the ruby-lang mailing list is "what GUI libraries are there for Ruby?" Chapter 12 supplies sample applications that demonstrate graphical interface libraries such as Ruby/Tk, FXRuby, and QtRuby. Chapter 19 is dedicated to web application development tools ranging from the famous Ruby on Rails to the lesser-known but equally useful Nitro. Chapter 22, "The Ruby Community," tells where other Ruby programmers hang out. Catering to his programmer audience, Fulton peppers each section with code snippets and complete example programs. (The source code for the book can be downloaded from Fulton's web page.)

Although Ruby is thought to be a "Linux-centric" language it also has a large audience in the Microsoft Windows community. Fulton addresses these users' needs with a description of the "One-Click Ruby Installer" for Windows. This description is accompanied by a section about the Ruby libraries available for scripting on Windows. For example, Fulton shows how to open a file dialog box using the Win32OLE library.

Fulton says that he doesn't expect anybody to read his book from front-to-back. Nevertheless The Ruby Way is quite readable and (if not for its considerable weight) would make a good book for browsing while waiting for the bus, or between classes. Some sections contain a surprising amount of general background information, such as the remarkably in-depth description of Unicode in Chapter 4. Not content to simply educate the reader, Fulton continues his practice in the 1st edition of entertaining the reader with thoughtfully chosen quotes, geek humor, and personal observations.

Is there anything not to like about this book? Well, to be perfectly honest I occasionally found myself wondering if sometimes Fulton spread himself too thin. The amount of coverage for individual classes and libraries varies widely. Some of the standard libraries, like REXML, get several pages of description and an accompanying example while others, such as open-uri, get only a cursory introduction and a pointer to the on-line documentation. At 4 pages, the section on Rails is perfunctory and, given the number of very good books already available on the subject, redundant. (Fulton himself says the material is "cursory.") I have to wonder if it isn't there simply because "everybody" expects books about Ruby to say something about Rails. Similarly he devotes a single page to ActiveRecord, which, as a part of Ruby on Rails, is capably documented elsewhere. That page would've been better used to double the number of pages spent on Og, another Ruby ORM which is not so richly documented.

I recommend this book to any programmer who has already learned the basics of Ruby syntax and its built in classes and who wants to learn more about using Ruby to accomplish typical programming tasks. While it will be particularly useful to the novice Ruby programmer, it is a handy reference for Rubyists at any level of experience.

You can purchase The Ruby Way, Second Edition from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.

submitted by Simon Strandgaard writes "When new operating systems gets designed today, great systems such as Amiga, Atari and VMS, seems to get overlooked in regard to their original features not found on other OSes. It might be time to collect and categorize those special unique features under the great/lost ideas wiki, so new OSes don't have to re-invent the wheel and re-innovate." This is all for R.O.S., a "ruby-centric operating system."

submitted by Simon Strandgaard writes "When new operating systems gets designed today, great systems such as Amiga, Atari and VMS, seems to get overlooked in regard to their original features not found on other OSes. It might be time to collect and categorize those special unique features under the great/lost ideas wiki, so new OSes don't have to re-invent the wheel and re-innovate." This is all for R.O.S., a "ruby-centric operating system."

tcopeland writes "RubyForge is a new hosting area for open source Ruby projects. It's powered by the popular GForge fork of SourceForge development. There's even a couple of code snippets up there already."

tcopeland writes "RubyForge is a new hosting area for open source Ruby projects. It's powered by the popular GForge fork of SourceForge development. There's even a couple of code snippets up there already."