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title: "Book Review: The Merb Way"
content-type: article
timestamp: 1258452936
tags: "ruby|books|review"
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<p>When I first picked up this book I was surprised by its length. Somehow, after reading <a
		href="/articles/the-rails-way-review">The Rails Way</a>, I got stuck in my mind that <a
		href="http://my.safaribooksonline.com/9780321601636">The Merb Way</a> had to be almost equally voluminous.
	Instead, this book is about 300 page long, roughly as long as the sum of the chapters devoted to
	<em>ActiveRecord</em> in Obie Fernandez's acclaimed Rails bible.
</p>
<p>Apparently it only takes 300 pages to describe a web framework nowadays! I couldn't help but feeling a bit
	skeptical at first. Even in the foreword, Obie Fernandez presents the book &ndash; and the whole <a
		href="http://www.merbivore.com">Merb</a> framework &ndash; with some initial skepticism: isn't Ruby on
	Rails enough? Why do we need yet another Ruby web framework? And above all, seeing that Merb is going to eventually
	be <a href="http://weblog.rubyonrails.org/2008/12/23/merb-gets-merged-into-rails-3">merged into Rails 3</a>, why on
	Earth do we need a book about Merb, <em>now</em>?</p>
<p>Needless to say, Foy Savas proved that both Merb and its book cannot be dismissed just like that.</p>
<h3>Getting started</h3>
<p style="float:right;"><img src="/images/pictures/therailsway.jpg" alt="" /></p>
<p>The book starts with the original <a href="http://pastie.org/14416">Merb Pastie</a>, a single page of Ruby code able
	to sort out <span class="caps">HTTP</span> requests, dispatch them to the appropriate controllers and render a web
	page. This piece of code is enough to convey what Merb is: a new breed of web framework, almost as simple as it can
	get but very poweful and flexible at the same time.</p>
<p>As you start diving in through the first chapter, you realize you're reading about a <em>Hacker's Web
		Framework</em>. That's precisely what Merb is: a very versatile tool to get the job done, in the simplest
	way possible. Similarly, <em>The Merb Way</em> immediately feels like a <em>Hacker's Handbook</em> rather than
	an ordinary guide on how to develop web applications. You won't learn what <span class="caps">MVC</span> is by
	reading this book, and don't expect to be taught what a <em>mixin</em> is; you are reading a book about a Ruby
	web framework that was born after the <em>Rails Revolution</em>, so it is safe (for the author) to assume that:</p>
<ul>
	<li>You know the Ruby programming language</li>
	<li>You know what Ruby on Rails is and you tried it out, at the very least</li>
</ul>
<p>The first few chapters are about the core functionalities provided by an an <span class="caps">MVC</span> framework:
	after a comprehensive first chapter about Merb's fundamentals (from the layout of a Merb application to an
	overview of Merb internals) you are quite abruptly &#8220;introduced&#8221; to routing, controllers, views and
	models. These chapters do not aim to provide a comprehensive description of each component, they simply tell you:
	<em>here's how Merb does this</em>.
</p>
<p>Out of the first five chapters, favorite is definitely the one about <em>Models</em>. Although Merb is <span
		class="caps">ORM</span>-agnostic, DataMapper is the <em>de facto standard</em> for Merb applications, and it
	fully embrace the framework's design and extreme flexibility without being <em>in the way</em> of your
	code.<br />
	Foy does an excellent job in this chapter by strategically describing DataMapper's code from the top to the
	very bottom, from the highest abstractions to raw <span class="caps">SQL</span> code, using a plethora of snippets
	taken from the actual Merb code.</p>
<h3>It's about how Merb works, not how to work with Merb</h3>
<p>After reading the <em>Models</em> chapter I decided to go back and re-examine the previous chapters. I didn't
	notice until then, but the author sneakily <em>smuggled</em> a consistent amount of Merb source code into this book.
	This is rather unusual for books about web frameworks: they normally tell you how to use the framework, not how it
	was built! While this can be disappointing for people used to read Rails books, it came as a very pleasant surprise
	to me.</p>
<p>About 40-50% of this entire book (and I'm not exaggerating) is Ruby source code. In a good way, it feels like a
	collection of strategically-positioned code snippets glued together with explanations of the most tricky bits and
	digressions on how the framework was <em>designed</em>. In other words, it probably contains just enough text to
	make sure that the average reader understands the code, but remember that the <em>average reader</em> of this book
	must know Ruby failry well.</p>
<p>There is no pointless prose in this book, no explanations of obvious methods, no fancy words, no useless boasting on
	how cool the framework is: just an objective description of how Merb works and of the key design decisions behind
	it. If I may, the only thing that doesn't feel quite right with this book is its title: <em>Merb
		Internals</em> would have been a better choice. Once you realize this, the book suddenly makes sense, and can
	even make you a better Ruby programmer.</p>
<p><em>The Merb Way</em> does an excellent job in describing how to design a web framework, or any real-world Ruby
	application for that matter. It teaches you that modularity is the key to flexibility by showing how the Merb stack
	is organized. Sure, it doesn't teach you how to create a blog in five minutes, but perhaps a thorough
	explanation of how anthentication is implemented (Chapter 9) will actually be useful in two months time, when
	you'll have to create your own Merb plugin from scratch.</p>
<h3>Some constructive criticism</h3>
<p>The idea behind this book is clever but a bit dangerous. I flipped through the pages in front of my wife and asked
	her what was wrong with it. <em>&#8220;There's too much code!&#8221;</em> she said, without hesitation.
	Precisely.</p>
<p>It is damn good Ruby code, but sometimes you wish there was more text describing how to use it in practice. Or maybe
	some code examples on <em>using</em> the framework on a real-world application. Not a chance. Of all that holy code,
	there's not much featuring something other than Merb itself. Basically the exact opposite of all the other
	books about Rails or other web frameworks!</p>
<p>Even accepting the fact that you are not reading a book about developing web applications, there are two more things
	which could be improved:</p>
<ul>
	<li>Merb's design is very intriguing, and you grasp the essentials by reading this book, but a few diagrams
		here and there and more in-depth digressions on the subjects would have been nice.</li>
	<li>Besides DataMapper, what I really wanted to read about were Slices and Parts &ndash; unfortunately the chapters
		about them are far too short and shallow. The reasoning behind this is that <em>their future may be
			uncertain</em> due to the Rails 3 merge. Pity.</li>
</ul>
<h3>Conclusion</h3>
<p>The death of Merb has been greatly exaggerated. Too bad I <a href="/articles/take-back-your-site-with-nanoc/">gave up
		web frameworks altogether</a> for my site, because after reading this book I would have gone for Merb
	<em>today</em> rather than waiting to see the wonders of Rails 3 <em>tomorrow</em>. Even a book with this title
	could have been written in a very different way, I would still recommend it if you want to become a better Ruby
	programmer by learning from the best: Merb code really stands out, even compared to Rails, and Foy Savas does a
	great job presenting and describing it.
</p>