Seven Web Frameworks in Seven Weeks Adventures in Better Web Apps

296 Pages·2014·7.77 MB·English

by  Jack Moffitt

Download from Wow! eBook <www.wowebook.com>
Download from Wow! eBook <www.wowebook.com>
Early Praise for Seven Web Frameworks in Seven Weeks
The title implies a breadth-first analysis of some fairly disparate technologies, but
there is a surprising amount of depth here, more than enough to emphasize the
essential qualities of each one. If you’re a polyglot, or aspire to be, this book is a
very large ball of awesome.
➤ Jim Crossley
Immutant core team member; principal software engineer, Red Hat
Objective and clear. More than an introduction, it’s a head start! Just as wide
and as deep as any modern developer would like. I definitely recommend it.
➤ Pablo Aguiar
Software engineering consultant
This book is great fun. The authors guide you quickly through each framework,
in each case giving you a fast but clear, coherent, and surprisingly detailed taste
that includes major features, design philosophy, implementation, and testing,
plus hints for further investigation. Two JavaScript frameworks, one Ruby, one
Haskell, two Clojure, and one Erlang. If you like web programming, you’re going
to enjoy this book.
➤ Giles Bowkett
Experienced developer and well-known blogger
I thoroughly enjoyed reading the book. In fact, the Yesod chapter even gave me
fresh ideas on how to expose non-Haskellers to the strengths of a strong type
system.
➤ Michael Snoyman
Creator of Yesod; lead software engineer, FP Complete
Download from Wow! eBook <www.wowebook.com>
Seven Web Frameworks in Seven Weeks
Adventures in Better Web Apps
Jack Moffitt
Fred Daoud
The Pragmatic Bookshelf
Dallas, Texas • Raleigh, North Carolina
Download from Wow! eBook <www.wowebook.com>
Many of the designations used by manufacturers and sellers to distinguish their products
are claimed as trademarks. Where those designations appear in this book, and The Pragmatic
Programmers, LLC was aware of a trademark claim, the designations have been printed in
initial capital letters or in all capitals. The Pragmatic Starter Kit, The Pragmatic Programmer,
Pragmatic Programming, Pragmatic Bookshelf, PragProg and the linking g device are trade-
marks of The Pragmatic Programmers, LLC.
Every precaution was taken in the preparation of this book. However, the publisher assumes
no responsibility for errors or omissions, or for damages that may result from the use of
information (including program listings) contained herein.
Our Pragmatic courses, workshops, and other products can help you and your team create
better software and have more fun. For more information, as well as the latest Pragmatic
titles, please visit us at http://pragprog.com.
The team that produced this book includes:
Bruce A. Tate (series editor)
Jacquelyn Carter (editor)
Potomac Indexing, LLC (indexer)
Molly McBeath (copyeditor)
David J Kelly (typesetter)
Janet Furlow (producer)
Juliet Benda (rights)
Ellie Callahan (support)
Copyright © 2014 The Pragmatic Programmers, LLC.
All rights reserved.
No part of this publication may be reproduced, stored in a retrieval system, or
transmitted, in any form, or by any means, electronic, mechanical, photocopying,
recording, or otherwise, without the prior consent of the publisher.
Printed in the United States of America.
ISBN-13: 978-1-93778-563-5
Encoded using the finest acid-free high-entropy binary digits.
Book version: P1.0—January 2014
Download from Wow! eBook <www.wowebook.com>
Contents
Foreword . . . . . . . . . . . . . vii
Acknowledgments . . . . . . . . . . . ix
Preface . . . . . . . . . . . . . . xi
1. Sinatra . . . . . . . . . . . . . . 1
A Simple Domain-Specific Language 1
Day 1: Building a Bookmarking Application 2
Day 2: Creating Views 11
Day 3: Adding Features 22
Wrapping Up 32
2. CanJS . . . . . . . . . . . . . . 35
What Makes CanJS Unique? 35
Day 1: Building Objects and Synchronizing Changes 37
Day 2: Creating Controllers 48
Day 3: Working with Models 57
Wrapping Up 71
3. AngularJS . . . . . . . . . . . . . 73
The Big Picture 73
Day 1: Using Dependency Injection 75
Day 2: Creating Controllers and Views 90
Day 3: Building Filters and Routes 101
Wrapping Up 112
4. Ring . . . . . . . . . . . . . . 115
Introducing Ring 115
Day 1: Basic Towers 116
Day 2: Patterns of Bricks 133
Download from Wow! eBook <www.wowebook.com>
Contents • vi
Day 3: Other Ways to Build 142
Wrapping Up 151
5. Webmachine . . . . . . . . . . . . 155
Introducing Webmachine 155
Day 1: HTTP Request as State Machine 157
Day 2: Building Apps 168
Day 3: Illuminating HTTP’s Dark Corners 182
Wrapping Up 194
6. Yesod . . . . . . . . . . . . . . 197
Introducing Yesod 197
Day 1: Data You Can’t Get Wrong 198
Day 2: Views, Forms, and Auth 208
Day 3: Rumbling Along 219
Wrapping Up 231
7. Immutant . . . . . . . . . . . . . 233
Introducing Immutant 233
Day 1: Beyond the Web Basics 235
Day 2: Building Data Pipelines 245
Day 3: Polyglot Apps 256
Wrapping Up 267
8. Wrap-Up . . . . . . . . . . . . . 269
Key Ideas 269
Happy Exploring 273
A1. Bibliography . . . . . . . . . . . . 275
Index . . . . . . . . . . . . . . 277
Download from Wow! eBook <www.wowebook.com>
Foreword
In 2003, I took my family to Durango, Colorado, where we rode on the
Durango & Silverton train. The narrow gauges of the railroad once served
well against the narrow red sandstone cliffs, where every inch of space was
at a premium. These days, the train is a relic of the past, rendered obsolete
by cars and planes that are safer and more efficient. Time marches on.
Today, too, we witness revolution. Single-core computers are dead or dying.
True, their multicore descendants are technical marvels. They also represent
a tremendous technical challenge. The languages we used to depend on do
not work as well as they once did. As a result, we are seeing a new generation
of languages emerge. So far, no one has been kind enough to declare a winner.
Against this backdrop in 2010, I wrote Seven Languages in Seven Weeks. In
truth, I didn’t expect it to sell many copies. After all, it was a book about
languages in a Java world; a book about programming paradigms in a time
where everything was object oriented. Still, programmers sensed the danger
of our stagnating skills and embraced the concept that learning programming
languages for the sake of learning them can make you smarter and better able
to cope with change. The book was a resounding success.
Three years later, there’s still no clear leader, though functional programming
is starting to gain traction. We’re finding that the multicore wafer tossed into
our virtual pond years ago has created waves that are increasing in size and
velocity. We need more than inheritance to organize our code. We need robust
frameworks on the client to handle the robust development that is happening
there. And we need true concurrent frameworks to take full advantage of their
concurrent languages.
It’s just not enough to lay wider tracks over the narrow tracks we used
last year.
In this book, Fred and Jack will show you the leading edge of people who are
reinventing the way web development should be done. You’ll see a traditional
object-oriented framework called Sinatra. You’ll move on to the client side,
Download from Wow! eBook <www.wowebook.com> report erratum • discuss
Foreword • viii
where exciting things are happening with JavaScript. You’ll take a tour of
CanJS and AngularJS to see how to do full, rich client-side development.
Next, you’ll swing back to the server side to see what’s happening in functional
languages. You’ll encounter two Clojure frameworks in the minimalist Ring
and the robust Immutant. You’ll see a state machine–based design in Erlang
called WebMachine. If those aren’t enough to blow your mind, you’ll find the
incredibly powerful Haskell framework called Yesod.
The “Seven in Seven” books are designed to expand your mind. I am
extremely proud to bring you this next installment, Seven Web Frameworks
in Seven Weeks. It’s my sincerest hope that this book will take you beyond
whatever tracks are holding you back.
Best regards,
Bruce Tate
CTO, icanmakeitbetter.com
Download from Wow! eBook <www.wowebook.com> report erratum • discuss
Acknowledgments
We would like to thank the team at the Pragmatic Bookshelf for making this
book possible. Thanks especially to Jackie Carter, our editor, for all of her
expertise and tireless efforts to make this book better and for bringing it to
the finish line. Thanks also to Bruce Tate—we are both fans of his book, and
we are honored to follow in his footsteps. Thank you, Andy Hunt and Dave
Thomas, for creating such a great environment in which to write about the
technical subjects that we all find fascinating.
Thanks to the technical reviewers who contributed their expert advice on
each framework: Konstantin Haase (Sinatra), David Luecke (CanJS), Miško
Hevery (AngularJS), James Reeves (Ring), Justin Sheehy (Webmachine),
Michael Snoyman (Yesod), Jim Crossley and Toby Crawley (Immutant) and
to the reviewers who offered their comments and suggestions for various
chapters of the book: Kimberly Hagen, Kevin Wiley, Pablo Aguiar, Mick
Thompson, Christopher Zorn, Nathaniel Schutta, and Aaron Bedra.
We would not have such innovative frameworks to write about were it not for
their creators: Blake Mizerany, Justin Meyer, Miško Hevery, Adam Abrons,
Justin Sheehy, Andy Gross, Mark McGranaghan, James Reeves, Jim Crossley,
Toby Crawley, Michael Snoyman, and their respective teams and contributors.
Thanks also to the readers who contributed to the beta-book process on the
errata page; you have helped make this book better.
From Jack: I’d like to thank my wife, Kim, for encouraging me to write
another book, being a sounding board for my ideas, and spending time
reviewing the book. Thanks also to my two children—Beatrix and Jasper—
who provided many happy distractions. I’d also like to thank Sean Johnson,
who introduced me to Bruce, which got the whole project started.
From Fred: Thanks to my wife, Nadia, for being such a beautiful person in
every way. Life is everything with you. Thanks to Lily and Ruby for adding so
much fun and excitement to our family!
Download from Wow! eBook <www.wowebook.com> report erratum • discuss