We try to keep our books accurate, but sometimes mistakes creep in. This page lists the errors submitted by our astute readers. If you've found a new error, please submit it.

The latest version of the book is P3.0, released almost 2 years ago. If you've bought a PDF of the book and would like to upgrade it to this version (for free), visit your home page.

Key: Typo Tech. Error Suggestion Not a problem Next edition

By default this page displays the errata for the latest version of the book. If you have a previous version, select it here:  

(To find out what version you have, look at the copyright page, a few pages in from the front of the book. If it says (say) 'Second Printing', then here it'll be P2.0. If there are interim PDF releases in that printing, they'll be 2.1, 2.2, and so on.)

PDF Paper Description Found in Fixed in
all
#47945: It would be convenient if the page numbers could be synchronized such that they are always along the outside edge of the page. Some chapters s...more...
P2.1
13-Nov-11
B2.0
0
#51432: Errata error ... on pragprog.com/titles/rails4/errata it says The latest version of the book is P3.2, released about 3 hours ag...more...
B2.0
01-May-13
5
#50965: The command used in the book reads as "rvm install 2.0.0", but this is causing an error saying the version is too confusing. What really help...more...
Sam Ruby says: I can't reproduce this and I haven't seen the problem reported elsewhere.
B1.0
06-Mar-13
B2.0
11
#50948: Editor/IDE notes are outdated: RadRails is now effectively deprecated: "RadRails is now included as part of Aptana Studio 3" as per the footn...more...
B1.0
03-Mar-13
B2.0
13
#51431: re: Agile Web Development with Rails 3.2 (4th edition) ...more...
Sam Ruby says: I just tried these instructions on a fresh virtual machine with Rails 3.2.13: $ rake doc:rails rm -r doc/api Parsing sources... 100% [503/503] ...ant/.rvm/gems/ruby-2.0.0-p0/gems/railties-3.2.13/lib/rails.rb Generating Darkfish format into /home/vagrant/work/dummy_app/doc/api... Files: 503 Classes: 248 ( 123 undocumented) Modules: 276 ( 176 undocumented) Constants: 163 ( 143 undocumented) Attributes: 227 ( 215 undocumented) Methods: 2701 (1142 undocumented) Total: 3615 (1799 undocumented) 50.24% documented Elapsed: 58.4s
B2.0
01-May-13
15

#50971: Mikel Lindsaar has changed the company name from RubyX to reInteractive--Trung LE

B1.0
07-Mar-13
B2.0
16.2
#50441: For next edition, the chapter on deployment via Capistrano needs to be updated: - if you are using RVM, the first two lines in the RVM sectio...more...
P3.0
06-Jan-13
B1.0
19
#50327: Running Windows version Rails 3.2.1. When you attempt to run this new version it fails because of the asset pipeline support that was added, ...more...
Sam Ruby says: Printing 3.0 is for Rails 3.2.3.
P3.0
07-Dec-12
B1.0
20
#50911: "Some browsers (such as Safari) will mistakenly try to interpret some of the templates as HTML" - Safari 6.0.3 renders the Ruby code just fine...more...
B1.0
27-Feb-13
B2.0
28

#50972: My surname LE as in Trung LE is missing the accent, it should be Trung Lê--Trung Lê

B1.0
07-Mar-13
B2.0
28
#50899: Assuming Ubuntu is one of the most popular Linux distribution. The upgrade command does not work on it. $ gem update --system ERROR: Whil...more...
Sam Ruby says: That was removed in the second printing.
P3.0
26-Feb-13
B2.0
29

#50158: Installing on Mac:
sudo port install rb-rubygem
missing s on end - should read:
sudo port install rb-rubygems
--scott macri

Sam Ruby says: Could not find these instructions in any recent printing
P3.0
12-Nov-12
B1.0
31
#50949: (Got page number wrong). Editor/IDE notes are outdated: RadRails is now effectively deprecated: "RadRails is now included as part of Aptana...more...
B1.0
03-Mar-13
B2.0
31
#48875: It seems that every use of the [Add to Cart] button in the PDF version comes across in the mobi ebook version as "ADD ADD CART button" with at...more...
P2.2
03-Mar-12
B2.0
34

#50950: Remove reference to postgres-pr. It's undocumented, and hasn't been updated since Dec 2009.

B1.0
03-Mar-13
B2.0
62
#49738: rails generate scaffold Product \ title:string description:text image_url:string price:decimal The \ only works in a Linux environment. I...more...
Sam Ruby says: I've retested it on a mac and verified it works. Windows is covered by the footnote.
P3.0
24-Aug-12
B1.0
64
#50979: For the paragraph on recommending installing Xcode 4.1 from App Store, I think we should mention that we just need to install Command Line Too...more...
B1.0
07-Mar-13
B2.0
65
#49727: In the image of the web viewer showing an empty product listing, the location field shows "localhost:3000/product". The "s" on the end of pro...more...
P3.0
23-Aug-12
B1.0
66
#50977: OSX 1.0.7+ is known to have issues with UTF-8 input within IRB due to a bug within libreadline that is shipped by default on the platform. The...more...
Sam Ruby says: Went with autolibs as the latest rvm states: Beware, 'rvm pkg ...' is deprecated, read about the new autolibs feature: 'rvm help autolibs'.
B1.0
07-Mar-13
B2.0
70

#50192: for me the cycle method doesn´t work to create alternating background colors.--Adrian

P1.0
22-Nov-12
B1.0
71
#52222: <body class='<%= controller.controller_name %>'> didn't work But when I change it for: <body class="<%= controller.controller_name %>"> ...more...
P3.0
20-Jul-13
71
#52223: <body class='<%= controller.controller_name %>'> didn't work But when I change it for: <body class="<%= controller.controller_name %>"> ...more...
P2.2
20-Jul-13
72

#50374: <table> should say <table class="products">

Sam Ruby says: class="products" is placed on the body element on the previous page
P3.0
13-Dec-12
B1.0
72
#50918: The file products.css.scss has comments /* START_HIGHLIGHT */ and /* END_HIGHLIGHT */. This has the effect of creating an empty products.css ...more...
Sam Ruby says: Works for me with those comments in place (i.e., the generated products.css is not empty). If you see this comment, consider starting a discussion on http://forums.pragprog.com/forums/148 and we can debug this together.
B1.0
28-Feb-13
B2.0
72

#50410: The page rails32/depot_a/app/views/products/index.html.erb linked to on page 72 displays the code in a table, instead of as html--DJH

Sam Ruby says: view source
P3.0
24-Dec-12
B1.0
80
#49524: Validating `:image_url, presence: true`, makes the image_url field required. A few lines down, in the same model, `validates :image_url, allo...more...
Sam Ruby says: This is specifically called out in the prose: "Note that we used the allow_blank" option to avoid getting multiple error messages when the field is blank"
P2.2
14-Jul-12
B1.0
81

#50247: Tests don't pass

Sam Ruby says: works for me
P3.0
04-Dec-12
B1.0
84
#49729: In the paragraph after the 'test "product price must be positive" do' code, third sentence, you mention using the join method to concatenate t...more...
P3.0
23-Aug-12
B1.0
85

#50973: Sublime Text Editor has gained much traction for the past years and has replaced the defacto TextMate. It's good if we could mention Sublime here.--Trung Lê

B1.0
07-Mar-13
B2.0
88
#49901: the seed.rb uses rails.jpg for the product, and the file provided in media.pragprog.com/titles/rails4/code/rails32/depot_a/app/assets/images/ ...more...
Sam Ruby says: I can't find rails.jpg anyplace... the seeds file refers to cs, ruby, and rtp jpg files.
P3.0
30-Sep-12
B1.0
92
#49768: # root :to => 'welcome#index' root to: => 'store#index', as: 'store' Has to be # root :to => 'welcome#index' root :to => 'stor...more...
Sam Ruby says: root to: 'store#index', as: 'store' is correct for Ruby 1.9.2
P2.1
30-Aug-12
B1.0
93

#50978: Please remove paragraph mentioning about postgres-pr library because that lib is very outdated and inactive--Trung Lê

B1.0
07-Mar-13
B2.0
95
#50982: I think we should mention PostgresSQL in 'We installed (or upgraded) the SQLite 3 and MySQL databases' (page 95) and 'MySQL and SQLite adapte...more...
Sam Ruby says: Added encouragement to explore postgresql as well as rbenv, ruby-build, unicorn, and nginx in the Playtime section of the Deployment chapter.
B1.0
07-Mar-13
B2.0
96

#50974: Please replace URL `rvm.beginrescueend.com/` with `rvm.io`--Trung Lê

B1.0
07-Mar-13
B2.0
96

#50983: Please recursively search and replace URL rvm.beginrescueend.com with rvm.io--Trung Le

B1.0
07-Mar-13
B2.0
96
#51260: There shouldn't be a "#" after the comma on line 5 for application.html.erb <!DOCTYPE html> <html> <head> <title>Pragprog Books Online S...more...
B1.0
10-Apr-13
B2.0
96

#50926: Clicking on "Download rails40/depot_e/app/views/layouts/application.html.erb"
does not open in the browser but instead jumps to PDF page 449
--James R Grier

Sam Ruby says: Works for me in both Chrome and Firefox. Can you provide more information on what you are seeing? Meanwhile, the correct link is http://media.pragprog.com/titles/rails4/code/rails40/depot_e/app/views/layouts/application.html.erb
B1.0
01-Mar-13
B2.0
98
#47642: Why don't you teach to use flash standard messages by adding lines like those in the application template? <% flash.each do |key, value| %>...more...
Sam Ruby says: After much thought, I decided to stick with something that is closer to the approach of the templates produced by the scaffolding generator.
P2.0
26-Sep-11
B1.0
98
#49733: There appears to be a problem with the css for the img tag in the banner. When viewing the page in Safari 6.0, the logo image shows up on top...more...
Sam Ruby says: check for #banner.img {float: left} in application.css
P3.0
23-Aug-12
B1.0
98
#49515: '}' missing at the end of the #columns declaration (in the pdf AND on the page code/rails32/depot_e/app/assets/stylesheets/application.css.scs...more...
Sam Ruby says: Double and triple checked. There are 9 open and 9 close braces in that file. #main and #side are nested within #columns. Inside #side, ul, li, and a are nested, which makes a total of five open elements that are closed at the end of the file.
P2.2
12-Jul-12
B1.0
99

#51344: I believe Rails 4 is using the minitest framework now as it has replaced test unit in ruby 1.9+. The book still mentions test unit.--Peter Rhoades

B1.0
20-Apr-13
B2.0
100
#51100: With Task B Validation and Unit Testing in Iteration B2. The directory structure in the project differs to what is described in the book. Whe...more...
Sam Ruby says: It actually is the other way around: with test/unit and test:units are Rails 3.x and below; test/models and test:models is Rails 4.
B1.0
20-Mar-13
B2.0
100
#51391: when adding this to my products_controller_test @update = { :title => 'Lorem Ipsum', :description => 'Wibbles are fun!...more...
Sam Ruby says: Works for me: http://intertwingly.net/projects/AWDwR4/checkdepot-193-32/section-7.1.html. Feel free to bring up on http://forums.pragprog.com/forums/148
B1.0
26-Apr-13
B2.0
101
#49735: The formatting for this page appears to be wrong. After the sentence, "First, let’s take a look at what Rails generated for us:", the rest of...more...
P3.0
23-Aug-12
B1.0
104
#50789: In section 8.5, "What We Just Did," item 3 states: "Add a call to the order() method with the Products controller..." This call to order() wa...more...
P3.0
12-Feb-13
B1.0
107
#51167: Last test("...unique title - i18n") fails. --- expected +++ actual @@ -1 +1 @@ -"translation missing: en.activerecord.errors.messages.take...more...
Sam Ruby says: Should be errors.messages.taken (i.e., no activerecord): http://media.pragprog.com/titles/rails4/code/rails40/depot_c/test/models/product_test.rb Which passes: http://intertwingly.net/projects/AWDwR4/checkdepot/section-7.2.html
B1.0
01-Apr-13
B2.0
108
#50913: "current_cart()..." in the first and second paragraphs should be changed to "set_cart()". "CreateCart module" in the second paragraph should b...more...
B1.0
27-Feb-13
B2.0
111
#50157: Minor nit, second paragraph: says that you pass the product into @cart.line_items.build, then save into an instance variable named @line_item...more...
P3.0
08-Nov-12
B1.0
112
#49736: In the first sentence on the page, you mention adding the new css lines to the rule for .entry. However, the lines were added to the rule for...more...
P3.0
23-Aug-12
B1.0
112
#49905: @line_item = @cart.line_items.build should be: @line_item = @cart.line_items.build(:product_id => product.id) this even fix the AJAX ...more...
P3.0
02-Oct-12
B1.0
113
#49492: the image showing a double add of the "CoffeeScript" title is wrong. It should just be one, despite a refresh (because you're simply refreshin...more...
P2.2
04-Jul-12
B1.0
115
#50519: The book says to rename application.css to application.css.scss. Previously when told to delete public/index.html, the book also listed the Gi...more...
P3.0
24-Jan-13
B1.0
116

#52221: Missing the line "@line_item.product = product" in the controller. Add after the line "@line_item = @cart.add_product(product.id)"--Matías Mascazzini

P2.2
20-Jul-13
118
#49941: related to erratum #49593 When applying the migration: depot> rake db:migrate the following error occurs: "Can't mass assign protected...more...
Sam Ruby says: Printing 3.0 is required in order to use Rails 3.2.3 or later.
P2.2
11-Oct-12
B1.0
118
#49737: In the paragraph right after the code for add_product, the last sentence is worded strangely. It seems that something is missing after the wo...more...
P3.0
23-Aug-12
B1.0
120
#51121: The only edit needed for the line_items_controller.rb is the one noted by the --> arrow pointing to the second line starting "@line_item = ......more...
B1.0
24-Mar-13
B2.0
123
#51250: In reference to Donald Guy's submission #51022 I was able to reproduce this by restarting the rails server between changes instead of keep the...more...
B1.0
06-Apr-13
B2.0
123
#51022: Following along using the same versions (ruby 2.0, rails 4.0beta1), after rolling back the migration (rake db:rollback), I can't see the resul...more...
B1.0
13-Mar-13
B2.0
125

#49445: The "David says" sidebar at the top of the page comes smack in the middle of the code example for line_items_controller.rb--Martin Wehlou

P2.2
17-Jun-12
B2.0
125
#49593: I'm running rails 3.2.3. I received this error when trying to add a book to the cart: Can't mass-assign protected attributes: product ...more...
Sam Ruby says: Printing 3.0 is required in order to use Rails 3.2.3 or later.
P2.2
26-Jul-12
B1.0
128

#51423: The word "has" should be "have" in "they has a lot of useful
information." This is in the admonition to review log files periodically.--Dave Hackett

B1.0
30-Apr-13
B2.0
133
#51164: In the solutions wiki page for "Play Time" that the PDF links to, for Activity 2, the hint says "Hint: add two tests to test/unit/cart_test.rb...more...
B1.0
31-Mar-13
B2.0
134
#49965: I think you wanted to change the source for rails32/depot_k/app/views/carts/show.html.erb to be: <% if notice %> <p id="notice"><%= noti...more...
P3.0
19-Oct-12
B1.0
135
#49227: On page 135 of 737 in iBooks, there should not be a "\" in the following command: rails generate scaffold Product \ title:string descriptio...more...
Sam Ruby says: Please see footnote on this page
P2.2
28-Apr-12
B1.0
136
#49508: Trivially, but annoyingly, Figure 20 splits the line_items controller code started on page 135. Also (trivially) the screenshot of the page ha...more...
P2.2
08-Jul-12
B1.0
136
#49516: You forgot to run rake test:functionals after making these changes (iteration F1)! Most of the tests broke but I was on my own trying to figu...more...
Sam Ruby says: Covered in iteration F6
P2.1
12-Jul-12
B1.0
138
#49409: the alias "j" is used to escape rendered partial for javascript. But "j" is an alias for "json_encode" while here escape_javascript is needed....more...
P2.2
06-Jun-12
B1.0
139

#50975: Please update Footnote [24] to use rvm.io URL instead--Trung Lê

B1.0
07-Mar-13
B2.0
139

#50976: Footnote [25] URL is no longer valid, the correct one is

gembundler.com/v1.3/bundle_exec.html--Trung Lê

B1.0
07-Mar-13
B2.0
139 121

#49579: This did not work...
redirect_to store_url, notice: 'Invalid cart'

So I changed it to:
redirect_to store_index_url, notice: 'Invalid cart'

--Jez

Sam Ruby says: Make sure that config/routes contains as 'store' on the "root to" line. Verify using "rake routes"
P2.2
26-Jul-12
B1.0
141

#53190: I get an error stating that the 'jquery-ui' couldn't be found in the application.js file. Has the reference changed for jQuery UI? --Thomas

P3.0
21-Nov-13
142
#50369: This comparison <% if line_item == @current_item %> will always return false, it doesn't work, because we are comparing to different objects, ...more...
Sam Ruby says: can't reproduce
P3.0
13-Dec-12
B1.0
150 132
#49631: I think something's missing here... <table> ➤ <%= render(cart.line_items) %> I did not get same display with the book (p.136) so I append...more...
Sam Ruby says: I can't reproduce this problem.
P2.2
05-Aug-12
B1.0
151 134
#50355: After "Let’s avoid all of that and replace the original template with code that causes the partial to be rendered:", the code snippet for "ca...more...
P3.0
11-Dec-12
B1.0
152 134

#51251: The file rails32/depot_k/app/assets/stylesheets/carts.css.scss diff the content of the displayed in the book--Francisco Peña

Sam Ruby says: Updated in P3.0
P2.2
06-Apr-13
B2.0
153
#51094: store.js.coffee ➤ $(document).on "page:change", -> ➤ $('.store .entry > img').click -> ➤ $(this).parent().find(':submit').click() The ab...more...
B1.0
19-Mar-13
B2.0
157
#49595: The code segment shown for new.html.erb does not match my existing file at all. This confused me until I realized the code segment is just mis...more...
P2.2
29-Jul-12
B1.0
160
#51354: I could not get tests to pass, or the Checkout button to work without adding the following two lines to the orders_controller.rb: class Ord...more...
B1.0
21-Apr-13
B2.0
162
#49971: In the test fixture line_items.yml, you highlight one line for updating but the entire file listing you have does not match what was generated...more...
Sam Ruby says: Somebody didn't do the second playtime exercise in section 10.3 :-)
P3.0
21-Oct-12
B1.0
164 146

#52037: Name "JQuery" should be "jQuery".--Ing. Martin Bachtík

P2.2
20-Jun-13
164
#51136: the code line <%= render(:partial => "cart_item" , :collection => cart.line_items) %> in the _cart.html.erb files should be the same as in ...more...
Sam Ruby says: No 4th edition printing contains this text.
B1.0
26-Mar-13
B2.0
165
#49972: In the code for orders_controller_test.rb, I only needed to modify the assert_redirected line. The post line was already correct. I am doing...more...
P3.0
21-Oct-12
B1.0
166
#49973: The output from "select * from line_items;" should have 2 rows, the one you showed for the CoffeeScript line item but also one for the Ruby 1....more...
Sam Ruby says: I'm not seeing that here: http://intertwingly.net/projects/AWDwR4/checkdepot-32/section-12.1.html
P3.0
21-Oct-12
B1.0
168
#51247: The text describes selecting params[:order] in the first line, but the example has been updated to use strong params (calling the private orde...more...
B1.0
06-Apr-13
B2.0
169
#50603: There is a syntax error on the second line of the code for who_bought.atom.builder. There needs to be an equals between feed.title and its new...more...
Sam Ruby says: It is correct as is. This is not an assignment, instead it is a method that creates a <title> element in the <feed>.
P3.0
26-Jan-13
B1.0
172
#51099: In the last paragraph on the page you ask the reader to recall a section which they have not even read yet as it is much further on in the boo...more...
Sam Ruby says: Corrected reference to be to Section 8.5, Iteration C5: Caching of partial results
B1.0
20-Mar-13
B2.0
175 160
#50954: I'd suggest you tell to add the before_action callback for the cart (before_action :set_cart, only: [:new, :create]). Otherwise, there will b...more...
B1.0
04-Mar-13
B2.0
175
#49974: In Figure 25, the URL in the location field is localhost:3000/en/orders which probably works if you are running the Rails app behind apache or...more...
P3.0
21-Oct-12
B1.0
176

#50155: I created the file with ruby codes, and run it. but nothing happens to the database--derek

Sam Ruby says: I don't understand this errata.
P3.0
08-Nov-12
B1.0
185
#49975: The integration test generated does not match your listing. It should be: require 'test_helper' class UserStoriesTest < ActionDispatc...more...
P3.0
21-Oct-12
B1.0
190
#49074: [p. 190] Why does this form use ":" after each field label? It doesn't match the other forms, and it looks ugly and broken if there are for...more...
P2.2
06-Apr-12
B1.0
195
#51249: While editing users_controller.rb, you need to change user_params to permit :password and :password_confirmation (and probably disallow passwo...more...
B1.0
06-Apr-13
B2.0
196
#51248: The code example for the new user form omits the class="field" and class="actions" from the divs. Though they are included by the initial scaf...more...
B1.0
06-Apr-13
B2.0
200

#50466: specifically for the value of hashed_password.
...should be...
specifically for the value of password_digest.--T Farrington

P3.0
14-Jan-13
B1.0
211 198
#50958: I'd suggest you to update the user_params private method in the user_controller in order to the controller test to pass (adding the :password ...more...
B1.0
05-Mar-13
B2.0
211
#48213: "Note that we did not choose to put the administrative and session functions inside this scope, because it is not our intent to translate them...more...
P2.1
05-Dec-11
B1.0
221
#50190: Should provide English version of errors.template, or there will be errors in English version. Also it's hard to know what errors.template.bod...more...
Sam Ruby says: English versions are provided for everything that isn't built into Rails. The book prose describes what is being added to the file.
P3.0
21-Nov-12
B1.0
222
#49976: In the code for app/views/orders/_form.html.erb, in Rails 3.2.8, it does appear that you need to use the i18n functions for labels if you want...more...
P3.0
22-Oct-12
B1.0
229

#51226: figure 37 shows
Body Html
not
Hay problemas con los siguientes campos:
--Tim Morgan

B1.0
04-Apr-13
B2.0
231

#51562: "Linux users should have already installed Apache in in Section 1.3, Installing on Linux, on page 6."
The word in is repeated--Daniel Garcia

P2.2
22-May-13
231
#50417: Reading and understanding chapter 16 was sometimes hard. I wasn't always sure whether you were talking about the server or the development mac...more...
P3.0
27-Dec-12
B2.0
233
#50624: As of Mac OS X 10.8, the Web Sharing system preference is no longer included with the operating system. Apache can still be enabled via Termin...more...
P3.0
30-Jan-13
B1.0
234
#50669: I had a lot of problems getting virtual hosts working in Apache. foundationphp.com/tutorials/apache22_vhosts.php is what finally helped me to ...more...
Sam Ruby says: That appears to be instructions on getting Apache running on Windows?
P3.0
03-Feb-13
B2.0
241
#50407: # Deploy with Capistrano ➤ gem 'capistrano' should be # Deploy with Capistrano ➤ gem 'rvm-capistrano' Otherwise when invoking "cap de...more...
P3.0
23-Dec-12
B1.0
242
#49988: In the paragraph after the capify command, you mention the creation of the Capfile and say that we do not need to modify it. You then show th...more...
P3.0
24-Oct-12
B1.0
242
#49989: In the listing of the Capfile, you show the line: Dir['vendor/gems/*/recipes/*.rb','vendor/plugins/*/recipes/*.rb'].each { |plugin| load(pl...more...
P3.0
24-Oct-12
B1.0
243
#50668: If you are using Rails v3.2.11, there will be errors during deployment (when running cap deploy:migrations) with the deploy.rb file as-is. You...more...
Sam Ruby says: Can't reproduce (at least not on Rails 4.0.0.beta1)
P3.0
03-Feb-13
B2.0
244
#50416: The last sentence in the first paragraph reads The :deploy_to may need to be tweaked to match where we told Apache it could find the config/p...more...
P3.0
27-Dec-12
B1.0
246
#50415: In the section "Using Console to Look at a Live Application" it reads # On your server $ cd /home/rubys/work/depot/ $ rails console produ...more...
P3.0
27-Dec-12
B1.0
287

#50894: The block "order" starts with: "SQL that rows ...", which should be "SQL specifies that..."

That is, the word "specifies" is missing.--Björn Peemöller

P3.0
26-Feb-13
B2.0
296
#50788: In the third paragraph (one above title 'Grouping Related Callbacks Together'), the sentence "If you try declaring them as handlers using the ...more...
P2.1
12-Feb-13
B1.0
305
#50919: I believe Rails Observers have been removed from Rails 4. It would be good if this section could be rewritten to expound on how to do things l...more...
Sam Ruby says: Removed subsection on Observers, added a link to Concerns: http://37signals.com/svn/posts/3372-put-chubby-models-on-a-diet-with-concerns
B1.0
28-Feb-13
B2.0
351
#49895: It's missing the equal sign for the form_for on the first line of the get.html.erb view template. it should be: <%= form_for(:picture, url:...more...
P3.0
29-Sep-12
B1.0
383

#51150: Replace current_cart with set_cart and SetCart module with CurrentCart--Trung Lê

B1.0
29-Mar-13
B2.0
383

#51151: Please explain the usage of concerns here, as a beginner, they would get very confused--Trung Lê

Sam Ruby says: As explained in the text, a concern is nothing more than a way to share common code (even as little as a single method) between controllers. If you feel this is not enough, consider starting a discussion on the forum, and we can work through this. http://forums.pragprog.com/forums/148
B1.0
29-Mar-13
B2.0
384

#51153: It is highly recommended to use #find_by method in Rails 4. Please replace find_by_product_id with find_by(product_id: id)--Trung Lê

B1.0
29-Mar-13
B2.0
399

#51154: " ...“ordered pairs of product_ids and quantity.”

Change product_ids to product_id--Trung Lê

B1.0
29-Mar-13
B2.0
430
#50781: "You can see the list of middlewares that Rails provides for Rails applications using the command rake middleware." That should probably read,...more...
Sam Ruby says: It is Rails, not Rake, that provides middlewares to a Rails application. For convenience, a rake task is provided which shows you these middlewares.
P3.0
10-Feb-13
B1.0
431
#50898: When I run the command rails generate jquery:install --ui --force I get deprecated You are using Rails 3.1 with the asset pipeline enab...more...
Sam Ruby says: Those instructions were removed in the second printing.
P3.0
26-Feb-13
B2.0
432
#49714: Original code doesn't escape directory white spaces. See suggested change below. namespace :db do desc "Backup the development datab...more...
Sam Ruby says: Good catch. Went with Shellwords.escape instead.
P3.0
18-Aug-12
B1.0
581

#51227: who_boughtrequests should have space in between--Trung Lê

Sam Ruby says: the only occurrence I can find of this sequence of words is on page 176, and on this page there is a line break between the two words.
B1.0
04-Apr-13
B2.0

Stuff To Be Considered in the Next Edition

PDF Paper Description Found in Fixed in
1

#49099: Could the report-erratum url in the pdf footer, be modified to contain the pdf page number?--Brian Maltzan

P2.2
11-Apr-12