Merge branch 'master' of github.com:lifo/docrails

12 files changed, 124 insertions, 81 deletions

diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index d5665de561..36819553ee 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -174,7 +174,7 @@ module ActiveModel
       to_a.size
     end
 
-    # Returns true if there are any errors, false if not.
+    # Returns true if no errors are found, false otherwise.
     def empty?
       all? { |k, v| v && v.empty? }
     end
diff --git a/activesupport/lib/active_support/core_ext/hash/slice.rb b/activesupport/lib/active_support/core_ext/hash/slice.rb
index d7fb2da0fb..0484d8e5d8 100644
--- a/activesupport/lib/active_support/core_ext/hash/slice.rb
+++ b/activesupport/lib/active_support/core_ext/hash/slice.rb
@@ -30,6 +30,8 @@ class Hash
     omit
   end
 
+  # Removes and returns the key/value pairs matching the given keys.
+  #   {:a => 1, :b => 2, :c => 3, :d => 4}.extract!(:a, :b) # => {:a => 1, :b => 2}
   def extract!(*keys)
     result = {}
     keys.each {|key| result[key] = delete(key) }
diff --git a/railties/guides/source/3_1_release_notes.textile b/railties/guides/source/3_1_release_notes.textile
index c1585c707e..ba36735a0b 100644
--- a/railties/guides/source/3_1_release_notes.textile
+++ b/railties/guides/source/3_1_release_notes.textile
@@ -81,13 +81,13 @@ h3. Railties
 
 * jQuery and Prototype are no longer vendored and is provided from now on by the jquery-rails and prototype-rails gems.
 
-* The application generator accepts an option -j which can be an arbitrary string. If passed "foo", the gem "foo-rails" is added to the Gemfile, and the application JavaScript manifest requires "foo" and "foo_ujs". Currently only "prototype-rails" and "jquery-rails" exist and provide those files via the asset pipeline.
+* The application generator accepts an option +-j+ which can be an arbitrary string. If passed "foo", the gem "foo-rails" is added to the +Gemfile+, and the application JavaScript manifest requires "foo" and "foo_ujs". Currently only "prototype-rails" and "jquery-rails" exist and provide those files via the asset pipeline.
 
-* Generating an application or a plugin runs +bundle install+ unless --skip-gemfile or --skip-bundle is specified.
+* Generating an application or a plugin runs +bundle install+ unless +--skip-gemfile+ or +--skip-bundle+ is specified.
 
-* The controller and resource generators will now automatically produce asset stubs (this can be turned off with --skip-assets). These stubs will use CoffeeScript and Sass, if those libraries are available.
+* The controller and resource generators will now automatically produce asset stubs (this can be turned off with +--skip-assets+). These stubs will use CoffeeScript and Sass, if those libraries are available.
 
-* Scaffold and app generators use the Ruby 1.9 style hash when running on Ruby 1.9. To generate old style hash, --old-style-hash can be passed.
+* Scaffold and app generators use the Ruby 1.9 style hash when running on Ruby 1.9. To generate old style hash, +--old-style-hash+ can be passed.
 
 * Scaffold controller generator creates format block for JSON instead of XML.
 
@@ -109,15 +109,15 @@ h4. Action Controller
 
 * A warning is given out if the CSRF token authenticity cannot be verified.
 
-* Specify +force_ssl+ in a controller to force the browser to transfer data via HTTPS protocol on that particular controller. To limit to specific actions, :only or :except can be used.
+* Specify +force_ssl+ in a controller to force the browser to transfer data via HTTPS protocol on that particular controller. To limit to specific actions, +:only+ or +:except+ can be used.
 
 * Sensitive query string parameters specified in <tt>config.filter_parameters</tt> will now be filtered out from the request paths in the log.
 
-* URL parameters which return nil for +to_param+ are now removed from the query string.
+* URL parameters which return +nil+ for +to_param+ are now removed from the query string.
 
 * Added <tt>ActionController::ParamsWrapper</tt> to wrap parameters into a nested hash, and will be turned on for JSON request in new applications by default. This can be customized by setting <tt>ActionController::Base.wrap_parameters</tt> in <tt>config/initializer/wrap_parameters.rb</tt>.
 
-* Added <tt>config.action_controller.include_all_helpers</tt>. By default <tt>helper :all</tt> is done in <tt>ActionController::Base</tt>, which includes all the helpers by default. Setting +include_all_helpers+ to false will result in including only application_helper and the helper corresponding to controller (like foo_helper for foo_controller).
+* Added <tt>config.action_controller.include_all_helpers</tt>. By default <tt>helper :all</tt> is done in <tt>ActionController::Base</tt>, which includes all the helpers by default. Setting +include_all_helpers+ to +false+ will result in including only application_helper and the helper corresponding to controller (like foo_helper for foo_controller).
 
 * +url_for+ and named url helpers now accept +:subdomain+ and +:domain+ as options.
 
@@ -166,16 +166,18 @@ end
 
 <ruby>
 class PostsController < ActionController::Base
-  stream :only => :index
+  stream
 end
 </ruby>
 
-Please read the docs at "<tt>ActionController::Streaming</tt>":http://edgeapi.rubyonrails.org/classes/ActionController/Streaming.html for more information.
+You can restrict it to some actions by using +:only+ or +:except+. Please read the docs at "<tt>ActionController::Streaming</tt>":http://edgeapi.rubyonrails.org/classes/ActionController/Streaming.html for more information.
 
 * The redirect route method now also accepts a hash of options which will only change the parts of the url in question, or an object which responds to call, allowing for redirects to be reused.
 
 h4. Action Dispatch
 
+* <tt>config.action_dispatch.x_sendfile_header</tt> now defaults to +nil+ and <tt>config/environments/production.rb</tt> doesn't set any particular value for it. This allows servers to set it through <tt>X-Sendfile-Type</tt>.
+
 * <tt>ActionDispatch::MiddlewareStack</tt> now uses composition over inheritance and is no longer an array.
 
 * Added <tt>ActionDispatch::Request.ignore_accept_header</tt> to ignore accept headers.
@@ -200,7 +202,7 @@ h4. Action View
 
 * +file_field+ automatically adds <tt>:multipart => true</tt> to the enclosing form.
 
-* Added a convenience idiom to generate HTML5 data-* attributes in tag helpers from a :data hash of options:
+* Added a convenience idiom to generate HTML5 data-* attributes in tag helpers from a +:data+ hash of options:
 
 <plain>
 tag("div", :data => {:name => 'Stephen', :city_state => %w(Chicago IL)})
@@ -219,7 +221,7 @@ Keys are dasherized. Values are JSON-encoded, except for strings and symbols.
 
 * The submit form helper does not generate an id "object_name_id" anymore.
 
-* Allows <tt>FormHelper#form_for</tt> to specify the :method as a direct option instead of through the :html hash. <tt>form_for(@post, remote: true, method: :delete)</tt> instead of <tt>form_for(@post, remote: true, html: { method: :delete })</tt>.
+* Allows <tt>FormHelper#form_for</tt> to specify the +:method+ as a direct option instead of through the +:html+ hash. <tt>form_for(==@==post, remote: true, method: :delete)</tt> instead of <tt>form_for(==@==post, remote: true, html: { method: :delete })</tt>.
 
 * Provided <tt>JavaScriptHelper#j()</tt> as an alias for <tt>JavaScriptHelper#escape_javascript()</tt>. This supersedes the <tt>Object#j()</tt> method that the JSON gem adds within templates using the JavaScriptHelper.
 
@@ -250,7 +252,7 @@ user.build_account{ |a| a.credit_limit => 100.0 }
 
 * CSV Fixtures are deprecated and support will be removed in Rails 3.2.0.
 
-* <tt>ActiveRecord#new</tt>, <tt>ActiveRecord#create</tt> and <tt>ActiveRecord#update_attributes</tt> all accept a second hash as an option that allows you to specify which role to consider when assigning attributes. This is built on top of ActiveModel's new mass assignment capabilities:
+* <tt>ActiveRecord#new</tt>, <tt>ActiveRecord#create</tt> and <tt>ActiveRecord#update_attributes</tt> all accept a second hash as an option that allows you to specify which role to consider when assigning attributes. This is built on top of Active Model's new mass assignment capabilities:
 
 <ruby>
 class Post < ActiveRecord::Base
@@ -284,7 +286,7 @@ People.limit(1).offset(1).count # => 'SELECT COUNT(*) FROM people LIMIT 1 OFFSET
 
 * <tt>ActiveRecord::Associations::AssociationProxy</tt> has been split. There is now an +Association+ class (and subclasses) which are responsible for operating on associations, and then a separate, thin wrapper called +CollectionProxy+, which proxies collection associations. This prevents namespace pollution, separates concerns, and will allow further refactorings.
 
-* Singular associations (has_one, belongs_to) no longer have a proxy and simply returns the associated record or nil. This means that you should not use undocumented methods such as bob.mother.create - use bob.create_mother instead.
+* Singular associations (+has_one+, +belongs_to+) no longer have a proxy and simply returns the associated record or +nil+. This means that you should not use undocumented methods such as +bob.mother.create+ - use +bob.create_mother+ instead.
 
 * Support the <tt>:dependent</tt> option on <tt>has_many :through</tt> associations. For historical and practical reasons, +:delete_all+ is the default deletion strategy employed by <tt>association.delete(*records)</tt>, despite the fact that the default strategy is +:nullify+ for regular has_many. Also, this only works at all if the source reflection is a belongs_to. For other situations, you should directly modify the through association.
 
@@ -341,7 +343,7 @@ has_many :things, :conditions => 'foo = #{bar}'          # before
 has_many :things, :conditions => proc { "foo = #{bar}" } # after
 </ruby>
 
-Inside the proc, 'self' is the object which is the owner of the association, unless you are eager loading the association, in which case 'self' is the class which the association is within.
+Inside the proc, +self+ is the object which is the owner of the association, unless you are eager loading the association, in which case +self+ is the class which the association is within.
 
 You can have any "normal" conditions inside the proc, so the following will work too:
 <ruby>
@@ -366,7 +368,9 @@ end
 
 * Calling <tt>ActiveRecord::Base#clone</tt> will result in a shallow copy of the record, including copying the frozen state. No callbacks will be called.
 
-* Calling <tt>ActiveRecord::Base#dup</tt> will duplicate the record, including calling after initialize hooks. Frozen state will not be copied, and all associations will be cleared. A duped record will return true for <tt>new_record?</tt>, have a nil id field, and is saveable.
+* Calling <tt>ActiveRecord::Base#dup</tt> will duplicate the record, including calling after initialize hooks. Frozen state will not be copied, and all associations will be cleared. A duped record will return +true+ for <tt>new_record?</tt>, have a +nil+ id field, and is saveable.
+
+* The query cache now works with prepared statements. No changes in the applications are required.
 
 h3. Active Model
 
@@ -380,6 +384,8 @@ h3. Active Model
 
 * Added support for selectively enabling and disabling observers.
 
+* Alternate <tt>I18n</tt> namespace lookup is no longer supported.
+
 h3. Active Resource
 
 * The default format has been changed to JSON for all requests. If you want to continue to use XML you will need to set <tt>self.format = :xml</tt> in the class. For example,
diff --git a/railties/guides/source/action_mailer_basics.textile b/railties/guides/source/action_mailer_basics.textile
index 5b2212d9cb..0941b06cfe 100644
--- a/railties/guides/source/action_mailer_basics.textile
+++ b/railties/guides/source/action_mailer_basics.textile
@@ -242,11 +242,11 @@ end
 
 h5. Sending Email To Multiple Recipients
 
-It is possible to send email to one or more recipients in one email (for e.g. informing all admins of a new signup) by setting the list of emails to the <tt>:to</tt> key. The <tt>to:</tt> key however expects a string so you have join the list of recipients using a comma.
+It is possible to send email to one or more recipients in one email (for e.g. informing all admins of a new signup) by setting the list of emails to the <tt>:to</tt> key. The list of emails can be an array of email addresses or a single string with the addresses separated by commas.
 
 <ruby>
   class AdminMailer < ActionMailer::Base
-    default :to => Admin.all.map(&:email).join(", "),
+    default :to => Admin.all.map(&:email),
             :from => "notification@example.com"
 
     def new_registration(user)
@@ -256,6 +256,8 @@ It is possible to send email to one or more recipients in one email (for e.g. in
   end
 </ruby>
 
+The same format can be used to set carbon copy (Cc:) and blind carbon copy (Bcc:) recipients, by using the <tt>:cc</tt> and <tt>:bcc</tt> keys respectively.
+
 h5. Sending Email With Name
 
 Sometimes you wish to show the name of the person instead of just their email address when they receive the email. The trick to doing that is
diff --git a/railties/guides/source/active_record_validations_callbacks.textile b/railties/guides/source/active_record_validations_callbacks.textile
index 977e736d25..aba3224ba7 100644
--- a/railties/guides/source/active_record_validations_callbacks.textile
+++ b/railties/guides/source/active_record_validations_callbacks.textile
@@ -751,8 +751,6 @@ class Person < ActiveRecord::Base
 end
 </ruby>
 
-
-
 h4. +errors.clear+
 
 The +clear+ method is used when you intentionally want to clear all the messages in the +errors+ collection. Of course, calling +errors.clear+ upon an invalid object won't actually make it valid: the +errors+ collection will now be empty, but the next time you call +valid?+ or any method that tries to save this object to the database, the validations will run again. If any of the validations fail, the +errors+ collection will be filled again.
@@ -799,6 +797,7 @@ h3. Displaying Validation Errors in the View
 Rails maintains an official plugin that provides helpers to display the error messages of your models in your view templates. You can install it as a plugin or as a Gem.
 
 h4. Installing as a plugin
+
 <shell>
 $ rails plugin install git://github.com/joelmoss/dynamic_form.git
 </shell>
@@ -806,6 +805,7 @@ $ rails plugin install git://github.com/joelmoss/dynamic_form.git
 h4. Installing as a Gem
 
 Add this line in your Gemfile:
+
 <ruby>
 gem "dynamic_form"
 </ruby>
diff --git a/railties/guides/source/active_support_core_extensions.textile b/railties/guides/source/active_support_core_extensions.textile
index 38920c2edb..df863935cf 100644
--- a/railties/guides/source/active_support_core_extensions.textile
+++ b/railties/guides/source/active_support_core_extensions.textile
@@ -2095,6 +2095,30 @@ shape_types = [Circle, Square, Triangle].sample(2)
 
 NOTE: Defined in +active_support/core_ext/array/random_access.rb+.
 
+h4. Adding Elements
+
+h5. +prepend+
+
+This method is an alias of <tt>Array#unshift</tt>.
+
+<ruby>
+%w(a b c d).prepend('e')  # => %w(e a b c d)
+[].prepend(10)            # => [10]
+</ruby>
+
+NOTE: Defined in +active_support/core_ext/array/prepend_and_append.rb+.
+
+h5. +append+
+
+This method is an alias of <tt>Array#<<</tt>.
+
+<ruby>
+%w(a b c d).append('e')  # => %w(a b c d e)
+[].append([1,2])         # => [[1,2]]
+</ruby>
+
+NOTE: Defined in +active_support/core_ext/array/prepend_and_append.rb+.
+
 h4. Options Extraction
 
 When the last argument in a method call is a hash, except perhaps for a +&block+ argument, Ruby allows you to omit the brackets:
@@ -2722,6 +2746,18 @@ hash                   # => {:a => 1}
 
 NOTE: Defined in +active_support/core_ext/hash/slice.rb+.
 
+h4. Extracting
+
+The method +extract!+ removes and returns the key/value pairs matching the given keys.
+
+<ruby>
+hash = {:a => 1, :b => 2}
+rest = hash.extract!(:a) # => {:a => 1}
+hash                     # => {:b => 2}
+</ruby>
+
+NOTE: Defined in +active_support/core_ext/hash/slice.rb+.
+
 h4. Indifferent Access
 
 The method +with_indifferent_access+ returns an +ActiveSupport::HashWithIndifferentAccess+ out of its receiver:
diff --git a/railties/guides/source/asset_pipeline.textile b/railties/guides/source/asset_pipeline.textile
index 8a4d61dc3a..74a9e497f2 100644
--- a/railties/guides/source/asset_pipeline.textile
+++ b/railties/guides/source/asset_pipeline.textile
@@ -1,6 +1,6 @@
 h2. Asset Pipeline
 
-This guide will cover the ideology of the asset pipeline introduced in Rails 3.1.
+This guide covers the ideology of the asset pipeline introduced in Rails 3.1.
 By referring to this guide you will be able to:
 
 * Understand what the asset pipeline is and what it does
@@ -19,7 +19,7 @@ Prior to Rails 3.1 these features were added through third-party Ruby libraries
 
 By having this as a core feature of Rails, all developers can benefit from the power of having their assets pre-processed, compressed and minified by one central library, Sprockets. This is part of Rails' "Fast by default" strategy as outlined by DHH in his 2011 keynote at Railsconf.
 
-In new Rails 3.1 application the asset pipeline is enable by default. It can be disabled in +application.rb+ by putting this line inside the +Application+ class definition:
+In new Rails 3.1 application the asset pipeline is enabled by default. It can be disabled in +application.rb+ by putting this line inside the +Application+ class definition:
 
 <plain>
 config.assets.enabled = false
@@ -30,17 +30,17 @@ It is recommended that you use the defaults for all new apps.
 
 h4. Main Features
 
-The first feature of the pipeline is to concatenate assets. This is important in a production environment, as it reduces the number of requests that a browser needs to make to render a web page. While Rails already has a feature to concatenate these types of asset--by placing +:cache => true+ at the end of tags such as +javascript_include_tag+ and +stylesheet_link_tag+--, many people do not use it.
+The first feature of the pipeline is to concatenate assets. This is important in a production environment, as it reduces the number of requests that a browser must make to render a web page. While Rails already has a feature to concatenate these types of assetsi -- by placing +:cache => true+ at the end of tags such as +javascript_include_tag+ and +stylesheet_link_tag+ -- many people do not use it.
 
-The default behavior in Rails 3.1 and onward is to concatenate all files into one master file each for JS and CSS. However, you can separate files or groups of files if required (see below). In production an MD5 fingerprint is inserted into each filename so that the file is cached by the web browser but can be invalidated if the fingerprint is altered.
+The default behavior in Rails 3.1 and onward is to concatenate all files into one master file each for JS and CSS. However, you can separate files or groups of files if required (see below). In production, an MD5 fingerprint is inserted into each filename so that the file is cached by the web browser but can be invalidated if the fingerprint is altered.
 
-The second feature is to minify or compress. For CSS, this usually involves removing whitespace and comments. For JavaScript, more complex processes can be applied. You can choose from a set of built in options or specify your own.
+The second feature is to minify or compress assets. For CSS, this usually involves removing whitespace and comments. For JavaScript, more complex processes can be applied. You can choose from a set of built in options or specify your own.
 
 The third feature is the ability to code these assets using another language, or language extension. These include SCSS or Sass for CSS, CoffeeScript for JavaScript, and ERB for both.
 
 h4. What is Fingerprinting and Why Should I Care?
 
-Fingerprinting is a technique where the filenames of content that is static or infrequently updated is altered to be unique to the content contained in the file.
+Fingerprinting is a technique whereby the filenames of content that is static or infrequently updated is altered to be unique to the content contained in the file.
 
 When a filename is unique and based on its content, HTTP headers can be set to encourage caches everywhere (at ISPs, in browsers) to keep their own copy of the content. When the content is updated, the fingerprint will change and the remote clients will request the new file. This is generally known as _cachebusting_.
 
@@ -52,7 +52,7 @@ global.css => global-908e25f4bf641868d8683022a5b62f54.css
 
 This is the strategy adopted by the Rails asset pipeline.
 
-Rails old strategy was to append a query string to every asset linked with a built-in helper. In the source the generated code looked like this:
+Rails' old strategy was to append a query string to every asset linked with a built-in helper. In the source the generated code looked like this:
 
 <plain>
 /stylesheets/global.css?1309495796
@@ -73,7 +73,7 @@ This has several disadvantages:
 
 The other problem is that when static assets are deployed with each new release of code, the mtime of *all* these files changes, forcing all remote clients to fetch them again, even when the content of those assets has not changed.
 
-Fingerprinting avoids all these problems by ensuring filenames are consistent based on the content.
+Fingerprinting avoids all these problems by ensuring filenames are consistent based on their content.
 
 More reading:
 
@@ -83,11 +83,11 @@ More reading:
 
 h3. How to Use the Asset Pipeline
 
-In previous versions of Rails, all assets were located in subdirectories of +public+ such as +images+, +javascripts+ and +stylesheets+. With the asset pipeline, the preferred location for these assets is now the +app/assets+ directory. Files in this directory will be served by the Sprockets middleware included in the sprockets gem.
+In previous versions of Rails, all assets were located in subdirectories of +public+ such as +images+, +javascripts+ and +stylesheets+. With the asset pipeline, the preferred location for these assets is now the +app/assets+ directory. Files in this directory are served by the Sprockets middleware included in the sprockets gem.
 
 This is not to say that assets can (or should) no longer be placed in +public+; they still can be and will be served as static files by the application or web server. You would only use +app/assets+ if you wish your files to undergo some pre-processing before they are served.
 
-When a scaffold or controller is generated for the application, Rails will also generate a JavaScript file (or CoffeeScript if the +coffee-script+ gem is in the +Gemfile+) and a Cascading Style Sheet file (or SCSS if +sass-rails+ is in the +Gemfile+) file for that controller.
+When a scaffold or controller is generated for the application, Rails also generates a JavaScript file (or CoffeeScript file if the +coffee-script+ gem is in the +Gemfile+) and a Cascading Style Sheet file (or SCSS file if +sass-rails+ is in the +Gemfile+) for that controller.
 
 For example, if a +ProjectsController+ is generated, there will be a new file at +app/assets/javascripts/projects.js.coffee+ and another at +app/assets/stylesheets/projects.css.scss+. You should put any JavaScript or CSS unique to a controller inside their respective asset files, as these files can then be loaded just for these controllers with lines such as +<%= javascript_include_tag params[:controller] %>+ or +<%= stylesheet_link_tag params[:controller] %>+.
 
@@ -101,13 +101,13 @@ Assets can be placed inside an application in one of three locations: +app/asset
 
 +vendor/assets+ is for assets that are owned by outside entities, such as code for JavaScript plugins.
 
-All subdirectories that exist within these three locations will be added to the search path for Sprockets (visible by calling +Rails.application.config.assets.paths+ in a console). When an asset is requested, these paths will be looked through to see if they contain an asset matching the name specified. Once an asset has been found, it's processed by Sprockets and served.
+All subdirectories that exist within these three locations are added to the search path for Sprockets (visible by calling +Rails.application.config.assets.paths+ in a console). When an asset is requested, these paths are looked through to see if they contain an asset matching the name specified. Once an asset has been found, it's processed by Sprockets and served.
 
 h4. Coding Links to Assets
 
-To access assets, we can use the same tags that we are generally familiar with:
+To access assets, you use the same tags that you are generally familiar with:
 
-Sprockets does not add any new methods to require your assets, we still use the familiar +javascript_include_tag+ and +stylesheet_link_tag+.
+Sprockets does not add any new methods to require your assets, you still use the familiar +javascript_include_tag+ and +stylesheet_link_tag+.
 
 <erb>
 <%= stylesheet_link_tag "application" %>
@@ -126,29 +126,29 @@ Images can be organized into directories if required, and they can be accessed b
 <%= image_tag "icons/rails.png" %>
 </erb>
 
-Providing that assets are enabled within our application (+config.assets.enabled+ in the current environment's file is not set to +false+), this file will be served by Sprockets unless a file at +public/assets/rails.png+ exists, in which case that file will be served.
+Providing that assets are enabled within your application (+config.assets.enabled+ in the current environment's file is not set to +false+), this file is served by Sprockets unless a file at +public/assets/rails.png+ exists, in which case that file is served.
 
-Alternatively, a file with an MD5 hash after its name such as +public/assets/rails-af27b6a414e6da00003503148be9b409.png+ will also be picked up by Sprockets. How these hashes are generated is covered in the "Production Assets":#production_assets section later on in this guide.
+Alternatively, a file with an MD5 hash after its name such as +public/assets/rails-af27b6a414e6da00003503148be9b409.png+ is also picked up by Sprockets. How these hashes are generated is covered in the "Production Assets":#production_assets section later on in this guide.
 
-Otherwise, Sprockets will look through the available paths until it finds a file that matches the name and then will serve it, first looking in the application's assets directories and then falling back to the various engines of the application.
+Otherwise, Sprockets looks through the available paths until it finds a file that matches the name and then serves it, first looking in the application's assets directories and then falling back to the various engines of the application.
 
-If you want to use a "css data URI":http://en.wikipedia.org/wiki/Data_URI_scheme - a method of embedding the image data directly into the CSS file - you can use the +asset_data_uri+ helper.
+If you want to use a "css data URI":http://en.wikipedia.org/wiki/Data_URI_scheme -- a method of embedding the image data directly into the CSS file -- you can use the +asset_data_uri+ helper.
 
 <plain>
 #logo { background: url(<%= asset_data_uri 'logo.png' %>)
 </plain>
 
-This will insert a correctly formatted data URI into the CSS source.
+This inserts a correctly-formatted data URI into the CSS source.
 
 h5. CSS and ERB
 
-If you add an +erb+ extension to a CSS asset, making it something such as +application.css.erb+ then you can use the +asset_path+ helper in your CSS rules:
+If you add an +erb+ extension to a CSS asset, making it something such as +application.css.erb+, then you can use the +asset_path+ helper in your CSS rules:
 
 <plain>
 .class{background-image:<%= asset_path 'image.png' %>}
 </plain>
 
-This will write the path to the particular asset being referenced. In this example, it would make sense to have an image in one of the asset load paths, such as +app/assets/images/image.png+, which would be referenced here. If this image is already available in +public/assets+ as a fingerprinted file then that path will be referenced.
+This writes the path to the particular asset being referenced. In this example, it would make sense to have an image in one of the asset load paths, such as +app/assets/images/image.png+, which would be referenced here. If this image is already available in +public/assets+ as a fingerprinted file, then that path is referenced.
 
 Note that the closing tag cannot be of the style +-%>+.
 
@@ -166,7 +166,7 @@ The more generic form can also be used but the asset path and class must both be
 
 h4. Manifest Files and Directives
 
-Sprockets uses manifest files to determine which assets to include and serve. These manifest files contain _directives_ - instructions that tell Sprockets which files to require in order to build a single CSS or JavaScript file. With these directives, Sprockets will load the files specified, process them if necessary, concatenate them into one single file and then compress them (if +Rails.application.config.assets.compress+ is set to +true+). By serving one file rather than many, a page's load time is greatly reduced as there is not as many requests to make for each file.
+Sprockets uses manifest files to determine which assets to include and serve. These manifest files contain _directives_ -- instructions that tell Sprockets which files to require in order to build a single CSS or JavaScript file. With these directives, Sprockets loads the files specified, processes them if necessary, concatenates them into one single file and then compresses them (if +Rails.application.config.assets.compress+ is set to +true+). By serving one file rather than many, the load time of pages are greatly reduced as there are fewer requests to make.
 
 For example, in the default Rails application there's a +app/assets/javascripts/application.js+ file which contains the following lines:
 
@@ -176,9 +176,11 @@ For example, in the default Rails application there's a +app/assets/javascripts/
 //= require_tree .
 </plain>
 
-In JavaScript files, directives begin with +//=+. In this case, the following file is using the +require+ directive and the +require_tree+ directive. The +require+ directive tells Sprockets that we would like to require a file called +jquery.js+ that is available somewhere in the search path for Sprockets. By default, this is located inside the +vendor/assets/javascripts+ directory contained within the +jquery-rails+ gem. An identical event takes place for the +jquery_ujs+ require
+In JavaScript files, the directives begin with +//=+. In this case, the file is using the +require+ and the +require_tree+ directives. The +require+ directive is used to tell Sprockets the files that you wish to require. Here, you are requiring the files +jquery.js+ and +jquery_ujs.js+ that are available somewhere in the search path for Sprockets. You need not supply the extensions explicitly. Sprockets assumes you are requiring a +.js+ file when done from within a +.js+ file.
 
-The +require_tree .+ directive tells Sprockets to include _all_ JavaScript files in this directory into the output. Only a path relative to the file can be specified.
+NOTE. In Rails 3.1, the +jquery.js+ and +jquery_ujs.js+ files are located inside the +vendor/assets/javascripts+ directory contained within the +jquery-rails+ gem.
+
+The +require_tree .+ directive tells Sprockets to include _all_ JavaScript files in this directory into the output. Only a path relative to the file can be specified. There is also a +require_directory+ directive which includes all JavaScript files only in the directory specified (no nesting).
 
 There's also a default +app/assets/stylesheets/application.css+ file which contains these lines:
 
@@ -189,13 +191,13 @@ There's also a default +app/assets/stylesheets/application.css+ file which conta
 */
 </plain>
 
-The directives that work in the JavaScript files will also work in stylesheets, obviously including stylesheets rather than JavaScript files. The +require_tree+ directive here works the same way as the JavaScript one, requiring all stylesheets from the current directory.
+The directives that work in the JavaScript files also work in stylesheets, obviously including stylesheets rather than JavaScript files. The +require_tree+ directive here works the same way as the JavaScript one, requiring all stylesheets from the current directory.
 
-In this example +require_self+ is used. This will put the CSS contained within the file (if any) at the top of any other CSS in this file unless +require_self+ is specified after another +require+ directive.
+In this example +require_self+ is used. This puts the CSS contained within the file (if any) at the top of any other CSS in this file unless +require_self+ is specified after another +require+ directive.
 
 You can have as many manifest files as you need. For example the +admin.css+ and +admin.js+ manifest could contain the JS and CSS files that are used for the admin section of an application.
 
-For some assets (like CSS) the compiled order is important. You can specify individual files and they will be compiled in the order specified:
+For some assets (like CSS) the compiled order is important. You can specify individual files and they are compiled in the order specified:
 
 <plain>
 /* ...
@@ -208,36 +210,36 @@ For some assets (like CSS) the compiled order is important. You can specify indi
 
 h4. Preprocessing
 
-The file extensions used on an asset will determine what preprocessing will be applied. When a controller or a scaffold is generated with the default Rails gemset, a CoffeeScript file and a SCSS file will be generated in place of a regular JavaScript and CSS file. The example used before was a controller called "projects", which generated an +app/assets/javascripts/projects.js.coffee+ and a +app/assets/stylesheets/projects.css.scss+ file.
+The file extensions used on an asset determine what preprocessing is applied. When a controller or a scaffold is generated with the default Rails gemset, a CoffeeScript file and a SCSS file are generated in place of a regular JavaScript and CSS file. The example used before was a controller called "projects", which generated an +app/assets/javascripts/projects.js.coffee+ and a +app/assets/stylesheets/projects.css.scss+ file.
 
-When these files are requested, they will be processed by the processors provided by the +coffee-script+ and +sass-rails+ gems and then sent back to the browser as JavaScript and CSS respectively.
+When these files are requested, they are processed by the processors provided by the +coffee-script+ and +sass-rails+ gems and then sent back to the browser as JavaScript and CSS respectively.
 
-Additional layers of pre-processing can be requested by adding other extensions, where each extension will be processed in a right-to-left manner. These should be used in the order the processing should be applied. For example, a stylesheet called +app/assets/stylesheets/projects.css.scss.erb+ would first be processed as ERB, then SCSS and finally served as CSS. The same applies to a JavaScript file - +app/assets/javascripts/projects.js.coffee.erb+ would be process as ERB, CoffeeScript and served as JavaScript.
+Additional layers of pre-processing can be requested by adding other extensions, where each extension is processed in a right-to-left manner. These should be used in the order the processing should be applied. For example, a stylesheet called +app/assets/stylesheets/projects.css.scss.erb+ is first processed as ERB, then SCSS and finally served as CSS. The same applies to a JavaScript file -- +app/assets/javascripts/projects.js.coffee.erb+ is processed as ERB, CoffeeScript and served as JavaScript.
 
-Keep in mind that the order of these pre-processors is important. For example, if we called our JavaScript file +app/assets/javascripts/projects.js.erb.coffee+ then it would be processed with the CoffeeScript interpreter first, which wouldn't understand ERB and therefore we would run into problems.
+Keep in mind that the order of these pre-processors is important. For example, if you called your JavaScript file +app/assets/javascripts/projects.js.erb.coffee+ then it is processed with the CoffeeScript interpreter first, which wouldn't understand ERB and therefore you would run into problems.
 
 h3. In Development
 
 In the development environment assets are compiled and cached on the first request after the server is started. Sprockets sets a +must-validate+ Cache-Control HTTP header to reduce request overhead on subsequent requests - on these the browser gets a 304 (not-modified) response.
 
-If any of the files in the manifest have changed between requests, the server will respond with a new compiled file.
+If any of the files in the manifest have changed between requests, the server responds with a new compiled file.
 
 h4. Debugging Assets
 
-You can put +?debug_assets=true+ or +?debug_assets=1+ at the end of a URL and Sprockets will expand the lines which load the assets. For example, if we had an +app/assets/javascripts/application.js+ file containing these lines:
+You can put +?debug_assets=true+ or +?debug_assets=1+ at the end of a URL and Sprockets expands the lines which load the assets. For example, if you had an +app/assets/javascripts/application.js+ file containing these lines:
 
 <plain>
 //= require "projects"
 //= require "tickets"
 </plain>
 
-By default, this would only render this line when used with +<%= javascript_include_tag "application" %>+ in a view or layout:
+By default, this only renders this line when used with +<%= javascript_include_tag "application" %>+ in a view or layout:
 
 <html>
 <script src='/assets/application.js'></script>
 </html>
 
-When the +debug_assets+ parameter is set, this line will be expanded out into three separate lines, separating out the combined file into their parts.
+When the +debug_assets+ parameter is set, this line is expanded out into three separate lines, separating out the combined file into their parts.
 
 <html>
 <script src='/assets/application.js'></script>
@@ -251,7 +253,7 @@ h3. In Production
 
 In the production environment, assets are served slightly differently.
 
-On the first request the assets are compiled and cached as described above, however the manifest names are altered to include an MD5 hash. Files names typically will look like these:
+On the first request the assets are compiled and cached as described above, however the manifest names are altered to include an MD5 hash. Files names typically look like these:
 
 <plain>
 /assets/application-908e25f4bf641868d8683022a5b62f54.js
@@ -268,7 +270,7 @@ h4. Precompiling Assets
 
 Even though assets are served by Rack::Cache with far-future headers, in high traffic sites this may not be fast enough.
 
-Rails comes bundled with a rake task to compile the manifests to files on disc. These are located in the +public/assets+ directory where they will be served by your web server instead of the Rails application.
+Rails comes bundled with a rake task to compile the manifests to files on disc. These are located in the +public/assets+ directory where they are served by your web server instead of the Rails application.
 
 The rake task is:
 
@@ -276,7 +278,7 @@ The rake task is:
 rake assets:precompile
 </plain>
 
-Capistrano (v2.8.0+) has a recipe to to handle this in deployment. Add the following line to +Capfile+:
+Capistrano (v2.8.0+) has a recipe to handle this in deployment. Add the following line to +Capfile+:
 
 <erb>
 load 'deploy/assets'
@@ -284,9 +286,9 @@ load 'deploy/assets'
 
 This links the folder specified in +config.assets.prefix+ to +shared/assets+. If you already use this folder you'll need to write your own deployment task.
 
-It is important for this folder is shared between deployments so that remotely cached pages that reference the old compiled assets still work for the life of the cached page.
+It is important that this folder is shared between deployments so that remotely cached pages that reference the old compiled assets still work for the life of the cached page.
 
-The default matcher for compiling files will include +application.js+, +application.css+ and all files that do not end in +js+ or +css+:
+The default matcher for compiling files includes +application.js+, +application.css+ and all files that do not end in +js+ or +css+:
 
 <ruby>
 [ /\w+\.(?!js|css).+/, /application.(css|js)$/ ]
@@ -318,7 +320,7 @@ For Apache:
 
 TODO: NGINX instructions
 
-When files are precompiled Sprockets also creates "Gzip":http://en.wikipedia.org/wiki/Gzip (.gz) version of your assets. This avoids the server having to do this for any requests; it can simply read the compressed files from disc. You must configure your server to use gzip compression and serve the compressed assets that will be stored in the public/assets folder. The following configuration options can be used:
+When files are precompiled, Sprockets also creates a "Gzip":http://en.wikipedia.org/wiki/Gzip (.gz) version of your assets. This avoids the server having to do this for any requests; it can simply read the compressed files from disc. You must configure your server to use gzip compression and serve the compressed assets that will be stored in the public/assets folder. The following configuration options can be used:
 
 TODO: Apache instructions
 
@@ -330,7 +332,7 @@ h4. CSS Compression
 
 There is currently one option for compressing CSS - YUI. This Gem extends the CSS syntax and offers minification.
 
-The following line will enable YUI compression, and requires the +yui-compressor+ gem.
+The following line enables YUI compression, and requires the +yui-compressor+ gem.
 
 <erb>
 config.assets.css_compressor = :yui
@@ -342,19 +344,19 @@ h4. JavaScript
 
 Possible options for JavaScript compression are +:closure+, +:uglifier+ and +:yui+. These require the use of the +closure-compiler+, +uglifier+ or +yui-compressor+ gems respectively.
 
-The default Gemfile includes "uglifier":https://github.com/lautis/uglifier. This gem wraps "UglifierJS":https://github.com/mishoo/UglifyJS (written for NodeJS) in Ruby. It compress your code by removing white spaces and other magical things like changing your +if+ and +else+ statements to ternary operators where possible.
+The default Gemfile includes "uglifier":https://github.com/lautis/uglifier. This gem wraps "UglifierJS":https://github.com/mishoo/UglifyJS (written for NodeJS) in Ruby. It compresses your code by removing white space and other magical things like changing your +if+ and +else+ statements to ternary operators where possible.
 
-The following line will invoke uglifier for JavaScript compression.
+The following line invokes +uglifier+ for JavaScript compression.
 
 <erb>
-config.assets.js_compressor  = :uglifier
+config.assets.js_compressor = :uglifier
 </erb>
 
 The +config.assets.compress+ must be set to +true+ to enable JavaScript compression
 
 h4. Using Your Own Compressor
 
-The compressor config settings for CSS and JavaScript will also take any Object. This object must have a +compress+ method that takes a string as the sole argument and it must return a string.
+The compressor config settings for CSS and JavaScript also take any Object. This object must have a +compress+ method that takes a string as the sole argument and it must return a string.
 
 <erb>
 class Transformer
@@ -364,7 +366,7 @@ class Transformer
 end
 </erb>
 
-To enable this pass a +new+ Object to the config option in +application.rb+:
+To enable this, pass a +new+ Object to the config option in +application.rb+:
 
 <erb>
 config.assets.css_compressor = Transformer.new
@@ -385,7 +387,7 @@ This is a handy option if you have any existing project (pre Rails 3.1) that alr
 
 h4. X-Sendfile Headers
 
-The X-Sendfile header is a directive to the server to ignore the response from the application, and instead serve the file specified in the headers. This option is off be default, but can be enabled if your server supports it. When enabled, this passes responsibility for serving the file to the web server, which is faster.
+The X-Sendfile header is a directive to the server to ignore the response from the application, and instead serve the file specified in the headers. This option is off by default, but can be enabled if your server supports it. When enabled, this passes responsibility for serving the file to the web server, which is faster.
 
 Apache and nginx support this option which is enabled in <tt>config/environments/production.rb</tt>.
 
diff --git a/railties/guides/source/configuring.textile b/railties/guides/source/configuring.textile
index 2ff5de2334..110c04f66e 100644
--- a/railties/guides/source/configuring.textile
+++ b/railties/guides/source/configuring.textile
@@ -557,7 +557,7 @@ The error occurred while evaluating nil.each
 
 *+set_load_path+* This initializer runs before +bootstrap_hook+. Adds the +vendor+, +lib+, all directories of +app+ and any paths specified by +config.load_paths+ to +$LOAD_PATH+.
 
-*+set_autoload_path+* This initializer runs before +bootstrap_hook+. Adds all sub-directories of +app+ and paths specified by +config.autoload_paths+ to +ActiveSupport::Dependencies.autoload_paths+.
+*+set_autoload_paths+* This initializer runs before +bootstrap_hook+. Adds all sub-directories of +app+ and paths specified by +config.autoload_paths+ to +ActiveSupport::Dependencies.autoload_paths+.
 
 *+add_routing_paths+* Loads (by default) all +config/routes.rb+ files (in the application and railties, including engines) and sets up the routes for the application.
 
diff --git a/railties/guides/source/initialization.textile b/railties/guides/source/initialization.textile
index 154df51cdc..49d7513448 100644
--- a/railties/guides/source/initialization.textile
+++ b/railties/guides/source/initialization.textile
@@ -190,7 +190,8 @@ aliases = {
   "g"  => "generate",
   "c"  => "console",
   "s"  => "server",
-  "db" => "dbconsole"
+  "db" => "dbconsole",
+  "r"  => "runner"
 }
 
 command = ARGV.shift
diff --git a/railties/guides/source/layouts_and_rendering.textile b/railties/guides/source/layouts_and_rendering.textile
index 57485e8986..87ba8ab82d 100644
--- a/railties/guides/source/layouts_and_rendering.textile
+++ b/railties/guides/source/layouts_and_rendering.textile
@@ -1179,14 +1179,14 @@ On pages generated by +NewsController+, you want to hide the top menu and add a
 <% end %>
 <% content_for :content do %>
   <div id="right_menu">Right menu items here</div>
-  <%= yield(:news_content) or yield %>
+  <%= content_for?(:news_content) ? yield(:news_content) : yield %>
 <% end %>
 <%= render :template => 'layouts/application' %>
 </erb>
 
 That's it. The News views will use the new layout, hiding the top menu and adding a new right menu inside the "content" div.
 
-There are several ways of getting similar results with different sub-templating schemes using this technique. Note that there is no limit in nesting levels. One can use the +ActionView::render+ method via +render :template => 'layouts/news'+ to base a new layout on the News layout. If you are sure you will not subtemplate the +News+ layout, you can replace the +yield(:news_content) or yield+ with simply +yield+.
+There are several ways of getting similar results with different sub-templating schemes using this technique. Note that there is no limit in nesting levels. One can use the +ActionView::render+ method via +render :template => 'layouts/news'+ to base a new layout on the News layout. If you are sure you will not subtemplate the +News+ layout, you can replace the +content_for?(:news_content) ? yield(:news_content) : yield+ with simply +yield+.
 
 h3. Changelog
 
diff --git a/railties/guides/source/migrations.textile b/railties/guides/source/migrations.textile
index 4476e067a6..9da12e2e18 100644
--- a/railties/guides/source/migrations.textile
+++ b/railties/guides/source/migrations.textile
@@ -471,8 +471,8 @@ By default migrations tell you exactly what they're doing and how long it took.
 
 Several methods are provided that allow you to control all this:
 
-* +suppress_messages+ suppresses any output generated by its block
-* +say+ outputs text (the second argument controls whether it is indented or not)
+* +suppress_messages+ takes a block as an argument and suppresses any output generated by the block.
+* +say+ takes a message argument and outputs it as is. A second boolean argument can be passed to specify whether to indent or not.
 * +say_with_time+ outputs text along with how long it took to run its block. If the block returns an integer it assumes it is the number of rows affected.
 
 For example, this migration
@@ -510,7 +510,7 @@ generates the following output
 20080906170109 CreateProducts: migrated (10.0097s)
 </shell>
 
-If you just want Active Record to shut up then running +rake db:migrate VERBOSE=false+ will suppress any output.
+If you just want Active Record to shut up then running +rake db:migrate VERBOSE=false+ will suppress all output.
 
 h3. Using Models in Your Migrations
 
diff --git a/railties/guides/source/rails_application_templates.textile b/railties/guides/source/rails_application_templates.textile
index 90fc763349..566f8a0bdd 100644
--- a/railties/guides/source/rails_application_templates.textile
+++ b/railties/guides/source/rails_application_templates.textile
@@ -148,7 +148,7 @@ The above creates +lib/tasks/bootstrap.rake+ with a +boot:strap+ rake task.
 
 h4. generate(what, args)
 
-Runs the supplied rails generator with given arguments. For example, I love to scaffold some whenever I’m playing with Rails:
+Runs the supplied rails generator with given arguments.
 
 <ruby>
 generate(:scaffold, "person", "name:string", "address:text", "age:number")
@@ -176,12 +176,6 @@ You can also run rake tasks with a different Rails environment:
 rake "db:migrate", :env => 'production'
 </ruby>
 
-Or even use sudo:
-
-<ruby>
-rake "gems:install", :sudo => true
-</ruby>
-
 h4. route(routing_code)
 
 This adds a routing entry to the +config/routes.rb+ file. In above steps, we generated a person scaffold and also removed +public/index.html+. Now to make +PeopleController#index+ as the default page for the application: