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Diffstat (limited to 'railties/guides/source/initialization.textile')
| -rw-r--r-- | railties/guides/source/initialization.textile | 48 |
1 files changed, 24 insertions, 24 deletions
diff --git a/railties/guides/source/initialization.textile b/railties/guides/source/initialization.textile index 8aabc3ae91..5ae9cf0f2b 100644 --- a/railties/guides/source/initialization.textile +++ b/railties/guides/source/initialization.textile @@ -7,7 +7,7 @@ This guide explains the internals of the initialization process in Rails as of R endprologue. -This guide goes through every single file, class and method call that is required to boot up the Ruby on Rails stack for a default Rails 3.1 application, explaining each part in detail a long the way. For this guide, we will be focusing on how the two most common methods (+rails server+ and Passenger) boot a Rails application. +This guide goes through every single file, class and method call that is required to boot up the Ruby on Rails stack for a default Rails 3.1 application, explaining each part in detail along the way. For this guide, we will be focusing on how the two most common methods (+rails server+ and Passenger) boot a Rails application. NOTE: Paths in this guide are relative to Rails or a Rails application unless otherwise specified. @@ -17,7 +17,7 @@ As of Rails 3, +script/server+ has become +rails server+. This was done to centr h4. +bin/rails+ -The actual +rails+ command is kept in _bin/rails_ at the and goes like this: +The actual +rails+ command is kept in _bin/rails_: <ruby> #!/usr/bin/env ruby @@ -31,7 +31,7 @@ rescue LoadError end </ruby> -This file will attempt to load +rails/cli+ and if it cannot find it then add the +railties/lib+ path to the load path (+$:+) and will then try to require it again. +This file will attempt to load +rails/cli+. If it cannot find it then +railties/lib+ is added to the load path (+$:+) before retrying. h4. +railties/lib/rails/cli.rb+ @@ -56,7 +56,7 @@ else end </ruby> -The +rbconfig+ file here is out of Ruby's standard library and provides us with the +RbConfig+ class which contains useful information dependent on how Ruby was compiled. We'll see this in use in +railties/lib/rails/script_rails_loader+. +The +rbconfig+ file from the Ruby standard library provides us with the +RbConfig+ class which contains detailed information about the Ruby environment, including how Ruby was compiled. We can see this in use in +railties/lib/rails/script_rails_loader+. <ruby> require 'pathname' @@ -71,7 +71,7 @@ module Rails end </ruby> -The +rails/script_rails_loader+ file uses +RbConfig::Config+ to gather up the +bin_dir+ and +ruby_install_name+ values for the configuration which will result in a path such as +/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby+, which is the default path on Mac OS X. If you're running Windows the path may be something such as +C:/Ruby192/bin/ruby+. Anyway, the path on your system may be different, but the point of this is that it will point at the known ruby executable location for your install. The +RbConfig::CONFIG["EXEEXT"]+ will suffix this path with ".exe" if the script is running on Windows. This constant is used later on in +exec_script_rails!+. As for the +SCRIPT_RAILS+ constant, we'll see that when we get to the +in_rails_application?+ method. +The +rails/script_rails_loader+ file uses +RbConfig::Config+ to obtain the +bin_dir+ and +ruby_install_name+ values for the configuration which together form the path to the Ruby interpreter. The +RbConfig::CONFIG["EXEEXT"]+ will suffix this path with ".exe" if the script is running on Windows. This constant is used later on in +exec_script_rails!+. As for the +SCRIPT_RAILS+ constant, we'll see that when we get to the +in_rails_application?+ method. Back in +rails/cli+, the next line is this: @@ -79,7 +79,7 @@ Back in +rails/cli+, the next line is this: Rails::ScriptRailsLoader.exec_script_rails! </ruby> -This method is defined in +rails/script_rails_loader+ like this: +This method is defined in +rails/script_rails_loader+: <ruby> def self.exec_script_rails! @@ -96,7 +96,7 @@ rescue SystemCallError end </ruby> -This method will first check if the current working directory (+cwd+) is a Rails application or is a subdirectory of one. The way to determine this is defined in the +in_rails_application?+ method like this: +This method will first check if the current working directory (+cwd+) is a Rails application or a subdirectory of one. This is determined by the +in_rails_application?+ method: <ruby> def self.in_rails_application? @@ -104,7 +104,7 @@ def self.in_rails_application? end </ruby> -The +SCRIPT_RAILS+ constant defined earlier is used here, with +File.exists?+ checking for its presence in the current directory. If this method returns +false+, then +in_rails_application_subdirectory?+ will be used: +The +SCRIPT_RAILS+ constant defined earlier is used here, with +File.exists?+ checking for its presence in the current directory. If this method returns +false+ then +in_rails_application_subdirectory?+ will be used: <ruby> def self.in_rails_application_subdirectory?(path = Pathname.new(Dir.pwd)) @@ -112,17 +112,17 @@ def self.in_rails_application_subdirectory?(path = Pathname.new(Dir.pwd)) end </ruby> -This climbs the directory tree until it reaches a path which contains a +script/rails+ file. If a directory is reached which contains this file then this line will run: +This climbs the directory tree until it reaches a path which contains a +script/rails+ file. If a directory containing this file is reached then this line will run: <ruby> exec RUBY, SCRIPT_RAILS, *ARGV if in_rails_application? </ruby> -This is effectively the same as doing +ruby script/rails [arguments]+. Where +[arguments]+ at this point in time is simply "server". +This is effectively the same as running +ruby script/rails [arguments]+, where +[arguments]+ at this point in time is simply "server". h4. +script/rails+ -This file looks like this: +This file is as follows: <ruby> APP_PATH = File.expand_path('../../config/application', __FILE__) @@ -130,7 +130,7 @@ require File.expand_path('../../config/boot', __FILE__) require 'rails/commands' </ruby> -The +APP_PATH+ constant here will be used later in +rails/commands+. The +config/boot+ file that +script/rails+ references is the +config/boot.rb+ file in our application which is responsible for loading Bundler and setting it up. +The +APP_PATH+ constant will be used later in +rails/commands+. The +config/boot+ file referenced here is the +config/boot.rb+ file in our application which is responsible for loading Bundler and setting it up. h4. +config/boot.rb+ @@ -243,7 +243,7 @@ In this file there are a lot of lines such as this inside the +ActiveSupport+ mo autoload :Inflector </ruby> -Due to the overriding of the +autoload+ method, Ruby will know to look for this file at +activesupport/lib/active_support/inflector.rb+ when the +Inflector+ class is first referenced. +Due to the overriding of the +autoload+ method, Ruby will know how to look for this file at +activesupport/lib/active_support/inflector.rb+ when the +Inflector+ class is first referenced. The +active_support/lib/active_support/version.rb+ that is also required here simply defines an +ActiveSupport::VERSION+ constant which defines a couple of constants inside this module, the main constant of this is +ActiveSupport::VERSION::STRING+ which returns the current version of ActiveSupport. @@ -450,7 +450,7 @@ run YourApp::Application The +Rack::Builder.parse_file+ method here takes the content from this +config.ru+ file and parses it using this code: <ruby> -app = eval "Rack::Builder.new {( " + cfgfile + "\n )}.to_app", +app = eval "Rack::Builder.new {( " <plus> cfgfile <plus> "\n )}.to_app", TOPLEVEL_BINDING, config </ruby> @@ -525,19 +525,19 @@ silence_warnings do end </ruby> -These methods can be used to silence STDERR responses and the +silence_stream+ allows you to also silence other streams. Additionally, this mixin allows you to suppress exceptions and capture streams. For more information see the "Silencing Warnings, Streams, and Exceptions":http://guides.rubyonrails.org/active_support_core_extensions.html#silencing-warnings-streams-and-exceptions section from the Active Support Core Extensions Guide. +These methods can be used to silence STDERR responses and the +silence_stream+ allows you to also silence other streams. Additionally, this mixin allows you to suppress exceptions and capture streams. For more information see the "Silencing Warnings, Streams, and Exceptions":active_support_core_extensions.html#silencing-warnings-streams-and-exceptions section from the Active Support Core Extensions Guide. h4. +active_support/core_ext/logger.rb+ The next file that is required is another Active Support core extension, this time to the +Logger+ class. This begins by defining the +around_[level]+ helpers for the +Logger+ class as well as other methods such as a +datetime_format+ getter and setter for the +formatter+ object tied to a +Logger+ object. -For more information see the "Extensions to Logger":http://guides.rubyonrails.org/active_support_core_extensions.html#extensions-to-logger section from the Active Support Core Extensions Guide. +For more information see the "Extensions to Logger":active_support_core_extensions.html#extensions-to-logger section from the Active Support Core Extensions Guide. h4. +railties/lib/rails/application.rb+ The next file required by +railties/lib/rails.rb+ is +application.rb+. This file defines the +Rails::Application+ constant which the application's class defined in +config/application.rb+ in a standard Rails application depends on. Before the +Rails::Application+ class is defined however, there's some other files that get required first. -The first of these is +active_support/core_ext/hash/reverse_merge+ which can be "read about in the Active Support Core Extensions guide":http://guides.rubyonrails.org/active_support_core_extensions.html#merging under the "Merging" section. +The first of these is +active_support/core_ext/hash/reverse_merge+ which can be "read about in the Active Support Core Extensions guide":active_support_core_extensions.html#merging under the "Merging" section. h4. +active_support/file_update_checker.rb+ @@ -575,7 +575,7 @@ Now that +rails/initializable.rb+ has finished being required from +rails/railti h4. +railties/lib/rails/configuration.rb+ -This file defines the +Rails::Configuration+ module, containing the +MiddlewareStackProxy+ class as well as the +Generators+ class. The +MiddlewareStackProxy+ class is used for managing the middleware stack for an application, which we'll see later on. The +Generators+ class provides the functionality used for configuring what generators an application uses through the "+config.generators+ option":http://guides.rubyonrails.org/configuring.html#configuring-generators. +This file defines the +Rails::Configuration+ module, containing the +MiddlewareStackProxy+ class as well as the +Generators+ class. The +MiddlewareStackProxy+ class is used for managing the middleware stack for an application, which we'll see later on. The +Generators+ class provides the functionality used for configuring what generators an application uses through the "+config.generators+ option":configuring.html#configuring-generators. The first file required in this file is +activesupport/deprecation+. @@ -598,11 +598,11 @@ This file defines the +ActiveSupport::Notifications+ module. Notifications provi The "API documentation":http://api.rubyonrails.org/classes/ActiveSupport/Notifications.html for +ActiveSupport::Notifications+ explains the usage of this module, including the methods that it defines. -The file required in +active_support/notifications.rb+ is +active_support/core_ext/module/delegation+ which is documented in the "Active Support Core Extensions Guide":http://guides.rubyonrails.org/active_support_core_extensions.html#method-delegation. +The file required in +active_support/notifications.rb+ is +active_support/core_ext/module/delegation+ which is documented in the "Active Support Core Extensions Guide":active_support_core_extensions.html#method-delegation. h4. +activesupport/core_ext/array/wrap+ -As this file comprises of a core extension, it is covered exclusively in "the Active Support Core Extensions guide":http://guides.rubyonrails.org/active_support_core_extensions.html#wrapping +As this file comprises of a core extension, it is covered exclusively in "the Active Support Core Extensions guide":active_support_core_extensions.html#wrapping h4. +activesupport/lib/active_support/deprecation/reporting.rb+ @@ -624,7 +624,7 @@ h4. +active_support/ordered_options+ This file is the next file required from +rails/configuration.rb+ is the file that defines +ActiveSupport::OrderedOptions+ which is used for configuration options such as +config.active_support+ and the like. -The next file required is +active_support/core_ext/hash/deep_dup+ which is covered in "Active Support Core Extensions guide":http://guides.rubyonrails.org/active_support_core_extensions.html#deep_dup +The next file required is +active_support/core_ext/hash/deep_dup+ which is covered in "Active Support Core Extensions guide":active_support_core_extensions.html#deep_dup The file that is required next from is +rails/paths+ @@ -682,7 +682,7 @@ When the module from this file (+Rails::Initializable+) is included, it extends h4. +railties/lib/rails/engine.rb+ -The next file required in +rails/engine.rb+ is +active_support/core_ext/module/delegation+ which is documented in the "Active Support Core Extensions Guide":http://guides.rubyonrails.org/active_support_core_extensions.html#method-delegation. +The next file required in +rails/engine.rb+ is +active_support/core_ext/module/delegation+ which is documented in the "Active Support Core Extensions Guide":active_support_core_extensions.html#method-delegation. The next two files after this are Ruby standard library files: +pathname+ and +rbconfig+. The file after these is +rails/engine/railties+. @@ -698,7 +698,7 @@ Once this file has finished loading we jump back to +railties/lib/rails/plugin.r h4. Back to +railties/lib/rails/plugin.rb+ -The next file required in this is a core extension from Active Support called +array/conversions+ which is covered in "this section":http://guides.rubyonrails.org/active_support_core_extensions.html#array-conversions of the Active Support Core Extensions Guide. +The next file required in this is a core extension from Active Support called +array/conversions+ which is covered in "this section":active_support_core_extensions.html#array-conversions of the Active Support Core Extensions Guide. Once that file has finished loading, the +Rails::Plugin+ class is defined. @@ -817,7 +817,7 @@ def initializer(name, opts = {}, &blk) end </ruby> -An initializer can be configured to run before or after another initializer, which we'll see a couple of times throughout this initialization process. Anything that inherits from +Rails::Railtie+ may also make use of the +initializer+ method, something which is covered in the "Configuration guide":[http://ryanbigg.com/guides/configuring.html#rails-railtie-initializer]. +An initializer can be configured to run before or after another initializer, which we'll see a couple of times throughout this initialization process. Anything that inherits from +Rails::Railtie+ may also make use of the +initializer+ method, something which is covered in the "Configuration guide":configuring.html#rails-railtie-initializer. The +Initializer+ class here is defined within the +Rails::Initializable+ module and its +initialize+ method is defined to just set up a couple of variables: |