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Diffstat (limited to 'railties/guides/source/initialization.textile')
-rw-r--r-- | railties/guides/source/initialization.textile | 78 |
1 files changed, 29 insertions, 49 deletions
diff --git a/railties/guides/source/initialization.textile b/railties/guides/source/initialization.textile index e458413b35..9a0e23385d 100644 --- a/railties/guides/source/initialization.textile +++ b/railties/guides/source/initialization.textile @@ -11,7 +11,7 @@ This guide first describes the process of +rails server+ then explains the Passe h3. Launch! -As of Rails 3, +script/server+ has become +rails server+. This was done to centralise all rails related commands to one common file. +As of Rails 3, +script/server+ has become +rails server+. This was done to centralize all rails related commands to one common file. The actual +rails+ command is kept in _railties/bin/rails_ and goes like this: @@ -58,11 +58,8 @@ In +script/rails+ we see the following: #!/usr/bin/env ruby # This command will automatically be run when you run "rails" with Rails 3 gems installed from the root of your application. - ENV_PATH = File.expand_path('../../config/environment', __FILE__) - BOOT_PATH = File.expand_path('../../config/boot', __FILE__) - APP_PATH = File.expand_path('../../config/application', __FILE__) - - require BOOT_PATH + APP_PATH = File.expand_path('../../config/application', __FILE__) + require File.expand_path('../../config/boot', __FILE__) require 'rails/commands' </ruby> @@ -79,15 +76,19 @@ h3. _config/boot.rb_ _config/boot.rb_ is the first stop for everything for initializing your application. This boot process does quite a bit of work for you and so this section attempts to go in-depth enough to explain what each of the pieces does. <ruby> - # Use Bundler (preferred) + require 'rubygems' + + # Set up gems listed in the Gemfile. + gemfile = File.expand_path('../../Gemfile', __FILE__) begin - require File.expand_path('../../.bundle/environment', __FILE__) - rescue LoadError - require 'rubygems' + ENV['BUNDLE_GEMFILE'] = gemfile require 'bundler' Bundler.setup - end - + rescue Bundler::GemNotFound => e + STDERR.puts e.message + STDERR.puts "Try running `bundle install`." + exit! + end if File.exist?(gemfile) </ruby> h3. Bundled Rails (3.x) @@ -140,8 +141,8 @@ Here the only two gems we need are +rails+ and +sqlite3-ruby+, so it seems. This * activesupport-3.0.0.beta4.gem * arel-0.4.0.gem * builder-2.1.2.gem -* bundler-0.9.26.gem -* erubis-2.6.5.gem +* bundler-1.0.0.beta.2.gem +* erubis-2.6.6.gem * i18n-0.4.1.gem * mail-2.2.4.gem * memcache-client-1.8.3.gem @@ -156,7 +157,7 @@ Here the only two gems we need are +rails+ and +sqlite3-ruby+, so it seems. This * sqlite3-ruby-1.3.0.gem * text-format-1.0.0.gem * text-hyphen-1.0.0.gem -* thor-0.13.6.gem +* thor-0.13.7.gem * treetop-1.4.8.gem * tzinfo-0.3.22.gem @@ -164,33 +165,7 @@ TODO: Prettify when it becomes more stable. I won't go into what each of these gems are, as that is really something that needs covering on a case-by-case basis. We will however just dig a little under the surface of Bundler. -Back in _config/boot.rb_, the first line will try to include _.bundle/environment.rb_, which doesn't exist in a bare-bones Rails application and because this file does not exist Ruby will raise a +LoadError+ which will be rescued and run the following code: - -<ruby> - require 'rubygems' - require 'bundler' - Bundler.setup -</ruby> - -+Bundler.setup+ here will load and parse the +Gemfile+ and add the _lib_ directory of the gems mentioned **and** their dependencies (**and** their dependencies' dependencies, and so on) to the +$LOAD_PATH+. - -Now we will go down the alternate timeline where we generate a _.bundle/environment.rb_ file using the +bundle lock+ command. This command also creates a _Gemfile.lock_ file which is actually a YAML file loaded by this method in Bundler before it moves on to check for _Gemfile_: - -<ruby> - def definition(gemfile = default_gemfile) - configure - root = Pathname.new(gemfile).dirname - lockfile = root.join("Gemfile.lock") - if lockfile.exist? - Definition.from_lock(lockfile) - else - Definition.from_gemfile(gemfile) - end - end -</ruby> - - -The _.bundle/environment.rb_ file adds the _lib_ directory of all the gems specified in +Gemfile.lock+ to +$LOAD_PATH+. +Back in _config/boot.rb_, we call +Bundler.setup+ which will load and parse the +Gemfile+ and add the _lib_ directory of the gems mentioned **and** their dependencies (**and** their dependencies' dependencies, and so on) to the +$LOAD_PATH+. h3. Requiring Rails @@ -326,6 +301,11 @@ As you can see for the duration of the +eager_autoload+ block the class variable module ActiveSupport extend ActiveSupport::Autoload + autoload :DescendantsTracker + autoload :FileUpdateChecker + autoload :LogSubscriber + autoload :Notifications + # TODO: Narrow this list down eager_autoload do autoload :BacktraceCleaner @@ -348,7 +328,6 @@ As you can see for the duration of the +eager_autoload+ block the class variable autoload :OptionMerger autoload :OrderedHash autoload :OrderedOptions - autoload :Notifications autoload :Rescuable autoload :SecureRandom autoload :StringInquirer @@ -589,19 +568,20 @@ This file (_railties/lib/rails.rb_) requires the very, very basics that Rails ne require 'action_dispatch/railtie' </ruby> -+require 'pathname'+ requires the Pathname class which is used for returning a Pathname object for +Rails.root+ so that instead of doing: ++require 'pathname'+ requires the Pathname class which is used for returning a Pathname object for +Rails.root+. Although is coming to use this path name to generate paths as below: <ruby> - File.join(Rails.root, "app/controllers") + Rails.root.join("app/controllers") </ruby> -You may do: +Pathname can also be converted to string, so the following syntax is preferred: <ruby> - Rails.root.join("app/controllers") + "#{Rails.root}/app/controllers" </ruby> -Although this is not new to Rails 3 (it was available in 2.3.5), it is something worthwhile pointing out. + +This works because Ruby automatically handles file path conversions. Although this is not new to Rails 3 (it was available in 2.3.5), it is something worthwhile pointing out. Inside this file there are other helpful helper methods defined, such as +Rails.root+, +Rails.env+, +Rails.logger+ and +Rails.application+. @@ -1833,7 +1813,7 @@ We do not already have a +Rails.application+, so instead this resorts to calling end </ruby> -This +called_from+ setting looks a little overwhelming to begin with, but the short end of it is that it returns the route to your application's config directory, something like: _/home/you/yourapp/config_. After +called_from+ has been set, +super+ is again called and this means the +Rails::Railtie#inherited+ method (in _railties/lib/rails/railtie.rb_): +This +called_from+ setting looks a little overwhelming to begin with, but the short end of it is that it returns your application's root, something like: _/home/you/yourapp_. After +called_from+ has been set, +super+ is again called and this means the +Rails::Railtie#inherited+ method (in _railties/lib/rails/railtie.rb_): <ruby> def inherited(base) |