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| -rw-r--r-- | guides/source/initialization.md | 29 |
1 files changed, 21 insertions, 8 deletions
diff --git a/guides/source/initialization.md b/guides/source/initialization.md index 738591659d..11c736585f 100644 --- a/guides/source/initialization.md +++ b/guides/source/initialization.md @@ -7,14 +7,17 @@ as of Rails 4. It is an extremely in-depth guide and recommended for advanced Ra After reading this guide, you will know: * How to use `rails server`. +* The timeline of Rails' initialization sequence. +* Where different files are required by the boot sequence. +* How the Rails::Server interface is defined and used. -------------------------------------------------------------------------------- This guide goes through every method call that is required to boot up the Ruby on Rails stack for a default Rails 4 application, explaining each part in detail along the way. For this -guide, we will be focusing on what happens when you execute +rails -server+ to boot your app. +guide, we will be focusing on what happens when you execute `rails server` +to boot your app. NOTE: Paths in this guide are relative to Rails or a Rails application unless otherwise specified. @@ -26,7 +29,7 @@ quickly. Launch! ------- -Now we finally boot and initialize the app. It all starts with your app's +Let's start to boot and initialize the app. It all begins with your app's `bin/rails` executable. A Rails application is usually started by running `rails console` or `rails server`. @@ -57,7 +60,8 @@ require 'bundler/setup' if File.exists?(ENV['BUNDLE_GEMFILE']) In a standard Rails application, there's a `Gemfile` which declares all dependencies of the application. `config/boot.rb` sets `ENV['BUNDLE_GEMFILE']` to the location of this file. If the Gemfile -exists, `bundler/setup` is then required. +exists, then `bundler/setup` is required. The require is used by Bundler to +configure the load path for your Gemfile's dependencies. A standard Rails application depends on several gems, specifically: @@ -251,9 +255,9 @@ set earlier) is required. ### `config/application` -When `require APP_PATH` is executed, `config/application.rb` is loaded. -This file exists in your app and it's free for you to change based -on your needs. +When `require APP_PATH` is executed, `config/application.rb` is loaded (recall +that `APP_PATH` is defined in `bin/rails`). This file exists in your application +and it's free for you to change based on your needs. ### `Rails::Server#start` @@ -443,7 +447,9 @@ I18n and Rails configuration are all being defined here. ### Back to `config/environment.rb` -When `config/application.rb` has finished loading Rails, and defined +The rest of `config/application.rb` defines the configuration for the +`Rails::Application` which will be used once the application is fully +initialized. When `config/application.rb` has finished loading Rails and defined the application namespace, we go back to `config/environment.rb`, where the application is initialized. For example, if the application was called `Blog`, here we would find `Blog::Application.initialize!`, which is @@ -471,6 +477,13 @@ traverses all the class ancestors looking for an `initializers` method, sorting them and running them. For example, the `Engine` class will make all the engines available by providing the `initializers` method. +The `Rails::Application` class, as defined in `railties/lib/rails/application.rb` +defines `bootstrap`, `railtie`, and `finisher` initializers. The `bootstrap` initializers +prepare the application (like initializing the logger) while the `finisher` +initializers (like building the middleware stack) are run last. The `railtie` +initializers are the initializers which have been defined on the `Rails::Application` +itself and are run between the `bootstrap` and `finishers`. + After this is done we go back to `Rack::Server` ### Rack: lib/rack/server.rb |