@@ -571,7 +571,7 @@ NOTE: Defined in +active_support/core_ext/module/attr_accessor_with_default.rb+.
h5. Internal Attributes
When you are defining an attribute in a class that is meant to be subclassed name collisions are a risk. That's remarkably important for libraries.
When you are defining an attribute in a class that is meant to be subclassed, name collisions are a risk. That's remarkably important for libraries.
Active Support defines the macros +attr_internal_reader+, +attr_internal_writer+, and +attr_internal_accessor+. They behave like their Ruby built-in +attr_*+ counterparts, except they name the underlying instance variable in a way that makes collisions less likely.
* +config.active_record.whitelist_attributes+ will create an empty whitelist of attributes available for mass-assignment security for all models in your app.
* +config.active_record.identity_map+ controls whether the identity map is enabled, and is false by default.
The MySQL adapter adds one additional configuration option:
* +ActiveRecord::ConnectionAdapters::MysqlAdapter.emulate_booleans+ controls whether Active Record will consider all +tinyint(1)+ columns in a MySQL database to be booleans and is true by default.
@@ -450,6 +450,8 @@ start a web server on your development machine. You can do this by running:
$ rails server
</shell>
TIP: Compiling CoffeeScript to JavaScript requires a JavaScript runtime and the absence of a runtime will give you an +execjs+ error. Usually Mac OS X and Windows come with a JavaScript runtime installed. +therubyracer+ and +therubyrhino+ are the commonly used runtimes for Ruby and JRuby respectively. You can also investigate a list of runtimes at "ExecJS":https://github.com/sstephenson/execjs.
This will fire up an instance of the WEBrick web server by default (Rails can
also use several other web servers). To see your application in action, open a
browser window and navigate to "http://localhost:3000":http://localhost:3000.
@@ -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:
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:
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".
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.
