Updated the generators guide.

This commit is contained in:
José Valim 2010-04-30 12:50:42 +02:00
parent cde168edbb
commit 34908e4a66

@ -88,9 +88,7 @@ And it will create a new generator as follow:
<ruby>
class InitializerGenerator < Rails::Generators::NamedBase
def self.source_root
@source_root ||= File.expand_path(File.join(File.dirname(__FILE__), 'templates'))
end
source_root File.expand_path("../templates", __FILE__)
end
</ruby>
@ -115,9 +113,7 @@ And now let's change the generator to copy this template when invoked:
<ruby>
class InitializerGenerator < Rails::Generators::NamedBase
def self.source_root
@source_root ||= File.expand_path(File.join(File.dirname(__FILE__), 'templates'))
end
source_root File.expand_path("../templates", __FILE__)
def copy_initializer_file
copy_file "initializer.rb", "config/initializers/#{file_name}.rb"
@ -135,21 +131,18 @@ We can see that now a initializer named foo was created at +config/initializers/
h3. Generators lookup
Now that we know how to create generators, we must know where Rails looks for generators before invoking them. When we invoke the initializer generator, Rails looks at the following paths in the given order:
With our first generator created, we must discuss briefly generators lookup. The way Rails finds generators is exactly the same way Ruby find files, i.e. using +$LOAD_PATHS+.
For instance, when you say +rails g initializer foo+, rails knows you want to invoke the initializer generator and then search for the following generators in the $LOAD_PATHS:
<shell>
RAILS_APP/lib/generators
RAILS_APP/lib/rails_generators
RAILS_APP/vendor/plugins/*/lib/generators
RAILS_APP/vendor/plugins/*/lib/rails_generators
GEMS_PATH/*/lib/generators
GEMS_PATH/*/lib/rails_generators
~/rails/generators
~/rails/rails_generators
RAILS_GEM/lib/rails/generators
rails/generators/initializer/initializer_generator.rb
generators/initializer/initializer_generator.rb
rails/generators/initializer_generator.rb
generators/initializer_generator.rb
</shell>
First Rails looks for generators in your application, then in plugins and/or gems, then in your home and finally the builtin generators. One very important thing to keep in mind is that in Rails 3.0 and after it only looks for generators in gems being used in your application. So if you have rspec installed as a gem, but it's not declared in your application, Rails won't be able to invoke it.
If none of them is found, it raises an error message.
h3. Customizing your workflow
@ -183,7 +176,6 @@ $ rails generate scaffold User name:string
create app/views/users/show.html.erb
create app/views/users/new.html.erb
create app/views/users/_form.html.erb
create app/views/layouts/users.html.erb
invoke test_unit
create test/functional/users_controller_test.rb
invoke helper
@ -284,7 +276,7 @@ end
end
</ruby>
Now, when the helper generator is invoked and let's say test unit is configured as test framework, it will try to invoke both +MyHelper::Generators::TestUnitGenerator+ and +TestUnit::Generators::MyHelperGenerator+. Since none of those are defined, we can tell our generator to invoke +TestUnit::Generators::HelperGenerator+ instead, which is defined since it's a Rails hook. To do that, we just need to add:
Now, when the helper generator is invoked and let's say test unit is configured as test framework, it will try to invoke both +MyHelper::Generators::TestUnitGenerator+ and +TestUnit::Generators::MyHelperGenerator+. Since none of those are defined, we can tell our generator to invoke +TestUnit::Generators::HelperGenerator+ instead, which is defined since it's a Rails generator. To do that, we just need to add:
<ruby>
# Search for :helper instead of :my_helper
@ -375,4 +367,6 @@ h3. Changelog
"Lighthouse Ticket":http://rails.lighthouseapp.com/projects/16213-rails-guides/tickets/102
* November 20, 2009: First release version by José Valim
* April 30, 2010: Reviewed by José Valim
* November 20, 2009: First version by José Valim