After more discussion, it has be agreed that this kind
of changes within reasonable margins are OK for 3.1.
That is, it is fine to change a little bit the generators
even if that means examples in existing books won't be
exact. (Note that the singular csrf_meta_tag exists as an
alias and thus those outdated examples will run, same for
existing applications.)
After that commit, developers can set ENGINE_PATH in ENGINE/scripts/rails
file and load application's ./script/rails (most of the time it will be
dummy application used for testing). When running ./script/rails g it will
use application to boot up, but then it will use Engine's root and
configuration for generators.
With config.generators becomes a way to configure generators
for current instance only. For example:
module Blog
class Engine < Rails::Engine
config.generators do |g|
g.orm :active_record
end
config.app_generators do |g|
g.test_framework :rspec
end
end
end
such definition sets :active_record as orm for engine and :rspec
as test_framework for application. The values set with app_generators
can be overwritten in application using config.generators as you would
normally do:
module MyApp
class Application < Rails::Application
config.generators do |g|
g.test_framework :test_unit
end
end
end
Sometimes it's easier to define routes inside Engine or
Application class definition (e.g. one file applications). The
problem with such case is that if there is a plugin that
has config/routes.rb file, it will trigger routes reload on application.
Since routes definition for application is not in config/routes.rb
file routes_reloader will fail to reload application's routes
properly. With this commit you can pass routes definition as a block
to routes method, which will allow to properly reload it:
class MyApp::Application < Rails::Application
routes do
resources :users
end
end
In order to run Engine as standalone application, you will need
Rails::Application instance in the same namespace that engine
one. It's very important to leave _railtie bound to whatever
used "namespace" method first.
