Verificar a versao do Rails que deve ser a 3.1 ou superior:
$ rvm use 1.9.2@rails3.1
$ rails -v
$ rails plugin new uhoh --mountable
$ cd uhoh
$ git init
$ echo "rvm use 1.9.2@rails3.1" > .rvmrc
create
create README.rdoc
create Rakefile
create uhoh.gemspec
create MIT-LICENSE
create .gitignore
create Gemfile
create app
create app/controllers/uhoh/application_controller.rb
create app/helpers/uhoh/application_helper.rb
create app/models
create app/views/layouts/application.html.erb
create app/views/layouts/uhoh/application.html.erb
create app/assets/images/uhoh
create app/assets/images/uhoh/.gitkeep
create config/routes.rb
create lib/uhoh.rb
create lib/tasks/uhoh_tasks.rake
create lib/uhoh/engine.rb
create app/assets/stylesheets/uhoh/application.css
create app/assets/javascripts/uhoh/application.js
create script
create script/rails
create test/test_helper.rb
create test/uhoh_test.rb
append Rakefile
create test/integration/navigation_test.rb
vendor_app test/dummy
run bundle install
chamada a isolate_namespace, que torna a engine isolada da aplicação onde será montada.
module Uhoh
class Engine < Rails::Engine
isolate_namespace Uhoh
end
end
Engine de Noitificações 1
Criar um controller para a engine:
$ rails generate controller failures index
Uhoh::Engine.routes.draw do
root :to => "failures#index"
end
$ rails generate model failure message:text
$ rake db:migrate
$ rails c
> Uhoh::Failure.create!(:message => 'Ohoh Failure!')
$ rake uhoh:install:migrations
module Uhoh
class FailuresController < ApplicationController
def index
@failures = Failure.all
end
end
end
<h1>Failures</h1>
<ul>
<% for failure in @failures %>
<li><%= failure.message %></li>
<% end %>
</ul>
Configurar um Initializer
Notifier que vai ficar escutando quando a aplicação lança uma exception. Criar um initializer em /uhoh/config/initializers/exception_handler.rb
ActiveSupport::Notifications.subscribe \
"process_action.action_controller" do \
|name, start, finish, id, payload|
if payload[:exception]
name, message = *payload[:exception]
Uhoh::Failure.create!(:message => message)
end
end
Testar a Engine na aplicação Dummy
É possível testar a engine na aplicação ficticia de teste criada em test/dummy:
Informar para aplicação qual url será usada para referênciar a Engine no arquivo /test/dummy/config/routes.rb:
Rails.application.routes.draw do
mount Uhoh::Engine => "/uhoh"
end
$ cd test/dummy
$ rails g controller simulate failure
class SimulateController < ApplicationController
def failure
raise "Simulating an exception"
end
end
Testado tudo numa nova aplicação
Criar a nova aplicação que vai utilizar a engine a partir do path
$ rails new uhoh-parent
$ vi uhoh-pai/Gemfile
#=>incluir esta linha utilizar a engine criada localmente
gem 'uhoh', :path => '../uhoh/'
$ gem build uhoh.gemspec
$ gem install uhoh
$ export BUNDLER_EDITOR=gmate
$ bundle open uhoh
$ bundle exec rake uhoh:install:migrations
$ bundle exec rake db:migrate
$ rails s
Referências:
1 http://railscasts.com/episodes/277-mountable-engines
http://www.builtfromsource.com/2010/12/13/mountable-engines-in-rails-3-1-beta-getting-started/
http://railscasts.com/episodes/249-notifications-in-rails-3
