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diff --git a/guides/source/en/rails_application_templates.md b/guides/source/en/rails_application_templates.md new file mode 100644 index 0000000000..ee5fbcfd52 --- /dev/null +++ b/guides/source/en/rails_application_templates.md @@ -0,0 +1,218 @@ +Rails Application Templates +=========================== + +Application templates are simple Ruby files containing DSL for adding gems/initializers etc. to your freshly created Rails project or an existing Rails project. + +By referring to this guide, you will be able to: + +* Use templates to generate/customize Rails applications +* Write your own reusable application templates using the Rails template API + +-------------------------------------------------------------------------------- + +Usage +----- + +To apply a template, you need to provide the Rails generator with the location of the template you wish to apply, using -m option. This can either be path to a file or a URL. + +```bash +$ rails new blog -m ~/template.rb +$ rails new blog -m http://example.com/template.rb +``` + +You can use the rake task `rails:template` to apply templates to an existing Rails application. The location of the template needs to be passed in to an environment variable named LOCATION. Again, this can either be path to a file or a URL. + +```bash +$ rake rails:template LOCATION=~/template.rb +$ rake rails:template LOCATION=http://example.com/template.rb +``` + +Template API +------------ + +Rails templates API is very self explanatory and easy to understand. Here's an example of a typical Rails template: + +```ruby +# template.rb +run "rm public/index.html" +generate(:scaffold, "person name:string") +route "root :to => 'people#index'" +rake("db:migrate") + +git :init +git :add => "." +git :commit => %Q{ -m 'Initial commit' } +``` + +The following sections outlines the primary methods provided by the API: + +### gem(name, options = {}) + +Adds a `gem` entry for the supplied gem to the generated application’s `Gemfile`. + +For example, if your application depends on the gems `bj` and `nokogiri`: + +```ruby +gem "bj" +gem "nokogiri" +``` + +Please note that this will NOT install the gems for you and you will have to run `bundle install` to do that. + +```bash +bundle install +``` + +### gem_group(*names, &block) + +Wraps gem entries inside a group. + +For example, if you want to load `rspec-rails` only in `development` and `test` group: + +```ruby +gem_group :development, :test do + gem "rspec-rails" +end +``` + +### add_source(source, options = {}) + +Adds the given source to the generated application's `Gemfile`. + +For example, if you need to source a gem from "http://code.whytheluckystiff.net": + +```ruby +add_source "http://code.whytheluckystiff.net" +``` + +### vendor/lib/file/initializer(filename, data = nil, &block) + +Adds an initializer to the generated application’s `config/initializers` directory. + +Lets say you like using `Object#not_nil?` and `Object#not_blank?`: + +```ruby +initializer 'bloatlol.rb', <<-CODE + class Object + def not_nil? + !nil? + end + + def not_blank? + !blank? + end + end +CODE +``` + +Similarly `lib()` creates a file in the `lib/` directory and `vendor()` creates a file in the `vendor/` directory. + +There is even `file()`, which accepts a relative path from `Rails.root` and creates all the directories/file needed: + +```ruby +file 'app/components/foo.rb', <<-CODE + class Foo + end +CODE +``` + +That’ll create `app/components` directory and put `foo.rb` in there. + +### rakefile(filename, data = nil, &block) + +Creates a new rake file under `lib/tasks` with the supplied tasks: + +```ruby +rakefile("bootstrap.rake") do + <<-TASK + namespace :boot do + task :strap do + puts "i like boots!" + end + end + TASK +end +``` + +The above creates `lib/tasks/bootstrap.rake` with a `boot:strap` rake task. + +### generate(what, args) + +Runs the supplied rails generator with given arguments. + +```ruby +generate(:scaffold, "person", "name:string", "address:text", "age:number") +``` + +### run(command) + +Executes an arbitrary command. Just like the backticks. Let's say you want to remove the `public/index.html` file: + +```ruby +run "rm public/index.html" +``` + +### rake(command, options = {}) + +Runs the supplied rake tasks in the Rails application. Let's say you want to migrate the database: + +```ruby +rake "db:migrate" +``` + +You can also run rake tasks with a different Rails environment: + +```ruby +rake "db:migrate", :env => 'production' +``` + +### route(routing_code) + +This adds a routing entry to the `config/routes.rb` file. In above steps, we generated a person scaffold and also removed `public/index.html`. Now to make `PeopleController#index` as the default page for the application: + +```ruby +route "root :to => 'person#index'" +``` + +### inside(dir) + +Enables you to run a command from the given directory. For example, if you have a copy of edge rails that you wish to symlink from your new apps, you can do this: + +```ruby +inside('vendor') do + run "ln -s ~/commit-rails/rails rails" +end +``` + +### ask(question) + +`ask()` gives you a chance to get some feedback from the user and use it in your templates. Lets say you want your user to name the new shiny library you’re adding: + +```ruby +lib_name = ask("What do you want to call the shiny library ?") +lib_name << ".rb" unless lib_name.index(".rb") + +lib lib_name, <<-CODE + class Shiny + end +CODE +``` + +### yes?(question) or no?(question) + +These methods let you ask questions from templates and decide the flow based on the user’s answer. Lets say you want to freeze rails only if the user want to: + +```ruby +rake("rails:freeze:gems") if yes?("Freeze rails gems ?") +# no?(question) acts just the opposite. +``` + +### git(:command) + +Rails templates let you run any git command: + +```ruby +git :init +git :add => "." +git :commit => "-a -m 'Initial commit'" +``` |