如何将 Rails 视图助手提取到 gem 中？
I have a set of rails view helpers that I use regularly, and would like to package them up into a gem, such that I could just put a line in my Gemfile, and have the helpers accessible from my views.
I have created gems before using Bundler, and Jeweler, however, I'm not all all clear on how to organize the Rails view helpers in a gem, and include them into rails.
I would appreciate any pointers, or links to up-to-date tutorials on how to do this for Rails 3
Thanks
Just to clarify: The question isn't on "how to create a gem". Its "how to package view helpers in a gem, so I can use them in Rails"
Edit 2: I also agree with the poster below.. A rails engine is waay too much overkill for this kind of (hopefully simple) requirement
In my opinion, a full Engine is overkill for this task. You could instead just create a Railtie which includes your helpers into ActionView::Base when it initializes.
# lib/my_gem/view_helpers.rb
module MyGem
module ViewHelpers
def pre(text)
content_tag :pre, text
end
def another_helper
# super secret stuff
end
end
end
# lib/my_gem/railtie.rb
require 'my_gem/view_helpers'
module MyGem
class Railtie < Rails::Railtie
initializer "my_gem.view_helpers" do
ActiveSupport.on_load(:action_view) { include MyGem::ViewHelpers }
end
end
end
# lib/my_gem.rb
require 'my_gem/railtie' if defined?(Rails)
Also if you want include helper only for Rails3 version you can use
# lib/my_gem.rb
require 'my_gem/railtie' if defined?(Rails::Railtie)
What you are probably looking for is an engine. An engine is a gem that contains rails application pieces (in fact, a rails application is itself an engine.)
includeonActionView::Base. Rails has offered lazy load hooks as a part of ActiveSupport since 3.0.0. Thus, the alternate code for the initializer block would look likeActiveSupport.on_load( :action_view ){ include MyGem::ViewHelpers }