CODEWITHSUNDEEP
ruby-on-railsruby-on-rails-4
Yarin
Yarin

Reputation: 183549

Auto-loading lib files in Rails 4

I use the following line in an initializer to autoload code in my /lib directory during development:

config/initializers/custom.rb: 

RELOAD_LIBS = Dir[Rails.root + 'lib/**/*.rb'] if Rails.env.development?

(from Rails 3 Quicktip: Auto reload lib folders in development mode)

It works great, but it's too inefficient to use in production- Instead of loading libs on each request, I just want to load them on start up. The same blog has another article describing how to do this:

config/application.rb: 

# Custom directories with classes and modules you want to be autoloadable.
config.autoload_paths += %W(#{config.root}/lib)
config.autoload_paths += Dir["#{config.root}/lib/**/"]

However, when I switch to that, even in development, I get NoMethodErrors when trying to use the lib functions.

Example of one of my lib files:

lib/extensions.rb:

Time.class_eval do
  def self.milli_stamp
    Time.now.strftime('%Y%m%d%H%M%S%L').to_i
  end
end

Calling Time.milli_stamp will throw NoMethodError

I realize others have answered similar questions on SO but they all seem to deal with naming conventions and other issues that I didn't to have to worry about before- My lib classes already worked for per-request loading, I just want to change it to per-startup loading. What's the right way to do this?

Upvotes: 232

Views: 130452

Answers (4)

ifyouseewendy
ifyouseewendy

Reputation: 6674

I think this may solve your problem:

  1. in config/application.rb:

    config.autoload_paths << Rails.root.join('lib')

    and keep the right naming convention in lib.

    in lib/foo.rb:

    class Foo
end

    in lib/foo/bar.rb:

    class Foo::Bar
end

  2. if you really wanna do some monkey patches in file like lib/extensions.rb, you may manually require it:

    in config/initializers/require.rb:

    require "#{Rails.root}/lib/extensions"

P.S.

Upvotes: 550

Madx
Madx

Reputation: 1

Use config.to_prepare to load you monkey patches/extensions for every request in development mode.

config.to_prepare do |action_dispatcher|
 # More importantly, will run upon every request in development, but only once (during boot-up) in production and test.
 Rails.logger.info "\n--- Loading extensions for #{self.class} "
 Dir.glob("#{Rails.root}/lib/extensions/**/*.rb").sort.each do |entry|
   Rails.logger.info "Loading extension(s): #{entry}"
   require_dependency "#{entry}"
 end
 Rails.logger.info "--- Loaded extensions for #{self.class}\n"

end

Upvotes: 0

sameers
sameers

Reputation: 5095

This might help someone like me that finds this answer when searching for solutions to how Rails handles the class loading ... I found that I had to define a module whose name matched my filename appropriately, rather than just defining a class:

In file lib/development_mail_interceptor.rb (Yes, I'm using code from a Railscast :))

module DevelopmentMailInterceptor
  class DevelopmentMailInterceptor
    def self.delivering_email(message)
      message.subject = "intercepted for: #{message.to} #{message.subject}"
      message.to = "[email protected]"
    end
  end
end

works, but it doesn't load if I hadn't put the class inside a module.

Upvotes: 6

lulalala
lulalala

Reputation: 17981

Though this does not directly answer the question, but I think it is a good alternative to avoid the question altogether.

To avoid all the autoload_paths or eager_load_paths hassle, create a "lib" or a "misc" directory under "app" directory. Place codes as you would normally do in there, and Rails will load files just like how it will load (and reload) model files.

Upvotes: 34

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