Rails Engine - Gems dependencies, how to load them into the application?

Question

I\'m doing an engine here, it works alright in stand alone.

When I transform it into a gem, and load it inside another application, I get a lot of undefined errors,

Answer 1

You can require them manually like Daniel posted, and you can also require them automatically. You need to add dependencies in 3 files:

• yourengine.gemspec

  s.add_dependency "rails", '4.1.0'
  s.add_dependency "sqlite3"
  

• Gemfile

  # Imports dependencies from yourengine.gemspec
  gemspec
  

• lib/yourengine.rb

  # requires all dependencies
  Gem.loaded_specs['yourengine'].dependencies.each do |d|
   require d.name
  end
  
  require 'yourengine/engine'
  
  module Yourengine
  end
  

Update: It's a simplistic demonstration of how to require the dependencies. You should test it and filter unwanted items, for example: require d.name unless d.type == :development (thx @imsinu9)