How to split a Rails model file into multiple files (not concerns, not modules, just separate files)?

Question

I have a Rails 4 model Foo defined in a single file foo.rb

# app/models/foo.rb
class Foo < ActiveRecord::Base
  def method1
    ...
  end

  def method2
    ...
  end
end

Without any type of class re-definition (eg, without refactoring to use traits or concerns for example), I would like to simply move some of the code to a new file, foo_more.rb

# app/models/foo.rb
require File.expand_path('../foo_more.rb', __FILE__)
class Foo < ActiveRecord::Base
  def method1
    ...
  end
end

# app/models/foo_more.rb
class Foo < ActiveRecord::Base
  def method2
    ...
  end
end

When I do so, using the require, it works BUT does not re-load in dev't after changes to the code in that file.

Is there a way to tell Rails to re-load that new file in development after code changes?

Answer 1

require_dependency File.expand_path('../foo_more.rb', __FILE__)
class Foo < ActiveRecord::Base
  def method1
    ...
  end
end

# app/models/foo_more.rb
class Foo < ActiveRecord::Base
  def method2
    ...
  end
end

require_dependency(file_name, message = "No such file to load -- %s")

Interprets a file using mechanism and marks its defined constants as autoloaded. file_name can be either a string or respond to to_path.

Common Usage:

Use this method in code that absolutely needs a certain constant to be defined at that point. A typical use case is to make constant name resolution deterministic for constants with the same relative name in different namespaces whose evaluation would depend on load order otherwise.

I typically use require_dependency when developing a class or module that resides in my rails app, perhaps in the lib/ dir. A normal require statement does not reload my changes, so I use require_dependency in files that reference my newly developed class or module.

Source

It should be noted that your miles may vary. Some people experience major slow downs when including a new dependency. I believe this will reload the file every time you call Foo.all, Foo.find(1), etc. So, you should probably only do this in development.