Is ruby really an fully object oriented language?

Question

Ruby is fully object oriented language. In ruby, everything is an object & therefore, belongs to some class. for example 5 belongs to Object class

1.9.3p194 :001 > 5.class
 => Fixnum 
1.9.3p194 :002 > 5.class.superclass
 => Integer 
1.9.3p194 :003 > 5.class.superclass.superclass
 => Numeric 
1.9.3p194 :005 > 5.class.superclass.superclass.superclass
 => Object 
1.9.3p194 :006 > 5.class.superclass.superclass.superclass.superclass
 => BasicObject 
1.9.3p194 :007 > 5.class.superclass.superclass.superclass.superclass.superclass
 => nil 

so, we have to call all methods by prefixing class/object name as in Object_name#method_name. example:

5.times{|i| puts i}

now, rails has these so called helpers like stylesheet_link_tag, javascript_include_tag, form_for etc which do follow this Object_name#method_name syntax, so i guess they are just normal functions.

so my question is

1. What are these rails helpers?
2. If they just functions & do not inherit from any class. Doesn't that contradict the claim made saying - in ruby, everything a object & there are no primitives. As the example, people cite 5.+(6) saying even operators are just plain methods?

Answer 1

• ActionView::Helpers
• ActionController::Helpers

For other things called without a receiver, look at the Kernel module, where stuff like puts is defined. Since the module is included in Object, its methods are available everywhere. How exactly would that contradict the -- IMHO overused -- claim that everything is an object?

Answer 2

These rails assets tag helpers are a sub module of ActionView, ActionView::Helpers::AssetTagHelper which provides methods for generating HTML that links views to assets such as images, javascripts, stylesheets, and feed.

As modules have class as a superclass it mean that the AssetTagHelpers will also have it

irb(main):016:0> ActionView::Helpers::AssetTagHelper
=> ActionView::Helpers::AssetTagHelper
irb(main):017:0> ActionView::Helpers::AssetTagHelper.class
=> Module
irb(main):018:0> ActionView::Helpers::AssetTagHelper.class.superclass
=> Object
irb(main):019:0> ActionView::Helpers::AssetTagHelper.class.superclass.superclass
=> BasicObject
irb(main):020:0> ActionView::Helpers::AssetTagHelper.class.superclass.superclass.superclass
=> nil

NOTE: For sake of simplicity I will only focus on the JavascriptIncludeTag but they are all pretty similar.

Here you will find a class called ActionView::Helpers::AssetTagHelper::JavascriptIncludeTag

Which you can be instantiate

JavascriptIncludeTag.new(config, asset_paths) 

The JavascriptIncludeTag class has a method called asset_tag which then calls a content_tag method and returns the correct tag.

path: /actionpack/lib/action_view/helpers/asset_tag_helpers/javascript_tag_helpers.rb

require 'action_view/helpers/asset_tag_helpers/asset_include_tag'

# NOTE: on the 'action_view/helpers/asset_tag_helpers/asset_include_tag' it requires '/actionpack/lib/action_view/helpers/tag_helper.rb' so now all this files are connected :)
.
.
.
def asset_tag(source, options)
  content_tag("script", "", { "src" => path_to_asset(source) }.merge(options))
end

path: /actionpack/lib/action_view/helpers/tag_helper.rb

def content_tag(name, content_or_options_with_block = nil, options = nil, escape = true, &block)
  if block_given?
    options = content_or_options_with_block if content_or_options_with_block.is_a?(Hash)
    content_tag_string(name, capture(&block), options, escape)
  else
    content_tag_string(name, content_or_options_with_block, options, escape)
  end
end

So that is more less how they work.

NOTE: If you found my explanation a bit tricky just let me know and I'll edited to provide a better explanation