More readable string method in rails

First look at the code:

Rails.env.development? #=> true

If rails run at local development environment it will return true

Why can call the development? method directly on the Rails.env object?

The point is that you can use ? suffix at method very simple, let's show you source code.

module ActiveSupport
  class StringInquirer < String
    def method_missing(method_name, *arguments)
      if method_name[-1] == "?"
        self == method_name[0..-2]
      else
        super
      end
    end
  end
end

In fact Rails.env is anActiveSupport::StringInquirer instance object. the ActiveSupport::StringInquirer object extends the method_missing of the String class.

Mainly compare the string before ? with the string itself

name = ActiveSupport::StringInquirer.new("mixbo")
name.mixbo? #=>true

'mixbo?'[0..-2] #=> 'mixbo' 
'mixbo' == 'mixbo' #=>true

Hope it can help you :)

Comments

[James]

This is part of the "Rails magic" that I'd never bothered to dig into and learn how it actually works, so this was really cool to read, thank you.

[mixbo]

keep learnning :)