To self. or not to self.

Josh Clayton

![Et tu, Brute?]

Off with his head

Ruby developers have gone back and forth for ages as to whether to use self. on their method calls. Why is everyone bickering? Can’t we all just get along?

My guess is that we can’t.

This argument is similar to that of the use of whitespace. Some people are picky while others are not; however, almost all have a very strong opinion.

This above all: to thine own self be true

I prefer to qualify all public instance method calls with self.. I’m one to lean towards being explicit versus implicit, and self. helps me achieve this goal. This also makes coworkers (or any other individual reading the code) aware of whether the method call is an attribute defined by ActiveRecord or a public instance method on the class. The reason this is an issue is because local or block-level variables will never be prefixed with self. - it’s much easier on the eyes to be able to tell immediately whether you’re dealing with one or the other.

Tempt not a desperate man

The explicitness of self. may be construed as line noise. You may also be asked why you don’t use Hungarian notation. Using self. isn’t a naming convention; it’s defining the receiver of the message explicitly. There’s no misconception and you’re relaying intent very plainly by adding five characters.

This is the long and short of it 

class User < ActiveRecord::Base
  before_save :sanitize_names

  def display_name
    return email if first_name.blank?
    [first_name, last_name].compact.join(" ")
  end

  protected

  def sanitize_names
    self.first_name = nil if first_name.blank?
    self.last_name = nil if last_name.blank?
  end
end

The result, after everything is said and done, would be:

class User < ActiveRecord::Base
  before_save :sanitize_names

  def display_name
    return self.email if self.first_name.blank?
    [self.first_name, self.last_name].compact.join(" ")
  end

  protected

  def sanitize_names
    self.first_name = nil if self.first_name.blank?
    self.last_name = nil if self.last_name.blank?
  end
end

Although there may not me much of a different to the casual reader, the second is, in my mind, worlds easier to comprehend.