Best practice for handling strings like a boss

your_presence_is_present.rb

# Notes on the Object#blank?, Object#present?, and Object#presence methods
 
# Calling .present? on an object will return true if the object is not .blank?
# Again, for clarity, an object is present if it is not blank.
 
# Thus
"".present? # => false
 
# Because
"".blank? # => true
 
# And
"string".present? # => true
 
# Quite literally, the source for .pressent?
# File activesupport/lib/active_support/core_ext/object/blank.rb, line 19
def present?
  !blank?
end
 
# All you need to know is that .present? returns true or false
# This allows us to protect against strings that would otherwise error out programs.
 
state   = params[:state]   if params[:state].present?
country = params[:country] if params[:country].present?
region  = state || country || 'US'
 
# Very useful!
# But we can improve this a step further by implementing the .presence method
# Calling .presence on an object will return the object itself if it is .present?
 
# Thus
"string".presence # => "string"
 
# And
"".presence # => nil (which evaluates to false)
 
# So, essentially, .presence returns the object that called it or false
 
# Here's the source.
# File activesupport/lib/active_support/core_ext/object/blank.rb, line 37
def presence
  self if present?
end
 
# So our code above could be refactored to
region = params[:state].presence || params[:country].presence || 'US'
 
# Pretty significant improvement.

# In summation:

"".blank?   # => true
"".present? # => false
"".presence # => nil

"string".blank? # => false
"string".present? # => true
"string".presence # => "string"

# This can be a powerful tool in learning how to handle empty strings and conditionals.