Mar 11, 2008

Object-Oriented Approach to Blank Checking/Defaulting

Something I constantly find myself doing is checking to see if a value is blank, and returning something else if it is, otherwise the object itself:

birthday.blank? ? '0000-00-00' : birthday

I started thinking about how I could possibly eliminate the need for all these ternary operators, and came up with this:

class Object
  def or_if_blank(value)
    self.respond_to?(:blank) && self.blank? ? value : self

Now we can do something like this:


You could do something similar for nil, though a more general Ruby idiom is to just use the || operator, which does not work for blank.

On another note, if any of you are used to appending a "if object.respond_to?(:method)" predicate, check out this technique using try.

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