check for user input and handle blanks

# If you have been programming for all these sickening years, you would have used something like this quite often.

# You are reading user input and it might be having extra spaces, newlines god knows what at the ends, so you write code like this:

foo_data = nil
t_data = nil

# your evil user may have entered only white spaces as input so better you strip them out
if param[:from_data]
  t_data = param[:from_data].strip
  t_data = param[:from_data]

unless t_data.empty?
  foo_data = param[:from_data].strip
  foo_data = "Some other default value you want"
# now you can use foo_data without any fear.

# Follows a real clean implementation of above code, checkout the number of lines reduced.

# Lets first modify the ruby Object class system itself.
class Object
  def nob
    if respond_to?(:empty?)
      return nil if empty?
      if respond_to?(:strip)
        return (strip.empty?) ? nil : (self.strip)

# Now above ruby_hack lets you write code like this:
foo_data = param[:from_data].nob || "Some other default value"

# it will detect if object is a string, then before checking whether string is empty or not, it will strip the white spaces
# from the string. #nob method would return nil if your object was 'blank', otherwise it will return the object itself
# by blank, i mean, if its a string, it shouldn't be nil or "   " or "\n",
# by blank, i mean, not a empty array like: []
# method is polymorphic in nature and operates on any ruby data type. and thats why, i put it in Object class itself.

# But above method is slightly costlier, that your hand cranked if, elses, because it uses ruby specific facility respond_to? for
# giving polymorphic behaviour and so what will you choose?

Leave a Reply

You must be logged in to post a comment.