Truncate string with Rails?

Question

I want to truncate a string as follows:

input:

string = \"abcd asfsa sadfsaf safsdaf aaaaaaaaaa aaaaaaaaaa ffffdffffdffffdffffddd\"

Answer 1

Truncate with Custom Omission

Similar to what some others have suggested here, you can use Rails' #truncate method and use a custom omission that is actually the last part of your string:

string = "abcd asfsa sadfsaf safsdaf aaaaaaaaaa aaaaaaaaaa ffffdffffdffffdffffffffd"

truncate(string, length: 37, omission: "...#{string[-5, 5]}")
# => "abcd asfsa sadfsaf safsdaf aa...ffffffffd"

Exactly what you wanted.

Bonus Points

You might want to wrap this up in a custom method called something like truncate_middle that does some fancy footwork for you:

# Truncate the given string but show the last five characters at the end.
#
def truncate_middle( string, options = {} )
  options[:omission] = "...#{string[-5, 5]}"    # Use last 5 chars of string.

  truncate( string, options )
end

And then just call it like so:

string = "abcd asfsa sadfsaf safsdaf aaaaaaaaaa aaaaaaaaaa ffffdffffdffffdffffffffd"

truncate_middle( string, length: 37 )
# => "abcd asfsa sadfsaf safsdaf aa...ffffffffd"

Boom!

Thanks for asking about this. I think it's a useful way to show a snippet of a longer piece of text.