module Mail::Multibyte

Multibyte proxy¶ ↑

mb_chars is a multibyte safe proxy for string methods.

In Ruby 1.8 and older it creates and returns an instance of the Mail::Multibyte::Chars class which encapsulates the original string. A Unicode safe version of all the String methods are defined on this proxy class. If the proxy class doesn't respond to a certain method, it's forwarded to the encapsuled string.

name = 'Claus Müller'
name.reverse # => "rell??M sualC"
name.length  # => 13

name.mb_chars.reverse.to_s # => "rellüM sualC"
name.mb_chars.length       # => 12

In Ruby 1.9 and newer mb_chars returns self because String is (mostly) encoding aware. This means that it becomes easy to run one version of your code on multiple Ruby versions.

Method chaining¶ ↑

All the methods on the Chars proxy which normally return a string will return a Chars object. This allows method chaining on the result of any of these methods.

name.mb_chars.reverse.length # => 12

Interoperability and configuration¶ ↑

The Chars object tries to be as interchangeable with String objects as possible: sorting and comparing between String and Char work like expected. The bang! methods change the internal string representation in the Chars object. Interoperability problems can be resolved easily with a to_s call.

For more information about the methods defined on the Chars proxy see Mail::Multibyte::Chars. For information about how to change the default Multibyte behaviour see Mail::Multibyte.

# File lib/mail/multibyte.rb, line 55
def self.mb_chars(str)
  if is_utf8?(str)
    proxy_class.new(str)
  else
    str
  end
end