Module: ActiveSupport::CoreExtensions::String::Multibyte

chars() click to toggle source

# File lib/active_support/core_ext/string/multibyte.rb, line 56
def chars
  ActiveSupport::Deprecation.warn('String#chars has been deprecated in favor of String#mb_chars.', caller)
  mb_chars
end

is_utf8?() click to toggle source

Returns true if the string has UTF-8 semantics (a String used for purely byte resources is unlikely to have them), returns false otherwise.

# File lib/active_support/core_ext/string/multibyte.rb, line 51
def is_utf8?
  ActiveSupport::Multibyte::Chars.consumes?(self)
end

mb_chars() click to toggle source

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 ActiveSupport::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 ActiveSupport::Multibyte::Chars. For information about how to change the default Multibyte behaviour see ActiveSupport::Multibyte.

# File lib/active_support/core_ext/string/multibyte.rb, line 41
def mb_chars
  if ActiveSupport::Multibyte.proxy_class.wants?(self)
    ActiveSupport::Multibyte.proxy_class.new(self)
  else
    self
  end
end

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ActiveSupport::CoreExtensions::String::Multibyte

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Multibyte proxy

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Interoperability and configuration