module ScrubRb

Constants

VERSION

Public Class Methods

scrub(str, replacement=nil, &block) click to toggle source

static function implementation of String#scrub, where first arg is the string.

ScrubRb.scrub("abc\u3042\x81") #=> "abc\u3042\uFFFD"
ScrubRb.scrub("abc\u3042\x81", "*") #=> "abc\u3042*"
ScrubRb.scrub("abc\u3042\xE3\x80") {|bytes| '<'+bytes.unpack('H*')[0]+'>' } #=> "abc\u3042<e380>"

# File lib/scrub_rb.rb, line 12
def self.scrub(str, replacement=nil, &block)
  return str if str.nil?

  if replacement.nil? && ! block_given?
    replacement =
       # UTF-8 for unicode replacement char \uFFFD, encode in
       # encoding of input string, using '?' as a fallback where
       # it can't be (which should be non-unicode encodings)
       "\xEF\xBF\xBD".force_encoding("UTF-8").encode( str.encoding,
                                                :undef => :replace,
                                                :replace => '?' )  
  end

  result          = "".force_encoding("BINARY")
  bad_chars       = "".force_encoding("BINARY")
  bad_char_flag   = false # weirdly, optimization to use flag

  str.chars.each do |c|
    if c.valid_encoding?
      if bad_char_flag
        scrub_replace(result, bad_chars, replacement, block)
        bad_char_flag = false
      end
      result << c
    else
      bad_char_flag = true
      bad_chars << c
    end
  end
  if bad_char_flag
    scrub_replace(result, bad_chars, replacement, block)
  end

  result.force_encoding(str.encoding)

  return result
end

Private Class Methods

scrub_replace(result, bad_chars, replacement, block) click to toggle source

# File lib/scrub_rb.rb, line 51
def self.scrub_replace(result, bad_chars, replacement, block)
  if block
    r = block.call(bad_chars)
  else
    r = replacement
  end

  if r.respond_to?(:to_str)
    r = r.to_str
  else
    raise TypeError, "no implicit conversion of #{r.class} into String"
  end

  unless r.valid_encoding?
    raise ArgumentError,  "replacement must be valid byte sequence '#{replacement}'"
  end

  result << r
  bad_chars.clear
end