Module: GuessHtmlEncoding

Defined in:
lib/guess_html_encoding.rb,
lib/guess_html_encoding/version.rb

Overview

A small and simple library for guessing the encoding of HTML in Ruby 1.9.

Constant Summary collapse

VERSION = 
"0.0.8"

Class Method Summary collapse

Class Method Details

.encode(html, headers = nil) ⇒ Object

Force an HTML string into a guessed encoding.



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# File 'lib/guess_html_encoding.rb', line 43

def self.encode(html, headers = nil)
  html_copy = html.to_s.dup
  encoding = guess(html_copy, (headers || '').gsub(/[\r\n]+/, "\n"))
  html_copy.force_encoding(encoding_loaded?(encoding) ? encoding : "UTF-8")
  if html_copy.valid_encoding?
    html_copy
  else
    html_copy.force_encoding('ASCII-8BIT').encode('UTF-8', :undef => :replace, :invalid => :replace)
  end
end

.encoding_loaded?(encoding) ⇒ Boolean

Is this encoding loaded?

Returns:

  • (Boolean) 


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# File 'lib/guess_html_encoding.rb', line 55

def self.encoding_loaded?(encoding)
  !!Encoding.find(encoding) rescue nil
end

.guess(html, headers = nil) ⇒ Object

Guess the encoding of an HTML string, using HTTP headers if provided. HTTP headers can be a string or a hash.



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# File 'lib/guess_html_encoding.rb', line 6

def self.guess(html, headers = nil)
  html = html.to_s.dup.force_encoding("ASCII-8BIT")
  out = nil

  if headers
    headers = headers.map {|k, v| "#{k}: #{v}" }.join("\n") if headers.is_a?(Hash)
    headers = headers.dup.force_encoding("ASCII-8BIT")
    headers.split("\n").map {|i| i.split(":")}.each do |k,v|
      if k =~ /Content-Type/i && v =~ /charset=([\w\d-]+);?/i
        out = $1.upcase
        break
      end
    end
  end

  if out.nil? || out.empty? || !encoding_loaded?(out)
    if html =~ /<meta[^>]*HTTP-EQUIV=["']?Content-Type["']?[^>]*content=["']([^'"]*)["']/i && $1 =~ /charset=([\w\d-]+);?/i
      out = $1
    elsif html =~ /<meta\s+charset=["']([\w\d-]+)?/i
      out = $1
    end
    out.upcase! unless out.nil?
  end

  # Translate encodings with other names.
  if out
    out = "UTF-8" if %w[DEFAULT UTF8 UNICODE].include?(out)
    out = "CP1251" if out == "CP-1251"
    out = "ISO-8859-1" if %w[LATIN1 LATIN-1].include?(out)
    out = "WINDOWS-1250" if %w[WIN-1251 WIN1251].include?(out)
    out = "GB18030" if %w[GB2312 GB18030].include?(out) 
  end

  out
end