module MDUrl::Encode

Constants

COMPONENT_CHARACTERS
DEFAULT_CHARACTERS

Public Class Methods

encode(string, exclude = nil, keepEscaped = nil) click to toggle source

Encode unsafe characters with percent-encoding, skipping already encoded sequences.

- string       - string to encode
- exclude      - list of characters to ignore (in addition to a-zA-Z0-9)
- keepEscaped  - don't encode '%' in a correct escape sequence (default: true)
# File lib/mdurl-rb/encode.rb, line 45
def self.encode(string, exclude = nil, keepEscaped = nil)
  result = ''

  if !exclude.is_a? String
    # encode(string, keepEscaped)
    keepEscaped = exclude
    exclude = DEFAULT_CHARACTERS
  end

  if keepEscaped == nil
    keepEscaped = true
  end

  cache = getEncodeCache(exclude)

  i = 0
  l = string.length
  while i < l
    code = string[i].ord

    if (keepEscaped && code == 0x25 && i + 2 < l) #  %
      if (/^[0-9a-f]{2}$/i =~ (string.slice((i + 1)...(i + 3))))
        result += string.slice(i...(i + 3))
        i += 3
        next
      end
    end

    if (code < 128)
      result += cache[code]
      i += 1
      next
    end

    if (code >= 0xD800 && code <= 0xDFFF)
      if (code >= 0xD800 && code <= 0xDBFF && i + 1 < l)
        nextCode = string[i + 1].ord
        if (nextCode >= 0xDC00 && nextCode <= 0xDFFF)
          result += CGI::escape(string[i] + string[i + 1])
          i += 2
          next
        end
      end
      result += '%EF%BF%BD'
      i += 1
      next
    end

    result += CGI::escape(string[i])
    i += 1
  end

  return result
end
getEncodeCache(exclude) click to toggle source

Create a lookup array where anything but characters in `chars` string and alphanumeric chars is percent-encoded.

# File lib/mdurl-rb/encode.rb, line 13
def self.getEncodeCache(exclude)
  cache = @@encodeCache[exclude]
  return cache if (cache)

  cache = @@encodeCache[exclude] = []

  (0...128).each do |i|
    ch = i.chr

    if (/^[0-9a-z]$/i =~ ch)
      # always allow unencoded alphanumeric characters
      cache.push(ch)
    else
      cache.push('%' + ('0' + i.to_s(16).upcase).slice(-2, 2))
    end
  end

  (0...exclude.length).each do |i|
    cache[exclude[i].ord] = exclude[i]
  end

  return cache
end