Module: JSON

Defined in:
lib/facets/json.rb

Overview

This module is the namespace for all the JSON related classes. It also defines some module functions to expose a nicer API to users, instead of using the parser and other classes directly.

Defined Under Namespace

Classes: Parser, State

Constant Summary collapse

JSONError =

The base exception for JSON errors.

Class.new StandardError
ParserError =

This exception is raise, if a parser error occurs.

Class.new JSONError
UnparserError =

This exception is raise, if a unparser error occurs.

Class.new JSONError
CircularDatastructure =

If a circular data structure is encountered while unparsing this exception is raised.

Class.new UnparserError

Class Method Summary collapse

Class Method Details

.parse(source) ⇒ Object

Parse the JSON string source into a Ruby data structure and return it.



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# File 'lib/facets/json.rb', line 459

def parse(source)
  Parser.new(source).parse
end

.pretty_unparse(obj) ⇒ Object

Unparse the Ruby data structure obj into a JSON string and return it. The returned string is a prettier form of the string returned by #unparse.



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# File 'lib/facets/json.rb', line 472

def pretty_unparse(obj)
  state = JSON::State.new(
    :indent     => '  ',
    :space      => ' ',
    :object_nl  => "\n",
    :array_nl   => "\n"
  )
  obj.to_json(state)
end

.support_unicode=(enable) ⇒ Object

Switches on Unicode support, if enable is true. Otherwise switches Unicode support off.



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# File 'lib/facets/json.rb', line 156

def support_unicode=(enable)
  @support_unicode = enable
end

.support_unicode? ⇒ Boolean

Returns true if JSON supports unicode, otherwise false is returned.

Returns:

  • (Boolean) 


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# File 'lib/facets/json.rb', line 161

def support_unicode?
  !!@support_unicode
end

.unparse(obj, state = nil) ⇒ Object

Unparse the Ruby data structure obj into a single line JSON string and return it. state is a JSON::State object, that can be used to configure the output further.



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# File 'lib/facets/json.rb', line 466

def unparse(obj, state = nil)
  obj.to_json(JSON::State.from_state(state))
end

.utf16_to_utf8(string) ⇒ Object

Convert string from UTF16 (big endian) encoding to UTF8 encoding and return it.



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# File 'lib/facets/json.rb', line 410

def utf16_to_utf8(string)
  bytes = '' << string[0, 2].to_i(16) << string[2, 2].to_i(16)
  JSON::UTF16toUTF8.iconv(bytes)
end

.utf8_to_json(string) ⇒ Object

Convert a UTF8 encoded Ruby string string to a JSON string, encoded with UTF16 big endian characters as u????, and return it.



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# File 'lib/facets/json.rb', line 417

def utf8_to_json(string)
  i, n, result = 0, string.size, ''
  while i < n
    char = string[i]
    case
    when char == ?\b then result << '\b'
    when char == ?\t then result << '\t'
    when char == ?\n then result << '\n'
    when char == ?\f then result << '\f'
    when char == ?\r then result << '\r'
    when char == ?"  then result << '\"'
    when char == ?\\ then result << '\\\\'
    when char.between?(0x0, 0x1f) then result << "\\u%04x" % char
    when char.between?(0x20, 0x7f) then result << char
    when !(JSON.support_unicode? && $KCODE == 'UTF8')
      # if utf8 mode is switched off or unicode not supported, just pass
      # bytes through:
      result << char
    when char & 0xe0 == 0xc0
      result << '\u' << utf8_to_utf16(string[i, 2])
      i += 1
    when char & 0xf0 == 0xe0
      result << '\u' << utf8_to_utf16(string[i, 3])
      i += 2
    when char & 0xf8 == 0xf0
      result << '\u' << utf8_to_utf16(string[i, 4])
      i += 3
    when char & 0xfc == 0xf8
      result << '\u' << utf8_to_utf16(string[i, 5])
      i += 4
    when char & 0xfe == 0xfc
      result << '\u' << utf8_to_utf16(string[i, 6])
      i += 5
    else
      raise JSON::UnparserError, "Encountered unknown UTF-8 byte: %x!" % char
    end
    i += 1
  end
  result
end

.utf8_to_utf16(string) ⇒ Object

Convert string from UTF8 encoding to UTF16 (big endian) encoding and return it.



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# File 'lib/facets/json.rb', line 404

def utf8_to_utf16(string)
  JSON::UTF8toUTF16.iconv(string).unpack('H*')[0]
end