Class: PropertyList::XmlParser

Inherits:
Object
  • Object
show all
Defined in:
lib/property-list/xml_parser.rb

Instance Method Summary collapse

Constructor Details

#initialize(src) ⇒ XmlParser

Returns a new instance of XmlParser.



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# File 'lib/property-list/xml_parser.rb', line 7

def initialize src
  @lexer = StringScanner.new src
end

Instance Method Details

#parse ⇒ Object 



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# File 'lib/property-list/xml_parser.rb', line 19

def parse
  @lexer.skip(/<\?xml\s+.*?\?>*/m)
  # TODO xml_encoding = xml_declaration.match(/(?:\A|\s)encoding=(?:"(.*?)"|'(.*?)')(?:\s|\Z)/)

  skip_space_and_comments
  # TODO doctype should co-exist with xml
  @lexer.skip(/\s*<!DOCTYPE\s+.*?>/m)
  skip_space_and_comments

  if @lexer.scan(/<plist\s*\b[^\/\>]*\/>/)
    skip_space_and_comments
    if !@lexer.eos?
      syntax_error "unrecognized code after plist tag end"
    end
    return
  end

  plist_open = !!@lexer.scan(/<plist\s*\b.*?(?<!\/)>/m)

  res = parse_object

  skip_space_and_comments
  plist_close = !!@lexer.scan(/<\/plist\s*>/m)
  skip_space_and_comments
  if !@lexer.eos?
    syntax_error "unrecognized code after plist tag end"
  end

  if plist_open ^ plist_close
    syntax_error "mismatched <plist> tag"
  end

  res
end

#parse_object ⇒ Object

pushes obj into stack



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# File 'lib/property-list/xml_parser.rb', line 55

def parse_object
  skip_space_and_comments
  if e = @lexer.scan(/<(true|false|array|dict|data)\s*\/>/m)
    case e[/\w+/]
    when 'true'; true
    when 'false'; false
    when 'array'; []
    when 'dict'; {}
    else; '' # data
    end

  elsif e = @lexer.scan(/<(integer|real|string|date|data)\s*>[^<>]*<\/\1\s*>/m)
    tag = e[/\w+/]
    content = tag_content e

    case tag
    when 'integer'
      content.to_i
    when 'real'
      content.to_f
    when 'string'
      CGI.unescape_html content
    when 'date'
      DateTime.parse content
    else # data
      StringIO.new Base64.decode64 content
    end

  elsif e = @lexer.scan(/<array\s*>/m)
    res = []
    until (skip_space_and_comments; @lexer.scan(/<\/array\s*>/m))
      e = parse_object
      syntax_error 'failed to parse array element' if e.nil?
      res << e
    end
    res

  elsif e = @lexer.scan(/<dict\s*>/)
    res = {}
    until (skip_space_and_comments; @lexer.scan(/<\/dict\s*>/m))
      key_tag = @lexer.scan(/<key\s*>[^<>]*<\/key\s*>/m)
      syntax_error 'failed to parse dict key' if !key_tag

      key = CGI.unescape_html tag_content key_tag
      value = parse_object
      syntax_error 'failed to parse dict value' if value.nil?
      res[key] = value
    end
    res

  else
    nil
  end
end

#skip_space_and_comments ⇒ Object 



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# File 'lib/property-list/xml_parser.rb', line 11

def skip_space_and_comments
  @lexer.skip(%r{(?:
    [\x0A\x0D\u2028\u2029\x09\x0B\x0C\x20]+ # newline and space
    |
    <!--(?:.*?)-->
  )+}mx)
end

#syntax_error(msg) ⇒ Object

Raises:



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# File 'lib/property-list/xml_parser.rb', line 114

def syntax_error msg
  pre = @lexer.string[0...@lexer.pos]
  line = pre.count("\n") + 1
  col = pre.size - pre.rindex("\n")
  raise SyntaxError, msg + " at line: #{line} col: #{col} #{@lexer.inspect}", caller
end

#tag_content(e) ⇒ Object 



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# File 'lib/property-list/xml_parser.rb', line 110

def tag_content e
  e[(e.index('>') + 1)...(e.rindex '<')]
end