Class: REXML::Parsers::BaseParser

Inherits:
Object
  • Object
show all
Defined in:
lib/rexml/parsers/baseparser.rb

Overview

Using the Pull Parser

This API is experimental, and subject to change.

parser = PullParser.new( "<a>text<b att='val'/>txet</a>" )
while parser.has_next?
  res = parser.next
  puts res[1]['att'] if res.start_tag? and res[0] == 'b'
end

See the PullEvent class for information on the content of the results. The data is identical to the arguments passed for the various events to the StreamListener API.

Notice that:

parser = PullParser.new( "<a>BAD DOCUMENT" )
while parser.has_next?
  res = parser.next
  raise res[1] if res.error?
end

Nat Price gave me some good ideas for the API.

Constant Summary collapse

LETTER = 
'[:alpha:]'
DIGIT = 
'[:digit:]'
COMBININGCHAR =

TODO

''
EXTENDER =

TODO

''
NCNAME_STR = 
"[#{LETTER}_][-[:alnum:]._#{COMBININGCHAR}#{EXTENDER}]*"
QNAME_STR = 
"(?:(#{NCNAME_STR}):)?(#{NCNAME_STR})"
QNAME = 
/(#{QNAME_STR})/
NAMECHAR = 
'[\-\w\.:]'
NAME = 
"([\\w:]#{NAMECHAR}*)"
NMTOKEN = 
"(?:#{NAMECHAR})+"
NMTOKENS = 
"#{NMTOKEN}(\\s+#{NMTOKEN})*"
REFERENCE = 
"&(?:#{NAME};|#\\d+;|#x[0-9a-fA-F]+;)"
REFERENCE_RE = 
/#{REFERENCE}/
DOCTYPE_START = 
/\A\s*<!DOCTYPE\s/um
DOCTYPE_END = 
/\A\s*\]\s*>/um
DOCTYPE_PATTERN = 
/\s*<!DOCTYPE\s+(.*?)(\[|>)/um
ATTRIBUTE_PATTERN = 
/\s*(#{QNAME_STR})\s*=\s*(["'])(.*?)\4/um
COMMENT_START = 
/\A<!--/u
COMMENT_PATTERN = 
/<!--(.*?)-->/um
CDATA_START = 
/\A<!\[CDATA\[/u
CDATA_END = 
/\A\s*\]\s*>/um
CDATA_PATTERN = 
/<!\[CDATA\[(.*?)\]\]>/um
XMLDECL_START = 
/\A<\?xml\s/u
XMLDECL_PATTERN = 
/<\?xml\s+(.*?)\?>/um
INSTRUCTION_START = 
/\A<\?/u
INSTRUCTION_PATTERN = 
/<\?#{NAME}(\s+.*?)?\?>/um
TAG_MATCH = 
/^<((?>#{QNAME_STR}))/um
CLOSE_MATCH = 
/^\s*<\/(#{QNAME_STR})\s*>/um
VERSION = 
/\bversion\s*=\s*["'](.*?)['"]/um
ENCODING = 
/\bencoding\s*=\s*["'](.*?)['"]/um
STANDALONE = 
/\bstandalone\s*=\s*["'](.*?)['"]/um
ENTITY_START = 
/\A\s*<!ENTITY/
IDENTITY = 
/^([!\*\w\-]+)(\s+#{NCNAME_STR})?(\s+["'](.*?)['"])?(\s+['"](.*?)["'])?/u
ELEMENTDECL_START = 
/\A\s*<!ELEMENT/um
ELEMENTDECL_PATTERN = 
/\A\s*(<!ELEMENT.*?)>/um
SYSTEMENTITY = 
/\A\s*(%.*?;)\s*$/um
ENUMERATION = 
"\\(\\s*#{NMTOKEN}(?:\\s*\\|\\s*#{NMTOKEN})*\\s*\\)"
NOTATIONTYPE = 
"NOTATION\\s+\\(\\s*#{NAME}(?:\\s*\\|\\s*#{NAME})*\\s*\\)"
ENUMERATEDTYPE = 
"(?:(?:#{NOTATIONTYPE})|(?:#{ENUMERATION}))"
ATTTYPE = 
"(CDATA|ID|IDREF|IDREFS|ENTITY|ENTITIES|NMTOKEN|NMTOKENS|#{ENUMERATEDTYPE})"
ATTVALUE = 
"(?:\"((?:[^<&\"]|#{REFERENCE})*)\")|(?:'((?:[^<&']|#{REFERENCE})*)')"
DEFAULTDECL = 
"(#REQUIRED|#IMPLIED|(?:(#FIXED\\s+)?#{ATTVALUE}))"
ATTDEF = 
"\\s+#{NAME}\\s+#{ATTTYPE}\\s+#{DEFAULTDECL}"
ATTDEF_RE = 
/#{ATTDEF}/
ATTLISTDECL_START = 
/\A\s*<!ATTLIST/um
ATTLISTDECL_PATTERN = 
/\A\s*<!ATTLIST\s+#{NAME}(?:#{ATTDEF})*\s*>/um
NOTATIONDECL_START = 
/\A\s*<!NOTATION/um
PUBLIC = 
/\A\s*<!NOTATION\s+(\w[\-\w]*)\s+(PUBLIC)\s+(["'])(.*?)\3(?:\s+(["'])(.*?)\5)?\s*>/um
SYSTEM = 
/\A\s*<!NOTATION\s+(\w[\-\w]*)\s+(SYSTEM)\s+(["'])(.*?)\3\s*>/um
TEXT_PATTERN = 
/\A([^<]*)/um
PUBIDCHAR =

Entity constants

"\x20\x0D\x0Aa-zA-Z0-9\\-()+,./:=?;!*@$_%#"
SYSTEMLITERAL = 
%Q{((?:"[^"]*")|(?:'[^']*'))}
PUBIDLITERAL = 
%Q{("[#{PUBIDCHAR}']*"|'[#{PUBIDCHAR}]*')}
EXTERNALID = 
"(?:(?:(SYSTEM)\\s+#{SYSTEMLITERAL})|(?:(PUBLIC)\\s+#{PUBIDLITERAL}\\s+#{SYSTEMLITERAL}))"
NDATADECL = 
"\\s+NDATA\\s+#{NAME}"
PEREFERENCE = 
"%#{NAME};"
ENTITYVALUE = 
%Q{((?:"(?:[^%&"]|#{PEREFERENCE}|#{REFERENCE})*")|(?:'([^%&']|#{PEREFERENCE}|#{REFERENCE})*'))}
PEDEF = 
"(?:#{ENTITYVALUE}|#{EXTERNALID})"
ENTITYDEF = 
"(?:#{ENTITYVALUE}|(?:#{EXTERNALID}(#{NDATADECL})?))"
PEDECL = 
"<!ENTITY\\s+(%)\\s+#{NAME}\\s+#{PEDEF}\\s*>"
GEDECL = 
"<!ENTITY\\s+#{NAME}\\s+#{ENTITYDEF}\\s*>"
ENTITYDECL = 
/\s*(?:#{GEDECL})|(?:#{PEDECL})/um
EREFERENCE = 
/&(?!#{NAME};)/
DEFAULT_ENTITIES = 
{
  'gt' => [/&gt;/, '&gt;', '>', />/],
  'lt' => [/&lt;/, '&lt;', '<', /</],
  'quot' => [/&quot;/, '&quot;', '"', /"/],
  "apos" => [/&apos;/, "&apos;", "'", /'/]
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(source) ⇒ BaseParser

Returns a new instance of BaseParser.



111
112
113
114
 
# File 'lib/rexml/parsers/baseparser.rb', line 111

def initialize( source )
  self.stream = source
  @listeners = []
end

Instance Attribute Details

#source ⇒ Object (readonly)

Returns the value of attribute source.



120
121
122
 
# File 'lib/rexml/parsers/baseparser.rb', line 120

def source
  @source
end

Instance Method Details

#add_listener(listener) ⇒ Object 



116
117
118
 
# File 'lib/rexml/parsers/baseparser.rb', line 116

def add_listener( listener )
  @listeners << listener
end

#empty? ⇒ Boolean

Returns true if there are no more events

Returns:

  • (Boolean) 


142
143
144
 
# File 'lib/rexml/parsers/baseparser.rb', line 142

def empty?
  return (@source.empty? and @stack.empty?)
end

#entity(reference, entities) ⇒ Object 



409
410
411
412
413
414
415
416
417
 
# File 'lib/rexml/parsers/baseparser.rb', line 409

def entity( reference, entities )
  value = nil
  value = entities[ reference ] if entities
  if not value
    value = DEFAULT_ENTITIES[ reference ]
    value = value[2] if value
  end
  unnormalize( value, entities ) if value
end

#has_next? ⇒ Boolean

Returns true if there are more events. Synonymous with !empty?

Returns:

  • (Boolean) 


147
148
149
 
# File 'lib/rexml/parsers/baseparser.rb', line 147

def has_next?
  return !(@source.empty? and @stack.empty?)
end

#normalize(input, entities = nil, entity_filter = nil) ⇒ Object

Escapes all possible entities



420
421
422
423
424
425
426
427
428
429
430
431
432
433
 
# File 'lib/rexml/parsers/baseparser.rb', line 420

def normalize( input, entities=nil, entity_filter=nil )
  copy = input.clone
  # Doing it like this rather than in a loop improves the speed
  copy.gsub!( EREFERENCE, '&amp;' )
  entities.each do |key, value|
    copy.gsub!( value, "&#{key};" ) unless entity_filter and
                                entity_filter.include?(entity)
  end if entities
  copy.gsub!( EREFERENCE, '&amp;' )
  DEFAULT_ENTITIES.each do |key, value|
    copy.gsub!( value[3], value[1] )
  end
  copy
end

#peek(depth = 0) ⇒ Object

Peek at the depth event in the stack. The first element on the stack is at depth 0. If depth is -1, will parse to the end of the input stream and return the last event, which is always :end_document. Be aware that this causes the stream to be parsed up to the depth event, so you can effectively pre-parse the entire document (pull the entire thing into memory) using this method.



163
164
165
166
167
168
169
170
171
172
173
174
175
 
# File 'lib/rexml/parsers/baseparser.rb', line 163

def peek depth=0
  raise %Q[Illegal argument "#{depth}"] if depth < -1
  temp = []
  if depth == -1
    temp.push(pull()) until empty?
  else
    while @stack.size+temp.size < depth+1
      temp.push(pull())
    end
  end
  @stack += temp if temp.size > 0
  @stack[depth]
end

#position ⇒ Object 



132
133
134
135
136
137
138
139
 
# File 'lib/rexml/parsers/baseparser.rb', line 132

def position
  if @source.respond_to? :position
    @source.position
  else
    # FIXME
    0
  end
end

#pull ⇒ Object

Returns the next event. This is a PullEvent object.



178
179
180
181
182
183
184
 
# File 'lib/rexml/parsers/baseparser.rb', line 178

def pull
  pull_event.tap do |event|
    @listeners.each do |listener|
      listener.receive event
    end
  end
end

#stream=(source) ⇒ Object 



122
123
124
125
126
127
128
129
130
 
# File 'lib/rexml/parsers/baseparser.rb', line 122

def stream=( source )
  @source = SourceFactory.create_from( source )
  @closed = nil
  @document_status = nil
  @tags = []
  @stack = []
  @entities = []
  @nsstack = []
end

#unnormalize(string, entities = nil, filter = nil) ⇒ Object

Unescapes all possible entities



436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
 
# File 'lib/rexml/parsers/baseparser.rb', line 436

def unnormalize( string, entities=nil, filter=nil )
  rv = string.clone
  rv.gsub!( /\r\n?/, "\n" )
  matches = rv.scan( REFERENCE_RE )
  return rv if matches.size == 0
  rv.gsub!( /&#0*((?:\d+)|(?:x[a-fA-F0-9]+));/ ) {
    m=$1
    m = "0#{m}" if m[0] == ?x
    [Integer(m)].pack('U*')
  }
  matches.collect!{|x|x[0]}.compact!
  if matches.size > 0
    matches.each do |entity_reference|
      unless filter and filter.include?(entity_reference)
        entity_value = entity( entity_reference, entities )
        if entity_value
          re = /&#{entity_reference};/
          rv.gsub!( re, entity_value )
        else
          er = DEFAULT_ENTITIES[entity_reference]
          rv.gsub!( er[0], er[2] ) if er
        end
      end
    end
    rv.gsub!( /&amp;/, '&' )
  end
  rv
end

#unshift(token) ⇒ Object

Push an event back on the head of the stream. This method has (theoretically) infinite depth.



153
154
155
 
# File 'lib/rexml/parsers/baseparser.rb', line 153

def unshift token
  @stack.unshift(token)
end