In Files

  • rexml/parsers/baseparser.rb

REXML::Parsers::BaseParser

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.

Attributes

source[R]

Public Class Methods

new( source ) click to toggle source
 
               # File rexml/parsers/baseparser.rb, line 115
def initialize( source )
  self.stream = source
  @listeners = []
end
            

Public Instance Methods

add_listener( listener ) click to toggle source
 
               # File rexml/parsers/baseparser.rb, line 120
def add_listener( listener )
  @listeners << listener
end
            
empty?() click to toggle source

Returns true if there are no more events

 
               # File rexml/parsers/baseparser.rb, line 146
def empty?
  return (@source.empty? and @stack.empty?)
end
            
entity( reference, entities ) click to toggle source
 
               # File rexml/parsers/baseparser.rb, line 446
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?() click to toggle source

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

 
               # File rexml/parsers/baseparser.rb, line 151
def has_next?
  return !(@source.empty? and @stack.empty?)
end
            
normalize( input, entities=nil, entity_filter=nil ) click to toggle source

Escapes all possible entities

 
               # File rexml/parsers/baseparser.rb, line 457
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) click to toggle source

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.

 
               # File rexml/parsers/baseparser.rb, line 167
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() click to toggle source
 
               # File rexml/parsers/baseparser.rb, line 136
def position
  if @source.respond_to? :position
    @source.position
  else
    # FIXME
    0
  end
end
            
pull() click to toggle source

Returns the next event. This is a PullEvent object.

 
               # File rexml/parsers/baseparser.rb, line 182
def pull
  pull_event.tap do |event|
    @listeners.each do |listener|
      listener.receive event
    end
  end
end
            
stream=( source ) click to toggle source
 
               # File rexml/parsers/baseparser.rb, line 126
def stream=( source )
  @source = SourceFactory.create_from( source )
  @closed = nil
  @document_status = nil
  @tags = []
  @stack = []
  @entities = []
  @nsstack = []
end
            
unnormalize( string, entities=nil, filter=nil ) click to toggle source

Unescapes all possible entities

 
               # File rexml/parsers/baseparser.rb, line 473
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) click to toggle source

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

 
               # File rexml/parsers/baseparser.rb, line 157
def unshift token
  @stack.unshift(token)
end
            

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