Class: REXML::Parsers::PullParser

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Includes:
XMLTokens
Defined in:
lib/rexml/parsers/pullparser.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

Constants included from XMLTokens

XMLTokens::NAME, XMLTokens::NAMECHAR, XMLTokens::NAME_CHAR, XMLTokens::NAME_START_CHAR, XMLTokens::NAME_STR, XMLTokens::NCNAME_STR, XMLTokens::NMTOKEN, XMLTokens::NMTOKENS, XMLTokens::REFERENCE

Instance Method Summary collapse

Constructor Details

#initialize(stream) ⇒ PullParser

Returns a new instance of PullParser.


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# File 'lib/rexml/parsers/pullparser.rb', line 38

def initialize stream
  @entities = {}
  @listeners = nil
  @parser = BaseParser.new( stream )
  @my_stack = []
end

Instance Method Details

#add_listener(listener) ⇒ Object


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# File 'lib/rexml/parsers/pullparser.rb', line 45

def add_listener( listener )
  @listeners = [] unless @listeners
  @listeners << listener
end

#eachObject


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# File 'lib/rexml/parsers/pullparser.rb', line 50

def each
  while has_next?
    yield self.pull
  end
end

#peek(depth = 0) ⇒ Object


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# File 'lib/rexml/parsers/pullparser.rb', line 56

def peek depth=0
  if @my_stack.length <= depth
    (depth - @my_stack.length + 1).times {
      e = PullEvent.new(@parser.pull)
      @my_stack.push(e)
    }
  end
  @my_stack[depth]
end

#pullObject


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# File 'lib/rexml/parsers/pullparser.rb', line 66

def pull
  return @my_stack.shift if @my_stack.length > 0

  event = @parser.pull
  case event[0]
  when :entitydecl
    @entities[ event[1] ] =
      event[2] unless event[2] =~ /PUBLIC|SYSTEM/
  when :text
    unnormalized = @parser.unnormalize( event[1], @entities )
    event << unnormalized
  end
  PullEvent.new( event )
end

#unshift(token) ⇒ Object


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# File 'lib/rexml/parsers/pullparser.rb', line 81

def unshift token
  @my_stack.unshift token
end