Class: Ox::Sax

Inherits:
Object
  • Object
show all
Defined in:
lib/ox/sax.rb,
ext/ox/sax_as.c

Overview

A SAX style parse handler. The Ox::Sax handler class should be subclasses and then used with the Ox.sax_parse() method. The Sax methods will then be called as the file is parsed. This is best suited for very large files or IO streams.<p/>

Example

require 'ox'

class MySax < ::Ox::Sax
  def initialize()
    @element_names = []
  end

  def start_element(name)
    @element_names << name
  end
end

any = MySax.new()
File.open('any.xml', 'r') do |f|
  Ox.sax_parse(any, f)
end

To make the desired methods active while parsing the desired method should be made public in the subclasses. If the methods remain private they will not be called during parsing. The 'name' argument in the callback methods will be a Symbol. The 'str' arguments will be a String. The 'value' arguments will be Ox::Sax::Value objects. Since both the text() and the value() methods are called for the same element in the XML document the the text() method is ignored if the value() method is defined or public. The same is true for attr() and attr_value(). When all attributes have been read the attr_done() callback will be invoked.

def instruct(target); end
def end_instruct(target); end
def attr(name, str); end
def attr_value(name, value); end
def attrs_done(); end
def doctype(str); end
def comment(str); end
def cdata(str); end
def text(str); end
def value(value); end
def start_element(name); end
def end_element(name); end
def error(message, line, column); end
def abort(name); end

Initializing line attribute in the initializer will cause that variable to be updated before each callback with the XML line number. The same is true for the column attribute but it will be updated with the column in the XML file that is the start of the element or node just read. @pos if defined will hold the number of bytes from the start of the document.

Direct Known Subclasses

Ox::StreamParser::OxParser

Defined Under Namespace

Classes: Value

Instance Method Summary collapse

Constructor Details

#initializeSax

Create a new instance of the Sax handler class.



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# File 'lib/ox/sax.rb', line 59

def initialize()
  #@pos = nil
  #@line = nil
  #@column = nil
end