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Class: LibXML::XML::SaxParser

Overview

SaxParser provides a callback based API for parsing documents, in contrast to XML::Parser’s tree based API and XML::Reader’s stream based API.

The SaxParser API is fairly complex, not well standardized, and does not directly support validation making entity, namespace and base processing relatively hard.

To use the SaxParser, register a callback class via the #callbacks=. It is easiest to include the Callbacks module in your class and override the methods as needed.

Basic example:

class MyCallbacks
  include XML::SaxParser::Callbacks
  def on_start_element(element, attributes)
    puts #Element started: #{element}"
  end
end

parser = XML::SaxParser.string(my_string)
parser.callbacks = MyCallbacks.new
parser.parse

You can also parse strings (see .string) and io objects (see .io).

Class Method Summary

Instance Attribute Summary

Instance Method Summary

Constructor Details

.new(context) ⇒ XML::Parser

Creates a new Parser from the specified Parser::Context.

[ GitHub ] 

  


# File 'ext/libxml/ruby_xml_sax_parser.c', line 53



static VALUE rxml_sax_parser_initialize(int argc, VALUE *argv, VALUE self)
{
  VALUE context = Qnil;

  rb_scan_args(argc, argv, "01", &context);

  if (context == Qnil)
  {
    rb_raise(rb_eArgError, "An instance of a XML::Parser::Context must be passed to XML::SaxParser.new");
  }

  rb_ivar_set(self, CONTEXT_ATTR, context);
  return self;
}


  







Class Method Details



  

    XML::SaxParser.file(path)  ⇒ SaxParser   



  

    

Creates a new parser by parsing the specified file or uri.


  



  [ GitHub ]


  

  


# File 'lib/libxml/sax_parser.rb', line 10



def self.file(path)
  context = XML::Parser::Context.file(path)
  self.new(context)
end


  








  

    

      XML::SaxParser.io(io)  ⇒ SaxParser 
      XML::SaxParser.io(io, :encoding)  ⇒ XML::Encoding::UTF_8 
    

  



  

    

Creates a new reader by parsing the specified io object.



Parameters:



encoding - The document encoding, defaults to nil. Valid values
           are the encoding constants defined on XML::Encoding.


  





  


  [ GitHub ]


  

  


# File 'lib/libxml/sax_parser.rb', line 25



def self.io(io, options = {})
  context = XML::Parser::Context.io(io)
  context.encoding = options[:encoding] if options[:encoding]
  self.new(context)
end


  








  

    XML::SaxParser.string(string)    



  

    

Creates a new parser by parsing the specified string.


  



  [ GitHub ]


  

  


# File 'lib/libxml/sax_parser.rb', line 35



def self.string(string)
  context = XML::Parser::Context.string(string)
  self.new(context)
end


  







Instance Attribute Details



  

    #callbacks   (rw)
  

  [ GitHub ]





Instance Method Details



  

    #parse  ⇒ Boolean   



  

    

Parse the input ::LibXML::XML, generating callbacks to the object registered via the #callbacks attributesibute.


  



  [ GitHub ]


  

  


# File 'ext/libxml/ruby_xml_sax_parser.c', line 75



static VALUE rxml_sax_parser_parse(VALUE self)
{
  VALUE context = rb_ivar_get(self, CONTEXT_ATTR);
  xmlParserCtxtPtr ctxt;
  Data_Get_Struct(context, xmlParserCtxt, ctxt);

  ctxt->sax2 = 1;
	ctxt->userData = (void*)rb_ivar_get(self, CALLBACKS_ATTR);
  memcpy(ctxt->sax, &rxml_sax_handler, sizeof(rxml_sax_handler));
    
  int status = xmlParseDocument(ctxt);

  /* Now check the parsing result*/
  if (status == -1 || !ctxt->wellFormed)
  {
    rxml_raise(&ctxt->lastError);
  }
  return Qtrue;
}