xml::sax::expat::incremental(3pm) [debian man page]

XML::SAX::Expat::Incremental(3pm)			User Contributed Perl Documentation			 XML::SAX::Expat::Incremental(3pm)

NAME

       XML::SAX::Expat::Incremental - XML::SAX::Expat subclass for non-blocking (incremental) parsing, with XML::Parser::ExpatNB.

SYNOPSIS

	       use XML::SAX::Expat::Incremental;

	       # don't do this, use XML::SAX::ParserFactory
	       my $p = XML::SAX::Expat::Incremental->new( Handler => MyHandler->new );

	       $p->parse_start;

	       while (<DATA>){
		       $p->parse_more($_); # or $p->parse_string($_);
	       }

	       $p->parse_done;

DESCRIPTION

       Most XML parsers give a callback interface within an encapsulated loop. That is, you call

	       $p->parse_whatever($whatever);

       And eventually, when $whatever is depleted by the parser, "$p->parse" will return.

       Sometimes you don't want the parser to control the loop for you. For example, if you need to retrieve your XML in chunks in a funny way,
       you might need to do something like

	       my $doc = '';
	       while (defined(my $buffer = get_more_xml())) {
		       $doc .= $buffer;
	       }

	       $p->parse_string($doc);

       which is not very convenient, or efficient. You could use perltie to tie a filehandle which does this for you, but that only works some of
       the time (for example, say you have two inputs coming in simultaneously).

       XML::Parser::ExpatNB solves this by providing three methods:

       parse_start
       parse_more
       parse_done

       This interface lets you move the loop to outside the parser, retaining control.

       The callbacks are executed in the same manner, just that now, when there is no left to parse, instead of taking more data from a source on
       it's own, the parser returns control to you.

	       $p->parse_start; # you can omit this - parse_start will
				# be called automatically as needed

	       while(defined(my $buffer = get_more_xml())) {
		       $p->parse_more($buffer);
	       }

	       $p->parse_done;

       This module is a subclass of XML::SAX::Expat which is to XML::Parser::ExpatXS as XML::SAX::Expat is to XML::Parser itself.

METHODS

       parse_string STRING
       parse_more STRING
	   These have the same effect, except that parse_more actually calls parse_string with @_. You might want to use parse_string because in
	   theory it's more efficient.

	   This simply continues parsing with the new string, and sends SAX events for the data that is complete in the string.

       parse_start
	   This calls parse_start on the underlying XML::Parser::ExpatNB object. It's called implicitly when you first call parse_string, though,
	   so you don't have to worry about it.

       parse_done
	   This calls parse_done on the underlying XML::Parser::ExpatNB object. You use it to tell the parser you have no more data to give it.

       parse
	   This is used internally as a sort of parse-anything method. Don't use it, instead use "parse_string", which invokes this method
	   correctly, and takes simpler options.

SEE ALSO

       XML::Parser, XML::SAX, XML::SAX::Expat, XML::SAX::ExpatNB

VERSION CONTROL

       This module is maintained using Darcs. You can get the latest version from http://nothingmuch.woobling.org/XML-SAX-Expat-Incremental/
       <http://nothingmuch.woobling.org/XML-SAX-Expat-Incremental/>, and use "darcs send" to commit changes.

AUTHOR

       Yuval Kogman <nothingmuch@woobling.org>

COPYRIGHT &; LICENSE
	       Copyright (c) 2005 Yuval Kogman. All rights reserved
	       This program is free software; you can redistribute
	       it and/or modify it under the same terms as Perl itself.

perl v5.12.4							    2007-09-18					 XML::SAX::Expat::Incremental(3pm)

SAX::ParserFactory(3)					User Contributed Perl Documentation				     SAX::ParserFactory(3)

NAME

       XML::SAX::ParserFactory - Obtain a SAX parser

SYNOPSIS

	 use XML::SAX::ParserFactory;
	 use XML::SAX::XYZHandler;
	 my $handler = XML::SAX::XYZHandler->new();
	 my $p = XML::SAX::ParserFactory->parser(Handler => $handler);
	 $p->parse_uri("foo.xml");
	 # or $p->parse_string("<foo/>") or $p->parse_file($fh);

DESCRIPTION

       XML::SAX::ParserFactory is a factory class for providing an application with a Perl SAX2 XML parser. It is akin to DBI - a front end for
       other parser classes. Each new SAX2 parser installed will register itself with XML::SAX, and then it will become available to all
       applications that use XML::SAX::ParserFactory to obtain a SAX parser.

       Unlike DBI however, XML/SAX parsers almost all work alike (especially if they subclass XML::SAX::Base, as they should), so rather than
       specifying the parser you want in the call to "parser()", XML::SAX has several ways to automatically choose which parser to use:

       o   $XML::SAX::ParserPackage

	   If this package variable is set, then this package is "require()"d and an instance of this package is returned by calling the "new()"
	   class method in that package. If it cannot be loaded or there is an error, an exception will be thrown. The variable can also contain a
	   version number:

	     $XML::SAX::ParserPackage = "XML::SAX::Expat (0.72)";

	   And the number will be treated as a minimum version number.

       o   Required features

	   It is possible to require features from the parsers. For example, you may wish for a parser that supports validation via a DTD. To do
	   that, use the following code:

	     use XML::SAX::ParserFactory;
	     my $factory = XML::SAX::ParserFactory->new();
	     $factory->require_feature('http://xml.org/sax/features/validation');
	     my $parser = $factory->parser(...);

	   Alternatively, specify the required features in the call to the ParserFactory constructor:

	     my $factory = XML::SAX::ParserFactory->new(
		     RequiredFeatures => {
			  'http://xml.org/sax/features/validation' => 1,
			  }
		     );

	   If the features you have asked for are unavailable (for example the user might not have a validating parser installed), then an
	   exception will be thrown.

	   The list of known parsers is searched in reverse order, so it will always return the last installed parser that supports all of your
	   requested features (Note: this is subject to change if someone comes up with a better way of making this work).

       o   SAX.ini

	   ParserFactory will search @INC for a file called SAX.ini, which is in a simple format:

	     # a comment looks like this,
	     ; or like this, and are stripped anywhere in the file
	     key = value # SAX.in contains key/value pairs.

	   All whitespace is non-significant.

	   This file can contain either a line:

	     ParserPackage = MyParserModule (1.02)

	   Where MyParserModule is the module to load and use for the parser, and the number in brackets is a minimum version to load.

	   Or you can list required features:

	     http://xml.org/sax/features/validation = 1

	   And each feature with a true value will be required.

       o   Fallback

	   If none of the above works, the last parser installed on the user's system will be used. The XML::SAX package ships with a pure perl
	   XML parser, XML::SAX::PurePerl, so that there will always be a fallback parser.

AUTHOR

       Matt Sergeant, matt@sergeant.org

LICENSE

       This is free software, you may use it and distribute it under the same terms as Perl itself.

perl v5.18.2							    2009-10-10						     SAX::ParserFactory(3)