AnyData::Format::XML(3pm)				User Contributed Perl Documentation				 AnyData::Format::XML(3pm)

NAME

	AnyData::Format::XML - tiedhash and DBI access to XML

SYNOPSIS

	# access XML data via a multi-dimensional tied hash
	# see AnyData.pod for full details
	#
	use AnyData;
	my $table = adTie( 'XML', $file, $mode, $flags );

	OR

	# convert data to and from XML
	# see AnyData.pod for full details
	#
	use AnyData;
	adConvert( 'XML', $file1, $any_other_format, $file2, $flags );
	adConvert( $any_other_format, $file1, 'XML', $file2, $flags );

	OR

	# access the data via DBI and SQL
	# see DBD::AnyData.pod for full details
	#
	use DBI;
	my $dbh = DBI->connect( 'dbi:AnyData' );
	$dbh->func('mytable','XML',$file,$flags,'ad_catalog');

       See below for a description of the optional flags that apply to all of these examples.

DESCRIPTION

       This module allows you to create, search, modify and/or convert XML data and files by treating them as databases without having to actually
       create separate database files.	The data can be accessed via a multi-dimensional tiedhash using AnyData.pm or via DBI and SQL commands
       using DBD::AnyData.pm.  See those modules for complete details of usage.

       The module is built on top of Michel Rodriguez's excellent XML::Twig which means that the AnyData interfaces can now include information
       from DTDs, be smarter about inferring data structure, reduce memory consumption on huge files, and provide access to many powerful features
       of XML::Twig and XML::Parser on which it is based.

       Importing options allow you to import/access/modify XML of almost any length or complexity.  This includes the ability to access different
       subtrees as separate or joined databases.

       Exporting and converting options allow you to take data from almost any source (a perl array, any DBI database, etc.) and output it as an
       XML file.  You can control the formating of the resulting XML either by supplying a DTD listing things like nesting of tags and which
       columns should be output as attributes and/or you can use XML::Twig pretty_print settings to generate half a dozen different levels of
       compactness or whitespace in how the XML looks.

       The documentation below outlines the special flags that can be used in either of the interfaces to fine-tune how the XML is treated.

       The flags listed below define the relationship between tags and attributes in the XML document and columns in the resulting database.  In
       many cases, you can simply accept the defaults and the database will be built automatically.  However, you can also fine tune the
       generation of the database by specifying which tags and attributes you are interested in and their relationship with database columns.

USAGE

   Prerequisites
       To use the tied hash interface, you will need

	AnyData
	XML::Twig
	XML::Parser

       To use the DBI/SQL interface, you will need those, and also

	DBI
	DBD::AnyData

   Required flags ( none )
       If no flags are specified, then the module determines the database structure from examining the file or data itself, making use of the DTD
       if there is one, otherwise scanning the first child of the XML tree for structural information.

   Optional flags
	If the default behavior is not sufficient, you may either specify a
	"record_tag" which will be used to define column names, or you can define an
	entire tag-to-column mapping.

       For simple XML, no flags are necessary:

	<table>
	   <row row_id="1"><name>Joe</name><location>Seattle</location></row>
	   <row row_id="2"><name>Sue</name><location>Portland</location></row>
	</table>

       The record_tag will default to the first child, namely "row".  The column names will be generated from the attributes of the record tag and
       all of the tags included under the record tag, so the column names in this example will be "row_id","name","location".

       If the record_tag is not the first child, you will need to specify it.  For example:

	<db>
	  <table table_id="1">
	    <row row_id="1"><name>Joe</name><location>Seattle</location></row>
	    <row row_id="2"><name>Sue</name><location>Portland</location></row>
	  </table>
	  <table table_id="2">
	    <row row_id="1"><name>Bob</name><location>Boise</location></row>
	    <row row_id="2"><name>Bev</name><location>Billings</location></row>
	  </table>
	</db>

       In this case you will need to specify "row" as the record_tag since it is not the first child of the tree.  The column names will be
       generated from the attributes of row's parent (if the parent is not the root), from row's attributes and sub tags, i.e.
       "table_id","row_id","name","location".

       In some cases you will need to specify an entire tag-to-column mapping.	For example, if you want to use a different name for the database
       column than is used in the XML (especially if the XML tag is not a valid SQL column name).  You'd also need to specify a mapping if there
       are two tags with the same name in different places in the XML tree.

       The column mapping is a reference to an array of column definitions.  A column definition is either a simple name of a tag, or a hash
       reference with the key containing the full path of the XML tag and the value containing the desired column name alias.

       For example:

	 col_map => [ 'part_id', 'part_name', 'availability' ];

       That will find the first three tags with those names and create the database using the same names for the tags.

       Or:

	 col_map => [
		      { '/parts/shop/id'	=> 'shop_id'},
		      { '/parts/shop/part/id'	=> 'part_id'},
		      { '/parts/shop/part/name' => 'part_name'},
		    ];

       That would find the three tags referenced on the left and create a database with the three column names referenced on the right.

       When exporting XML, you can specify a DTD to control the output.  For example, if you import a table from CSV or from an Array, you can
       output as XML and specify which of the columns become tags and which become attributes and also specify the nesting of the tags in your
       DTD.

       The XML format parser is built on top of Michel Rodriguez's excellent XML::Twig which is itslef based on XML::Parser.  Parameters to either
       of those modules may be passed in the flags for adTie() and the other commands including the "prettyPrint" flag to specify how the output
       XML is displayed and things like ProtocolEncoding.  ProtocolEncoding defaults to 'ISO-8859-1', all other flags keep the defaults of
       XML::Twig and XML::Parser.  See the documentation of those modules for details;

	CAUTION: Unlike other formats, the XML format does not save changes to
	the file as they are entered, but only saves the changes when you explicitly
	request them to be saved with the adExport() command.

AUTHOR &; COPYRIGHT
       copyright 2000, Jeff Zucker <jeff@vpservices.com> all rights reserved

perl v5.10.1							    2010-01-03						 AnyData::Format::XML(3pm)