Config::Hierarchical::Delta - Comparator for hashes and Config::Hierarchical objects

	# comparing hashes:

	use Config::Hierarchical ; 
	use Config::Hierarchical::Delta qw (GetConfigDelta GetConfigHierarchicalDelta DumpConfigHierarchicalDelta Get_NoIdentical_Filter) ; 

	my $delta = GetConfigDelta
				(
				{name   => {A => 1, COMMON => 0}},
				{name_2 => {B => 2, COMMON => 0}}
				) ;

$delta is a reference to the following hash:

	{
	'in \'name\' only'   => {'A' => 1},
	'in \'name_2\' only' => {'B' => 2},
	'identical'          => {'COMMON' => 0},
	},

	# comparing Config Hierarchical objects:

	my $config_0 = new Config::Hierarchical
				(
				NAME => 'config 0',
				INITIAL_VALUES  =>
					[
					{NAME => 'CC1', VALUE => '1'},
					{NAME => 'CC2', VALUE => '2'},
					] ,
				) ;

	my $config_1 = new Config::Hierarchical
				(
				NAME => 'config 1',
				CATEGORY_NAMES   => ['A', 'B',],
				DEFAULT_CATEGORY => 'A',

				INITIAL_VALUES  =>
					[
					{CATEGORY => 'B', ALIAS => $config_0},

					{NAME => 'CC1', VALUE => '1'},
					{NAME => 'CC2', VALUE => '2'},
					{NAME => 'CC3', VALUE => '3'},
					] ,
				) ;

	$config_1->Set(NAME => 'CC1', VALUE => '1.1') ;

	my $config_2 = new Config::Hierarchical
				(
				NAME => 'config 2',

				CATEGORY_NAMES   => ['<A>', 'B',],
				DEFAULT_CATEGORY => 'A',
				INITIAL_VALUES   =>
					[
					{CATEGORY => 'B', ALIAS => $config_1},
					] ,
				) ;

	$config_2->Set(CATEGORY => 'A', NAME => 'CC1', VALUE => 'A', OVERRIDE => 1) ;
	$config_2->Set(CATEGORY => 'A', NAME => 'XYZ', VALUE => 'xyz') ;

	my $dump = DumpConfigHierarchicalDelta($config_2, $config_0) ;

$dump contains the following string:

	Delta between 'config 2' and 'config 0'':
	|- different 
	|  `- CC1 
	|     |- config 0 = 1 
	|     `- config 2 = A 
	|- identical 
	|  `- CC2 = 2 
	`- in 'config 2' only 
	   |- CC3 = 3 
	   `- XYZ = xyz 

This module lets you compare hashes and Config::Hierarchical objects.

	my $delta = GetConfigDelta
				(
				{name   => {A => 1, COMMON => 0}},
				{name_2 => {B => 2, COMMON => 0}}
				) ;

GetConfigDelta compares two hashes and returns a reference to a hash containing up to 4 elements. It takes as argument two hash reference which contain a single element. The key is used as name for the hash while the value is a reference to the hash to be compared.

Returned elements:

* identical

Contains all the elements that are identical in both hashes as well as the value they have

* different

Contains the elements that are common in both hashes but with different values

* in 'lhs' only

Contains the elements that exists in the first hash but not in the second hash .

* in 'rhs' only

Contains the elements that exists in the first hash but not in the second hash .

	my $config_1 = new Config::Hierarchical(...) ;
	my $config_2 = new Config::Hierarchical(...) ;

	GetConfigHierarchicalDelta($config_1, $config_2) ;

Compares two Config::Hierarchical objects and returns a reference to hash containing the delta between the objects. See GetConfigDeleta for a description of the returned hash.

The name of the Config::Variable object is extracted from the objects.

	my $config_1 = new Config::Hierarchical(...)
	my $config_2 = new Config::Hierarchical(...) ;

	print DumpConfigHierarchicalDelta($config_1, $config_2, QUOTE_VALUES => 1) ;

The first two arguments a Config::Hierarchical objects, the rest of the arguments are passed as is to Data::TreeDumper.

This sub returns a string containing the dump of the delta. See Synopsis for an output example.

Dumping a config delta with:

	print  DumpConfigHierarchicalDelta($config_2, $config_0) ;	

Gives:

	$expected_dump = <<EOD ;
	Delta between 'config 2' and 'config 0'':
	|- different 
	|  `- CC1 
	|     |- config 0 = 1 
	|     `- config 2 = A 
	|- identical 
	|  `- CC2 = 2 
	`- in 'config 2' only 
	   |- CC3 = 3 
	   `- XYZ = xyz 

if you do not want to display the configuration variables that are identical, use:

	print  DumpConfigHierarchicalDelta($config_2, $config_0, Get_NoIdentical_Filter()) ;

which gives:

	my $expected_dump = <<EOD ;
	Delta between 'config 2' and 'config 0'':
	|- different 
	|  `- CC1 
	|     |- config 0 = 1 
	|     `- config 2 = A 
	`- in 'config 2' only 
	   |- CC3 = 3 
	   `- XYZ = xyz 
	EOD

Returns a Data::TreeDumper filter you can use to remove the 'identical' element from the delta hash.

None so far.

	Khemir Nadim ibn Hamouda
	CPAN ID: NKH
	mailto:nadim@khemir.net

Copyright 2006-2007 Khemir Nadim. All rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

You can find documentation for this module with the perldoc command.

    perldoc Config::Hierarchical

You can also look for information at:

* AnnoCPAN: Annotated CPAN documentation

http://annocpan.org/dist/Config-Hierarchical

* RT: CPAN's request tracker

Please report any bugs or feature requests to L <bug-config-hierarchical@rt.cpan.org>.

We will be notified, and then you'll automatically be notified of progress on your bug as we make changes.

* Search CPAN

http://search.cpan.org/dist/Config-Hierarchical