NAME
XML::Hash::XS - Simple and fast hash to XML and XML to hash conversion
written in C
SYNOPSIS
use XML::Hash::XS;
my $xmlstr = hash2xml \%hash;
hash2xml \%hash, output => $fh;
my $hash = xml2hash $xmlstr;
my $hash = xml2hash \$xmlstr;
my $hash = xml2hash 'test.xml', encoding => 'cp1251';
my $hash = xml2hash $fh;
my $hash = xml2hash *STDIN;
Or OOP way:
use XML::Hash::XS qw();
my $conv = XML::Hash::XS->new(utf8 => 0, encoding => 'utf8')
my $xmlstr = $conv->hash2xml(\%hash, utf8 => 1);
my $hash = $conv->xml2hash($xmlstr, encoding => 'cp1251');
DESCRIPTION
This module implements simple hash to XML and XML to hash conversion
written in C.
During conversion uses minimum of memory, XML or hash is written
directly without building DOM.
Some features are optional and are available with appropriate libraries:
* XML::LibXML library is required in order to build DOM
* ICU or iconv library is required in order to perform charset
conversions
FUNCTIONS
hash2xml $hash, [ %options ]
$hash is reference to hash
hash2xml
{
node1 => 'value1',
node2 => [ 'value21', { node22 => 'value22' } ],
node3 => \'value3',
node4 => sub { return 'value4' },
node5 => sub { return { node51 => 'value51' } },
},
canonical => 1,
indent => 2,
;
will convert to:
<?xml version="1.0" encoding="utf-8"?>
<root>
<node1>value1</node1>
<node2>value21</node2>
<node2>
<node22>value22</node22>
</node2>
<node3>value3</node3>
<node4>value4</node4>
<node5>
<node51>value51</node51>
</node5>
</root>
and (use_attr=1):
hash2xml
{
node1 => 'value1',
node2 => [ 'value21', { node22 => 'value22' } ],
node3 => \'value3',
node4 => sub { return 'value4' },
node5 => sub { return { node51 => 'value51' } },
},
use_attr => 1,
canonical => 1,
indent => 2,
;
will convert to:
<?xml version="1.0" encoding="utf-8"?>
<root node1="value1" node3="value3" node4="value4">
<node2>value21</node2>
<node2 node22="value22"/>
<node5 node51="value51"/>
</root>
xml2hash $xml, [ %options ]
$xml may be string, reference to string, file handle or tied file
handle:
xml2hash '<root>text</root>';
# output: 'text'
xml2hash '<root a="1" b="2">text</root>';
# output: { a => '1', b => '2', content => 'text' }
open(my $fh, '<', 'test.xml');
xml2hash $fh;
xml2hash *STDIN;
OPTIONS
doc [ => 0 ] *# hash2xml*
if doc is '1', then returned value is XML::LibXML::Document.
root [ = 'root' ] *# hash2xml*
Root node name.
version [ = '1.0' ] *# hash2xml*
XML document version
encoding [ = 'utf-8' ] *# hash2xml+xml2hash*
XML input/output encoding
indent [ = 0 ] *# hash2xml*
if indent great than "0", XML output should be indented according to
its hierarchic structure. This value determines the number of
spaces.
if indent is "0", XML output will all be on one line.
output [ = undef ] *# hash2xml*
XML output method
if output is undefined, XML document dumped into string.
if output is FH, XML document writes directly to a filehandle or a
stream.
canonical [ = 0 ] *# hash2xml*
if canonical is "1", converter will be write hashes sorted by key.
if canonical is "0", order of the element will be pseudo-randomly.
use_attr [ = 0 ] *# hash2xml*
if use_attr is "1", converter will be use the attributes.
if use_attr is "0", converter will be use tags only.
content [ = undef ] *# hash2xml+xml2hash*
if defined that the key name for the text content(used only if
use_attr=1).
force_array => [ = undef ] *# xml2hash*
This option is similar to "ForceArray" from XMl::Simple module:
<https://metacpan.org/pod/XML::Simple#ForceArray-1-in---important>.
force_content => [ = 0 ] *# xml2hash*
This option is similar to "ForceContent" from XMl::Simple module:
<https://metacpan.org/pod/XML::Simple#ForceContent-1-in---seldom-use
d>.
merge_text [ = 0 ] *# xml2hash*
Setting this option to "1" will cause merge adjacent text nodes.
xml_decl [ = 1 ] *# hash2xml*
if xml_decl is "1", output will start with the XML declaration
'<?xml version="1.0" encoding="utf-8"?>'.
if xml_decl is "0", XML declaration will not be output.
trim [ = 0 ] *# hash2xml+xml2hash*
Trim leading and trailing whitespace from text nodes.
utf8 [ = 1 ] *# hash2xml+xml2hash*
Turn on utf8 flag for strings if enabled.
max_depth [ = 1024 ] *# xml2hash*
Maximum recursion depth.
buf_size [ = 4096 ] *# hash2xml+xml2hash*
Buffer size for reading end encoding data.
keep_root [ = 0 ] *# xml2hash*
Keep root element.
filter [ = undef ] *# xml2hash*
Filter nodes matched by pattern and return reference to array of
nodes.
Sample:
my $xml = <<'XML';
<root>
<item1>111</item1>
<item2>222</item2>
<item3>333</item3>
</root>
XML
my $nodes = xml2hash($xml, filter => '/root/item1');
# $nodes = [ 111 ]
my $nodes = xml2hash($xml, filter => ['/root/item1', '/root/item2']);
# $nodes = [ 111, 222 ]
my $nodes = xml2hash($xml, filter => qr[/root/item\d$]);
# $nodes = [ 111, 222, 333 ]
It may be used to parse large XML because does not require a lot of
memory.
cb [ = undef ] *# xml2hash*
This option is used in conjunction with "filter" option and defines
callback that will called for each matched node.
Sample:
xml2hash($xml, filter => qr[/root/item\d$], cb => sub {
print $_[0], "\n";
});
# 111
# 222
# 333
method [ = 'NATIVE' ] *# hash2xml*
experimental support the conversion methods other libraries
if method is 'LX' then conversion result is the same as using
XML::Hash::LX library
Note: for 'LX' method following additional options are available:
attr cdata text comm
OBJECT_SERIALISATION(hash2xml)
1. When object has a "toString" method
In this case, the <toString> method of object is invoked in scalar
context. It must return a single scalar that can be directly encoded
into XML.
Example:
use XML::LibXML;
local $XML::LibXML::skipXMLDeclaration = 1;
my $doc = XML::LibXML->new->parse_string('<foo bar="1"/>');
print hash2xml({ doc => $doc }, indent => 2, xml_decl => 0);
=>
<root>
<doc><foo bar="1"/></doc>
</root>
2. When object has a "iternext" method ("NATIVE" method only)
In this case, the <iternext> method method will invoke a few times
until the return value is not undefined.
Example:
my $count = 0;
my $o = bless {}, 'Iterator';
*Iterator::iternext = sub { $count++ < 3 ? { count => $count } : undef };
print hash2xml({ item => $o }, use_attr => 1, indent => 2, xml_decl => 0);
=>
<root>
<item count="1"/>
<item count="2"/>
<item count="3"/>
</root>
This can be used to generate a large XML using minimum memory, example
with DBI:
my $sth = $dbh->prepare('SELECT * FROM foo WHERE bar=?');
$sth->execute(...);
my $o = bless {}, 'Iterator';
*Iterator::iternext = sub { $sth->fetchrow_hashref() };
open(my $fh, '>', 'data.xml');
hash2xml({ row => $o }, use_attr => 1, indent => 2, xml_decl => 0, output => $fh);
=>
<root>
<row bar="..." ... />
<row bar="..." ... />
...
</root>
BENCHMARK
Performance benchmark in comparison with some popular modules(hash2xml):
Rate XML::Hash XML::Hash::LX XML::Simple XML::Hash::XS
XML::Hash 65.0/s -- -6% -37% -99%
XML::Hash::LX 68.8/s 6% -- -33% -99%
XML::Simple 103/s 58% 49% -- -98%
XML::Hash::XS 4879/s 7404% 6988% 4658% --
Benchmark was done on <http://search.cpan.org/uploads.rdf>
AUTHOR
Yuriy Ustushenko, <yoreek@yahoo.com>
COPYRIGHT AND LICENSE
Copyright (C) 2012-2017 Yuriy Ustushenko
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.