XML::TreePP(3) User Contributed Perl Documentation XML::TreePP(3)NAMEXML::TreePP-- Pure Perl implementation for parsing/writing XML
documents
SYNOPSIS
parse an XML document from file into hash tree:
use XML::TreePP;
my $tpp = XML::TreePP->new();
my $tree = $tpp->parsefile( "index.rdf" );
print "Title: ", $tree->{"rdf:RDF"}->{item}->[0]->{title}, "\n";
print "URL: ", $tree->{"rdf:RDF"}->{item}->[0]->{link}, "\n";
write an XML document as string from hash tree:
use XML::TreePP;
my $tpp = XML::TreePP->new();
my $tree = { rss => { channel => { item => [ {
title => "The Perl Directory",
link => "http://www.perl.org/",
}, {
title => "The Comprehensive Perl Archive Network",
link => "http://cpan.perl.org/",
} ] } } };
my $xml = $tpp->write( $tree );
print $xml;
get a remote XML document by HTTP-GET and parse it into hash tree:
use XML::TreePP;
my $tpp = XML::TreePP->new();
my $tree = $tpp->parsehttp( GET => "http://use.perl.org/index.rss" );
print "Title: ", $tree->{"rdf:RDF"}->{channel}->{title}, "\n";
print "URL: ", $tree->{"rdf:RDF"}->{channel}->{link}, "\n";
get a remote XML document by HTTP-POST and parse it into hash tree:
use XML::TreePP;
my $tpp = XML::TreePP->new( force_array => [qw( item )] );
my $cgiurl = "http://search.hatena.ne.jp/keyword";
my $keyword = "ajax";
my $cgiquery = "mode=rss2&word=".$keyword;
my $tree = $tpp->parsehttp( POST => $cgiurl, $cgiquery );
print "Link: ", $tree->{rss}->{channel}->{item}->[0]->{link}, "\n";
print "Desc: ", $tree->{rss}->{channel}->{item}->[0]->{description}, "\n";
DESCRIPTIONXML::TreePP module parses an XML document and expands it for a hash
tree. This generates an XML document from a hash tree as the opposite
way around. This is a pure Perl implementation and requires no modules
depended. This can also fetch and parse an XML document from remote
web server like the XMLHttpRequest object does at JavaScript language.
EXAMPLES
Parse XML file
Sample XML document:
<?xml version="1.0" encoding="UTF-8"?>
<family name="Kawasaki">
<father>Yasuhisa</father>
<mother>Chizuko</mother>
<children>
<girl>Shiori</girl>
<boy>Yusuke</boy>
<boy>Kairi</boy>
</children>
</family>
Sample program to read a xml file and dump it:
use XML::TreePP;
use Data::Dumper;
my $tpp = XML::TreePP->new();
my $tree = $tpp->parsefile( "family.xml" );
my $text = Dumper( $tree );
print $text;
Result dumped:
$VAR1 = {
'family' => {
'-name' => 'Kawasaki',
'father' => 'Yasuhisa',
'mother' => 'Chizuko',
'children' => {
'girl' => 'Shiori'
'boy' => [
'Yusuke',
'Kairi'
],
}
}
};
Details:
print $tree->{family}->{father}; # the father's given name.
The prefix '-' is added on every attribute's name.
print $tree->{family}->{"-name"}; # the family name of the family
The array is used because the family has two boys.
print $tree->{family}->{children}->{boy}->[1]; # The second boy's name
print $tree->{family}->{children}->{girl}; # The girl's name
Text node and attributes:
If a element has both of a text node and attributes or both of a text
node and other child nodes, value of a text node is moved to "#text"
like child nodes.
use XML::TreePP;
use Data::Dumper;
my $tpp = XML::TreePP->new();
my $source = '<span class="author">Kawasaki Yusuke</span>';
my $tree = $tpp->parse( $source );
my $text = Dumper( $tree );
print $text;
The result dumped is following:
$VAR1 = {
'span' => {
'-class' => 'author',
'#text' => 'Kawasaki Yusuke'
}
};
The special node name of "#text" is used because this elements has
attribute(s) in addition to the text node. See also "text_node_key"
option.
METHODS
new
This constructor method returns a new XML::TreePP object with %options.
$tpp = XML::TreePP->new( %options );
set
This method sets a option value for "option_name". If $option_value is
not defined, its option is deleted.
$tpp->set( option_name => $option_value );
See OPTIONS section below for details.
get
This method returns a current option value for "option_name".
$tpp->get( 'option_name' );
parse
This method reads an XML document by string and returns a hash tree
converted. The first argument is a scalar or a reference to a scalar.
$tree = $tpp->parse( $source );
parsefile
This method reads an XML document by file and returns a hash tree
converted. The first argument is a filename.
$tree = $tpp->parsefile( $file );
parsehttp
This method receives an XML document from a remote server via HTTP and
returns a hash tree converted.
$tree = $tpp->parsehttp( $method, $url, $body, $head );
$method is a method of HTTP connection: GET/POST/PUT/DELETE $url is an
URI of an XML file. $body is a request body when you use POST method.
$head is a request headers as a hash ref. LWP::UserAgent module or
HTTP::Lite module is required to fetch a file.
( $tree, $xml, $code ) = $tpp->parsehttp( $method, $url, $body, $head );
In array context, This method returns also raw XML document received
and HTTP response's status code.
write
This method parses a hash tree and returns an XML document as a string.
$source = $tpp->write( $tree, $encode );
$tree is a reference to a hash tree.
writefile
This method parses a hash tree and writes an XML document into a file.
$tpp->writefile( $file, $tree, $encode );
$file is a filename to create. $tree is a reference to a hash tree.
OPTIONS FOR PARSING XML
This module accepts option parameters following:
force_array
This option allows you to specify a list of element names which should
always be forced into an array representation.
$tpp->set( force_array => [ 'rdf:li', 'item', '-xmlns' ] );
The default value is null, it means that context of the elements will
determine to make array or to keep it scalar or hash. Note that the
special wildcard name '*' means all elements.
force_hash
This option allows you to specify a list of element names which should
always be forced into an hash representation.
$tpp->set( force_hash => [ 'item', 'image' ] );
The default value is null, it means that context of the elements will
determine to make hash or to keep it scalar as a text node. See also
"text_node_key" option below. Note that the special wildcard name '*'
means all elements.
cdata_scalar_ref
This option allows you to convert a cdata section into a reference for
scalar on parsing an XML document.
$tpp->set( cdata_scalar_ref => 1 );
The default value is false, it means that each cdata section is
converted into a scalar.
user_agent
This option allows you to specify a HTTP_USER_AGENT string which is
used by parsehttp() method.
$tpp->set( user_agent => 'Mozilla/4.0 (compatible; ...)' );
The default string is 'XML-TreePP/#.##', where '#.##' is substituted
with the version number of this library.
http_lite
This option forces pasrsehttp() method to use a HTTP::Lite instance.
my $http = HTTP::Lite->new();
$tpp->set( http_lite => $http );
lwp_useragent
This option forces pasrsehttp() method to use a LWP::UserAgent
instance.
my $ua = LWP::UserAgent->new();
$ua->timeout( 60 );
$ua->env_proxy;
$tpp->set( lwp_useragent => $ua );
You may use this with LWP::UserAgent::WithCache.
base_class
This blesses class name for each element's hashref. Each class is
named straight as a child class of it parent class.
$tpp->set( base_class => 'MyElement' );
my $xml = '<root><parent><child key="val">text</child></parent></root>';
my $tree = $tpp->parse( $xml );
print ref $tree->{root}->{parent}->{child}, "\n";
A hash for <child> element above is blessed to
"MyElement::root::parent::child" class. You may use this with
Class::Accessor.
elem_class
This blesses class name for each element's hashref. Each class is
named horizontally under the direct child of "MyElement".
$tpp->set( base_class => 'MyElement' );
my $xml = '<root><parent><child key="val">text</child></parent></root>';
my $tree = $tpp->parse( $xml );
print ref $tree->{root}->{parent}->{child}, "\n";
A hash for <child> element above is blessed to "MyElement::child"
class.
xml_deref
This option dereferences the numeric character references, like ë,
漢, etc., in an XML document when this value is true.
$tpp->set( xml_deref => 1 );
Note that, for security reasons and your convenient, this module
dereferences the predefined character entity references, &, <,
>, ' and ", and the numeric character references up to
U+007F without xml_deref per default.
OPTIONS FOR WRITING XML
first_out
This option allows you to specify a list of element/attribute names
which should always appears at first on output XML document.
$tpp->set( first_out => [ 'link', 'title', '-type' ] );
The default value is null, it means alphabetical order is used.
last_out
This option allows you to specify a list of element/attribute names
which should always appears at last on output XML document.
$tpp->set( last_out => [ 'items', 'item', 'entry' ] );
indent
This makes the output more human readable by indenting appropriately.
$tpp->set( indent => 2 );
This doesn't strictly follow the XML specification but does looks nice.
xml_decl
This module inserts an XML declaration on top of the XML document
generated per default. This option forces to change it to another or
just remove it.
$tpp->set( xml_decl => '' );
output_encoding
This option allows you to specify a encoding of the XML document
generated by write/writefile methods.
$tpp->set( output_encoding => 'UTF-8' );
On Perl 5.8.0 and later, you can select it from every encodings
supported by Encode.pm. On Perl 5.6.x and before with Jcode.pm, you can
use "Shift_JIS", "EUC-JP", "ISO-2022-JP" and "UTF-8". The default value
is "UTF-8" which is recommended encoding.
OPTIONS FOR BOTH
utf8_flag
This makes utf8 flag on for every element's value parsed and makes it
on for the XML document generated as well.
$tpp->set( utf8_flag => 1 );
Perl 5.8.1 or later is required to use this.
attr_prefix
This option allows you to specify a prefix character(s) which is
inserted before each attribute names.
$tpp->set( attr_prefix => '@' );
The default character is '-'. Or set '@' to access attribute values
like E4X, ECMAScript for XML. Zero-length prefix '' is available as
well, it means no prefix is added.
text_node_key
This option allows you to specify a hash key for text nodes.
$tpp->set( text_node_key => '#text' );
The default key is "#text".
ignore_error
This module calls Carp::croak function on an error per default. This
option makes all errors ignored and just returns.
$tpp->set( ignore_error => 1 );
use_ixhash
This option keeps the order for each element appeared in XML.
Tie::IxHash module is required.
$tpp->set( use_ixhash => 1 );
This makes parsing performance slow. (about 100% slower than default)
AUTHOR
Yusuke Kawasaki, http://www.kawa.net/
COPYRIGHT AND LICENSE
Copyright (c) 2006-2009 Yusuke Kawasaki. All rights reserved. This
program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
perl v5.14.0 2009-06-30 XML::TreePP(3)
