NAME
XML::Handler::ExtOn - The handler for expansion of Perl SAX by objects.
SYNOPSYS
use XML::Handler::ExtOn;For write XML:
use XML::Handler::ExtOn;
my $buf;
my $wrt = XML::SAX::Writer->new( Output => \$buf );
my $ex_parser = new XML::Handler::ExtOn:: Handler => $wrt;
$ex_parser->start_document;
my $root = $ex_parser->mk_element("Root");
$root->add_namespace(
"myns" => 'http://example.com/myns',
"myns_test", 'http://example.com/myns_test'
);
$ex_parser->start_element( $root );
my $el = $root->mk_element('vars');
%{ $el->attrs_by_prefix("myns") } = ( v1 => 1, v2 => 3 );
%{ $el->attrs_by_prefix("myns_test") } =
( var1 => "test ns", var2 => "2333" );
$root->add_content($el);
$ex_parser->end_element;
$ex_parser->end_document;
print $buf;Result:
<?xml version="1.0"?>
<Root xmlns:myns="http://example.com/myns"
xmlns:myns_test="http://example.com/myns_test">
<vars myns_test:var2="2333"
myns_test:var1="test ns"
myns:v1="1" myns:v2="3"/>
</Root>For handle events
use base 'XML::Handler::ExtOn';Begin method for handle SAX event start_element:
sub on_start_element {
my ( $self, $elem ) = @_;
...Check localname for element and add tag image:
if ( $elem->local_name eq 'gallery' ) {
$elem->add_content(
$self->mk_element('image')->add_content(
$self->mk_characters( "Image number: $_" )
)
) for 1..2 ;
}XML Before:
<?xml version="1.0"?>
<Document>
<gallery/>
</Document>After:
<?xml version="1.0"?>
<Document>
<gallery>
<image>Image number: 1</image>
<image>Image number: 2</image>
</gallery>
</Document>Register namespace and set variables
$elem->add_namespace('demons','http://example.org/demo_namespace');
$elem->add_namespace('ns2','http://example.org/ns2');
#set attributes for name space
my $demo_attrs = $elem->attrs_by_prefix('demons');
%{$demo_attrs} = ( variable1=>1, 'variable2'=>2);
#set attributes for namespace URI
my $ns2_attrs = $elem->attrs_by_ns_uri('http://example.org/ns2');
%{$ns2_attrs} = ( var=> 'ns1', 'raw'=>2);Result:
<sub xmlns:demons="http://example.org/demo_namespace"
xmlns:ns2="http://example.org/ns2"
demons:variable2="2" ns2:var="ns1"
demons:variable1="1" ns2:raw="2"/>Delete content of element
if ( $elem->local_name eq 'demo_delete') {
$elem->skip_content
}XML before:
<?xml version="1.0"?>
<Document>
<demo_delete>
<p>text</p>
</demo_delete>
</Document>After:
<?xml version="1.0"?>
<Document>
<demo_delete/>
</Document>Add XML:
$elem->add_content (
$self->mk_from_xml('<custom><p>text</p></custom>')
)
Can add element after current
...
return [ $elem, $self->mk_element("after") ];
}DESCRIPTION
XML::Handler::ExtOn - SAX Handler designed for funny work with XML. It provides an easy-to-use interface for XML applications by adding objects.
XML::Handler::ExtOn override some SAX events. Each time an SAX event starts, a method by that name prefixed with `on_' is called with the "blessed" Element object to be processed.
XML::Handler::ExtOn implement the following methods:
on_start_document
on_start_prefix_mapping
on_start_element
on_end_element
on_characters
on_cdata
XML::Handler::ExtOn put all cdata characters into a single event on_cdata.
It compliant XML namespaces (http://www.w3.org/TR/REC-xml-names/), by support default namespace and namespace scoping.
XML::Handler::ExtOn provide methods for create XML, such as mk_element, mk_cdata ...
FUNCTIONS
create_pipe "flt_n1",$some_handler, $out_handler
use last arg as handler for out.
return parser ref.
my $h1 = new MyHandler1::;
my $filter = create_pipe( 'MyHandler1', $h1 );
$filter->parse('<root><p>TEST</p></root>');METHODS
on_start_document $document
Method handle start_document event. Usually override for initialaize default variables.
sub on_start_document {
my $self = shift;
$self->{_LINKS_ARRAY} = [];
$self->SUPER::on_start_document(@_);
}on_start_prefix_mapping prefix1=>ns_uri1[, prefix2=>ns_uri2]
Called on start_prefix_mapping event.
sub on_start_prefix_mapping {
my $self = shift;
my %map = @_;
$self->SUPER::start_prefix_mapping(@_)
}on_start_element $elem
Method handle on_start_element event whith XML::Handler::ExtOn::Element object.
Method must return $elem or ref to array of objects.
For example:
sub on_start_element {
my $self = shift;
my $elem = shift;
$elem->add_content( $self->mk_cdata("test"));
return $elem
}
...
return [ $elem, ,$self->mk_element("after_start_elem") ]
return [ $self->mk_element("before_start_elem"), $elem ]
...on_end_element $elem
Method handle on_end_element event whith XML::Handler::ExtOn::Element object. It call before end if element.
Method must return $elem or ref to array of objects.
For example:
sub on_end_element {
my $self = shift;
my $elem = shift;
if ( $elem->is_delete_element ) {
warn $elem->local_name . " deleted";
return [ $elem, $self->mk_element("after_deleted_elem") ]
};
return $elem
}
...
return [ $elem, ,$self->mk_element("after_close_tag_of_elem") ]
return [ $self->mk_element("before_close_tag_of_elem"), $elem ]
...on_characters( $self->current_element, $data->{Data} )
Must return string for write to stream.
sub on_characters {
my ( $self, $elem, $str ) = @_;
#lowercase all characters
return lc $str;
}on_cdata ( $current_element, $data )
Must return string for write to stream
sub on_cdata {
my ( $self, $elem, $str ) = @_;
return lc $str;
}mk_element <tag name>
Return object of element item for include to stream.
mk_from_xml <xml string>
Return command for include to stream.
mk_cdata $string | \$string
return command for insert cdata to stream
mk_characters $string | \$string
return command for insert characters to stream
current_element
Return link to current processing element.
add_namespace <Prefix> => <Namespace_URI>, [ <Prefix1> => <Namespace_URI1>, ... ]
Add Namespace mapping. return $self
If Prefix eq '', this namespace will then apply to all elements that have no prefix.
$elem->add_namespace(
"myns" => 'http://example.com/myns',
"myns_test", 'http://example.com/myns_test',
''=>'http://example.com/new_default_namespace'
);SEE ALSO
XML::Handler::ExtOn::Element, XML::SAX::Base
AUTHOR
Zahatski Aliaksandr, <zag@cpan.org>
COPYRIGHT AND LICENSE
Copyright (C) 2007-2008 by Zahatski Aliaksandr
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.8 or, at your option, any later version of Perl 5 you may have available.