XML::ExtOn - The handler for expansion of Perl SAX by objects.

    use XML::ExtOn;

For write XML:

    use XML::ExtOn;
    my $buf;
    my $wrt = XML::ExtOn::Writer->new( Output => \$buf );
    my $ex_parser = new XML::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::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") ];
    }

XML::ExtOn - SAX Handler designed for funny work with XML. It provides an easy-to-use interface for XML applications by adding objects.

XML::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::ExtOn implement the following methods:

* on_start_document

* on_start_prefix_mapping

* on_start_element

* on_end_element

* on_characters

* on_cdata

XML::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::ExtOn provide methods for create XML, such as mk_element, mk_cdata ...

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>');
    #also create pipe of pipes
    my $filter1 = create_pipe( 'MyHandler1', 'MyHandler2' );
    my $h1     = new MyHandler3::;
    my $filter2 = create_pipe(  $filter1, $h1);

return ref to array of filters in pipe

    use XML::ExtOn qw(split_pipe create_pipe);
    my $filter = create_pipe( 'MyHandler1', 'MyHandler2','MyHandler3');
    my $ref = @{ split_pipe( $filter) } [-1];
    isa_ok $ref,  'MyHandler3', 'check last element';

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(@_);
    }

Called on start_prefix_mapping event.

    sub on_start_prefix_mapping {
        my $self = shift;
        my %map  = @_;
        $self->SUPER::start_prefix_mapping(@_)
    }

Method handle on_start_element event whith XML::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 ]
    ...

Method handle on_end_element event whith XML::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 ]
    ...

Must return string for write to stream.

    sub on_characters {
        my ( $self, $elem, $str ) = @_;
        #lowercase all characters
        return lc $str;
    }

Must return string for write to stream

    sub on_cdata {
        my ( $self, $elem, $str ) = @_;
        return lc $str;
    }

Return object of element item for include to stream.

Return command for include to stream.

return command for insert cdata to stream

return command for insert characters to stream

return command for start element event

return command for expand stack for element

return start tag command. (internal)

return end tag command. (internal)

return command for end element event

Return link to current processing element.

Return link to current root element in incoming stack. Used in start_element and end_element methods

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'
    );

XML::ExtOn::Element, XML::SAX::Base

Zahatski Aliaksandr, <zag@cpan.org>

Copyright (C) 2007-2009 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.