NAME
XML::Struct::Writer - Write XML data structures to XML streams
SYNOPSIS
use XML::Struct::Writer;
# serialize
XML::Struct::Writer->new(
to => \*STDOUT,
attributes => 0,
pretty => 1,
)->write( [
doc => [
[ name => [ "alice" ] ],
[ name => [ "bob" ] ],
]
] );
# <?xml version="1.0" encoding="UTF-8"?>
# <doc>
# <name>alice</name>
# <name>bob</name>
# </doc>
# create DOM
my $xml = XML::Struct::Writer->new->write( [
greet => { }, [
"Hello, ",
[ emph => { color => "blue" } , [ "World" ] ],
"!"
]
] );
$xml->toFile("greet.xml");
# <?xml version="1.0" encoding="UTF-8"?>
# <greet>Hello, <emph color="blue">World</emph>!</greet>
DESCRIPTION
This module writes an XML document, given as XML::Struct data structure, as stream of "SAX EVENTS". The default handler receives these events with XML::LibXML::SAX::Builder to build a DOM tree which can then be used to serialize the XML document as string. The writer can also be used to directly serialize XML with XML::Struct::Writer::Stream.
XML::Struct provides the shortcut function writeXML
to this module.
XML elements can be passed in any of these forms and its combinations:
# MicroXML:
[ $name => \%attributes, \@children ]
[ $name => \%attributes ]
[ $name ]
# lax MicroXML also:
[ $name => \@children ]
# SimpleXML:
{ $name => \@children, $name => $content, ... }
CONFIGURATION
A XML::Struct::Writer can be configured with the following options:
- to
-
Filename, IO::Handle, string reference, or other kind of stream to directly serialize XML to with XML::Struct::Writer::Stream. This option is ignored if
handler
is explicitly set. - handler
-
A SAX handler to send "SAX EVENTS" to. If neither this option nor
to
is explicitly set, an instance of XML::LibXML::SAX::Builder is used to build a DOM. - attributes
-
Ignore XML attributes if set to false. Set to true by default.
- xmldecl
-
Include XML declaration on serialization. Enabled by default.
- encoding
-
An encoding (for handlers that support an explicit encoding). Set to UTF-8 by default.
- version
-
The XML version. Set to
1.0
by default. - standalone
-
Add standalone flag in the XML declaration.
- pretty
-
Pretty-print XML. Disabled by default.
METHODS
write( $root [, $name ] ) == writeDocument( $root [, $name ] )
Write an XML document, given as array reference (lax MicroXML), hash reference (SimpleXML), or both mixed. If given as hash reference, the name of a root tag can be chosen or it is set to root
. This method is basically equivalent to:
$writer->writeStart;
$writer->writeElement(
$writer->microXML($root, $name // 'root')
);
$writer->writeEnd;
$writer->result if $writer->can('result');
The remaining methods expect XML in MicroXML format only.
writeElement( $element [, @more_elements ] )
Write one or more XML elements and their child elements to the handler.
writeStart( [ $root [, $name ] ] )
Call the handler's start_document
and xml_decl
methods. An optional root element can be passed, so $writer->writeStart($root)
is equivalent to:
$writer->writeStart;
$writer->writeStartElement($root);
writeStartElement( $element )
Directly call the handler's start_element
method.
writeEndElement( $element )
Directly call the handler's end_element
method.
writeCharacters( $string )
Directy call the handler's characters
method.
writeEnd( [ $root ] )
Directly call the handler's end_document
method. An optional root element can be passed, so $writer->writeEnd($root)
is equivalent to:
$writer->writeEndElement($root);
$writer->writeEnd;
microXML( $element [, $name ] )
Convert an XML element, given as array reference (lax MicroXML) or as hash reference (SimpleXML) to a list of MicroXML elements and optionally remove attributes. Does not affect child elements.
SAX EVENTS
A SAX handler, set with option handler
, is expected to implement the following methods (two of them are optional):
- xml_decl( { Version => $version, Encoding => $encoding } )
-
Optionally called once at the start of an XML document, if the handler supports this method.
- start_document()
-
Called once at the start of an XML document.
- start_element( { Name => $name, Attributes => \%attributes } )
-
Called at the start of an XML element to emit an XML start tag.
- end_element( { Name => $name } )
-
Called at the end of an XML element to emit an XML end tag.
- characters( { Data => $characters } )
-
Called for character data. Character entities and CDATA section are expanded to strings.
- end_document()
-
Called once at the end of an XML document.
- result()
-
Optionally called at the end of
write
/writeDocument
to return a value from this methods. Handlers do not need to implement this method.
SEE ALSO
Using a streaming SAX handler, such as XML::SAX::Writer, XML::Genx::SAXWriter, XML::Handler::YAWriter, and possibly XML::Writer should be more performant for serialization. Examples of other modules that receive SAX events include XML::STX, XML::SAX::SimpleDispatcher, and XML::SAX::Machines,