# man > XML::Handler::XMLWriter(3pm)

## NAME
    [XML::Handler::XMLWriter](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AHandler%3A%3AXMLWriter/markdown) - a PerlSAX handler for writing readable XML

## SYNOPSIS
     use [XML::Parser::PerlSAX](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AParser%3A%3APerlSAX/markdown);
     use [XML::Handler::XMLWriter](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AHandler%3A%3AXMLWriter/markdown);

     $my_handler = [XML::Handler::XMLWriter](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AHandler%3A%3AXMLWriter/markdown)->new( I<OPTIONS> );

     [XML::Parser::PerlSAX](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AParser%3A%3APerlSAX/markdown)->new->parse(Source => { SystemId => 'REC-xml-19980210.xml' },
                                      Handler => $my_handler);

## DESCRIPTION
    "[XML::Handler::XMLWriter](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AHandler%3A%3AXMLWriter/markdown)" is a PerlSAX handler for writing readable XML (in contrast to
    Canonical XML, for example). [XML::Handler::XMLWriter](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AHandler%3A%3AXMLWriter/markdown) can be used with a parser to reformat XML,
    with [XML::DOM](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3ADOM/markdown) or [XML::Grove](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AGrove/markdown) to write out XML, or with other PerlSAX modules that generate
    events.

    "[XML::Handler::XMLWriter](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AHandler%3A%3AXMLWriter/markdown)" is intended to be used with PerlSAX event generators and does not
    perform any checking itself (for example, matching start and end element events). If you want to
    generate XML directly from your Perl code, use the [XML::Writer](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AWriter/markdown) module. [XML::Writer](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AWriter/markdown) has an easy
    to use interface and performs many checks to make sure that the XML you generate is well-formed.

    "[XML::Handler::XMLWriter](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AHandler%3A%3AXMLWriter/markdown)" is a subclass of "[XML::Handler::Subs](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AHandler%3A%3ASubs/markdown)". "[XML::Handler::XMLWriter](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AHandler%3A%3AXMLWriter/markdown)" can
    be further subclassed to alter it's behavior or to add element-specific handling. In the
    subclass, each time an element starts, a method by that name prefixed with `s_' is called with
    the element to be processed. Each time an element ends, a method with that name prefixed with
    `e_' is called. Any special characters in the element name are replaced by underscores. If there
    isn't a start or end method for an element, the default action is to write the start or end tag.
    Start and end methods can use the `"print_start_element()"' and `"print_end_element()"' methods
    to print start or end tags. Subclasses can call the `"print()"' method to write additional
    output.

    Subclassing [XML::Handler::XMLWriter](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AHandler%3A%3AXMLWriter/markdown) in this way is similar to [XML::Parser](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AParser/markdown)'s Stream style.

    [XML::Handler::Subs](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AHandler%3A%3ASubs/markdown) maintains a stack of element names, `"$self-"{Names}', and a stack of element
    nodes, `"$self-"{Nodes}>' that can be used by subclasses. The current element is pushed on the
    stacks before calling an element-name start method and popped off the stacks after calling the
    element-name end method.

    See [XML::Handler::Subs](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AHandler%3A%3ASubs/markdown) for additional methods.

    In addition to the standard PerlSAX handler methods (see PerlSAX for descriptions),
    [XML::Handler::XMLWriter](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AHandler%3A%3AXMLWriter/markdown) supports the following methods:

### new
        Creates and returns a new instance of [XML::Handler::XMLWriter](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AHandler%3A%3AXMLWriter/markdown) with the given *OPTIONS*.
        Options may be changed at any time by modifying them directly in the hash returned.
        *OPTIONS* can be a list of key, value pairs or a hash. The following *OPTIONS* are
        supported:

        Output
            An [IO::Handle](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3AHandle/markdown) or one of it's subclasses (such as [IO::File](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3AFile/markdown)), if this parameter is not
            present and the AsString option is not used, the module will write to standard output.

        AsString
            Return the generated XML as a string from the `"parse()"' method of the PerlSAX event
            generator.

        Newlines
            A true or false value; if this parameter is present and its value is true, then the
            module will insert an extra newline before the closing delimiter of start, end, and
            empty tags to guarantee that the document does not end up as a single, long line. If the
            parameter is not present, the module will not insert the newlines.

        IsSGML
            A true or false value; if this parameter is present and its value is true, then the
            module will generate SGML rather than XML.

### print_start_element
        Print a start tag for `$element'. This is the default action for the PerlSAX
        `"start_element()"' handler, but subclasses may use this if they define a start method for
        an element.

### print_end_element
        Prints an end tag for `$element'. This is the default action for the PerlSAX
        `"end_element()"' handler, but subclasses may use this if they define a start method for an
        element.

    print($output)
        Write `$output' to Output and/or append it to the string to be returned. Subclasses may use
        this to write additional output.

## TODO
    *   An Elements option that provides finer control over newlines than the Newlines option, where
        you can choose before and after newline for element start and end tags. Inspired by the
        Python XMLWriter.

    *   Support Doctype and XML declarations.

## AUTHOR
    Ken MacLeod, <ken@bitsko.slc.ut.us> This module is partially derived from [XML::Writer](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3AWriter/markdown) by David
    Megginson.

## SEE ALSO
### perl