XML::Handler::XMLWriter

XML::Handler::XMLWriteUser Contributed Perl DocumentXML::Handler::XMLWriter(3)



NAME
       XML::Handler::XMLWriter - a PerlSAX handler for writing readable XML

SYNOPSIS
        use XML::Parser::PerlSAX;
        use XML::Handler::XMLWriter;

        $my_handler = XML::Handler::XMLWriter->new( I<OPTIONS> );

        XML::Parser::PerlSAX->new->parse(Source => { SystemId => 'REC-xml-19980210.xml' },
                                         Handler => $my_handler);

DESCRIPTION
       "XML::Handler::XMLWriter" is a PerlSAX handler for writing readable XML
       (in contrast to Canonical XML, for example).  XML::Handler::XMLWriter
       can be used with a parser to reformat XML, with XML::DOM or XML::Grove
       to write out XML, or with other PerlSAX modules that generate events.

       "XML::Handler::XMLWriter" 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 module.  XML::Writer
       has an easy to use interface and performs many checks to make sure that
       the XML you generate is well-formed.

       "XML::Handler::XMLWriter" is a subclass of "XML::Handler::Subs".
       "XML::Handler::XMLWriter" 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 char-
       acters 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 in this way is similar to
       XML::Parser's Stream style.

       XML::Handler::Subs 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 for additional methods.

       In addition to the standard PerlSAX handler methods (see PerlSAX for
       descriptions), XML::Handler::XMLWriter supports the following methods:

       new( OPTIONS )
           Creates and returns a new instance of XML::Handler::XMLWriter 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 or one of it's subclasses (such as IO::File), 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 paramter 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($element)
           Print a start tag for `$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($element)
           Prints an end tag for `$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
       o   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.

       o   Support Doctype and XML declarations.

AUTHOR
       Ken MacLeod, ken@bitsko.slc.ut.us This module is partially derived from
       XML::Writer by David Megginson.

SEE ALSO
       perl(1), PerlSAX.pod(3)



perl v5.8.6                       2003-10-21        XML::Handler::XMLWriter(3)