XML::Handler::XMLWriteUser Contributed Perl DocumentXML::Handler::XMLWriter(3)NAMEXML::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 ALSOperl(1), PerlSAX.pod(3)perl v5.8.8 2003-10-21 XML::Handler::XMLWriter(3)
