XML::Handler::Subs(3)

NAME
XML::Handler::Subs - a PerlSAX handler base class for calling user-defined subs

SYNOPSIS
 use XML::Handler::Subs;
 package MyHandlers;
 use vars qw{ @ISA };
 sub s_NAME { my ($self, $element) = @_ };
 sub e_NAME { my ($self, $element) = @_ };
 $self->{Names};    # an array of names
 $self->{Nodes};    # an array of $element nodes
 $handler = MyHandlers->new();
 $self->in_element($name);
 $self->within_element($name);

DESCRIPTION
`XML::Handler::Subs' is a base class for PerlSAX handlers. `XML::Handler::Subs' is subclassed to implement complete behavior and to add element-specific handling.

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.

Subclassing XML::Handler::Subs in this way is similar to XML::Parser's Subs 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. The ``in_element()'' and ``within_element()'' calls use these stacks.

If the subclass implements ``start_document()'', ``end_document()'', ``start_element()'', and ``end_element()'', be sure to use ``SUPER::'' to call the the superclass methods also. See perlobj(1) for details on SUPER::. ``SUPER::start_element()'' and ``SUPER::end_element()'' return 1 if an element-name method is called, they return 0 if no method was called.

XML::Handler::Subs does not implement any other PerlSAX handlers.

XML::Handler::Subs supports the following methods: A basic ``new()'' method. ``new()'' takes a list of key, value pairs or a hash and creates and returns a hash with those options; the hash is blessed into the subclass. Returns true if ``$name'' is equal to the name of the innermost currently opened element. Returns the number of times the ``$name'' appears in Names.

AUTHOR
Ken MacLeod, ken@bitsko.slc.ut.us

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