xml::handler::subs(3pm)
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:
- new( OPTIONS )
- 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. - in_element($name)
- Returns true if `$name' is equal to the name of the innermost
currently opened element. - within_element($name)
- Returns the number of times the `$name' appears in Names.
AUTHOR
Ken MacLeod, ken@bitsko.slc.ut.us