XML::Handler::Subs(3) User Contributed Perl Documentation XML::Handler::Subs(3)

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

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);

"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.

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

perl(1), PerlSAX.pod(3)
2020-07-07 perl v5.32.0