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

NAME SYNOPSIS DESCRIPTION AUTHOR SEE ALSO

NAME

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);

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, [email protected]