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, [email protected]
perl(1), PerlSAX.pod(3)