NAME

  Data::Stag::BaseHandler     - Base class for writing tag stream handlers

SYNOPSIS

  package MyPersonHandler;
  use base qw(Data::Stag::BaseHandler);


  # handler that prints person nodes as they are parsed
  sub e_person {
      my $self = shift;
      my $node = shift;
      printf "Person name:%s address:%s\n",
        $node->sget('name'), $node->sget('address');
      return [];  # delete person node
  }
  
  package MyPersonHandler;
  use base qw(Data::Stag::BaseHandler);

  # handler that modifies tree as it goes
  sub e_measurement {
      my $self = shift;
      my $node = shift;
      if ($node->sget('unit') eq 'inch') {
          $node->set('unit', 'cm');
          $node->set('quantity', $node->get('quantity') * 2.5);
      }
      return;   # returnig null leaves it unchanged
  }
  

DESCRIPTION

Default Simple Event Handler, other handlers inherit from this class

See also Data::Stag

This class catches Data::Stag node events (start, end and body) and allows the subclassing module to intercept these. Unintercepted events get pushed into a tree.

This class can take SAX events and turn them into simple Data::Stag events; mixed content and attributes are currently ignored. email me if you would like this behaviour changed.

the events recognised are

  start_event(node-name)
  evbody(node-data)
  end_event(node-name)

and also

  event(node-name, node-data|node)

which is just a wrapper for the other events

you can either intercept these methods; or you can define methods

  s_<element_name>
  e_<element_name>

that get called on the start/end of an event; you can dynamically change the structure of the tree by returning nodes from these methods

PUBLIC METHODS -

tree

  Usage   -
  Returns -
  Args    -