Data::Grove::Parent

Data::Grove::Parent(3User Contributed Perl DocumentatioData::Grove::Parent(3)



NAME
       Data::Grove::Parent - provide parent properties to Data::Grove objects

SYNOPSIS
	use Data::Grove::Parent;

	$root = $object->root;
	$rootpath = $object->rootpath;
	$tied = $object->add_magic([ $parent ]);

	$node = Data::Grove::Parent->new($hash [, $parent]);
	$node_list = Data::Grove::ParentList->new($array [, $parent]);

DESCRIPTION
       Data::Grove::Parent is an extension to Data::Grove that adds ‘"Par-
       ent"’ and ‘"Raw"’ properties to Data::Grove objects and methods for
       returning the root node of a grove, a list of nodes between and
       including the root node and the current node, and a method that cre-
       ates parented nodes.

       Data::Grove::Parent works by creating a Perl ‘‘tied’’ object that con-
       tains a parent reference (‘"Parent"’) and a reference to the original
       Data::Grove object (‘"Raw"’).  Tying-magic is used so that every time
       you reference the Data::Grove::Parent object it actually references
       the underlying raw object.

       When you retrieve a list or a property of the Raw object,
       Data::Grove::Parent automatically adds magic to the returned list or
       node.  This means you only call ‘add_magic()’ once to create the first
       Data::Grove::Parent object and then use the grove objects like you
       normally would.

       The most obvious use of this is so you don’t have to call a ‘"delete"’
       method when you want to release a grove or part of a grove; since
       Data::Grove and Data::Grove::Parent objects have no cyclic references,
       Perl can garbage collect them normally.

       A secondary use is to allow you to reuse grove or property set frag-
       ments in multiple trees.	 WARNING: Data::Grove currently does not pro-
       tect you from creating your own cyclic references!  This could lead to
       infinite loops if you don’t take care to avoid them.

METHODS
       $object->root()
       $object->rootpath()
	   ‘"root()"’ returns the root node if ‘$object’ is a
	   ‘"Data::Grove::Parent"’ object.  ‘"rootpath()"’ returns an array
	   of all the nodes between and including the root node and
	   ‘$object’.

       $tied = $object->add_magic([ $parent ])
	   ‘"add_magic()"’ returns a "Data::Grove::Parent" object with
	   ‘$object’ as it’s ‘"Raw"’ object.  If ‘$parent’ is given, that
	   becomes the tied object’s parent object.

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

SEE ALSO
       perl(1), Data::Grove(3)



perl v5.8.5			  2000-02-22	       Data::Grove::Parent(3)