Data::Grove(3) User Contributed Perl Documentation Data::Grove(3)
NAME
Data::Grove -- support for deeply nested structures
SYNOPSIS
use Data::Grove;
$object = MyPackage->new;
package MyPackage;
@ISA = qw{Data::Grove};
DESCRIPTION
"Data::Grove" provides support for deeply nested tree or graph
structures. "Data::Grove" is intended primarily for Perl module authors
writing modules with many types or classes of objects that need to be
manipulated and extended in a consistent and flexible way.
"Data::Grove" is best used by creating a core set of ``data'' classes and
then incrementally adding functionality to the core data classes by using
``extension'' modules. One reason for this design is so that the data
classes can be swapped out and the extension modules can work with new
data sources. For example, these other data sources could be disk-based,
network-based or built on top of a relational database.
Two extension modules that come with "Data::Grove" are
"Data::Grove::Parent" and "Data::Grove::Visitor". "Data::Grove::Parent"
adds a `"Parent"' property to grove objects and implements a `"root"'
method to grove objects to return the root node of the tree from anywhere
in the tree and a `"rootpath"' method to return a list of nodes between
the root node and ``this'' node. "Data::Grove::Visitor" adds callback
methods `"accept"' and `"accept_name"' that call your handler or receiver
module back by object type name or the object's name.
"Data::Grove" objects do not contain parent references, Perl garbage
collection will delete them when no longer referenced and sub-structures
can be shared among several structures. "Data::Grove::Parent" is used to
create temporary objects with parent pointers.
Properties of data classes are accessed directly using Perl's hash
functions (i.e. `"$object->{Property}"'). Extension modules may also
define properties that they support or use, for example
Data::Grove::Parent adds `"Parent"' and `"Raw"' properties and Visitor
depends on `"Name"' and `"Content"' properties.
See the module "XML::Grove" for an example implementation of
"Data::Grove".
METHODS
new( PROPERTIES )
Return a new object blessed into the SubClass, with the given
properties. PROPERTIES may either be a list of key/value pairs, a
single hash containing key/value pairs, or an existing "Data::Grove"
object. If an existing "Data::Grove" is passed to `"new()"', a
shallow copy of that object will be returned. A shallow copy means
that you are returned a new object, but all of the objects underneath
still refer to the original objects.
AUTHOR
Ken MacLeod, ken@bitsko.slc.ut.us
SEE ALSO
perl(1)
perl v5.34.0 2003-10-21 Data::Grove(3)
libxml-perl 0.80.0 - Generated Sat Aug 20 11:09:05 CDT 2022