Tree::Simple::Visitor:UsermContributeTree::Simple::Visitor::FromNestedArray(3)NAMETree::Simple::Visitor::FromNestedArray - A Visitor for creating
Tree::Simple objects from nested array trees.
SYNOPSIS
use Tree::Simple::Visitor::FromNestedArray;
my $visitor = Tree::Simple::Visitor::FromNestedArray->new();
# given this nested array tree
my $array_tree = [
'Root', [
'Child1', [
'GrandChild1',
'GrandChild2'
],
'Child2'
]
];
# set the array tree we
# are going to convert
$visitor->setArrayTree($array_tree);
$tree->accept($visitor);
# this then creates the equivalent Tree::Simple object:
# Tree::Simple->new("Root")
# ->addChildren(
# Tree::Simple->new("Child1")
# ->addChildren(
# Tree::Simple->new("GrandChild1"),
# Tree::Simple->new("GrandChild2")
# ),
# Tree::Simple->new("Child2"),
# );
DESCRIPTION
Given a tree constructed from nested arrays, this Visitor will create
the equivalent Tree::Simple heirarchy.
METHODS
new There are no arguments to the constructor the object will be in its
default state. You can use the "setNodeFilter", "includTrunk" and
"setArrayTree" methods to customize its behavior.
includTrunk ($boolean)
Setting the $boolean value to true (1) will cause the node value of
the $tree object passed into "visit" to be set with the root value
found in the $array_tree. Setting it to false (0), or not setting
it, will result in the first value in the $array_tree creating a
new node level.
setNodeFilter ($filter_function)
This method accepts a CODE reference as its $filter_function
argument and throws an exception if it is not a code reference.
This code reference is used to filter the tree nodes as they are
created, the $filter_function is passed the node value extracted
from the array prior to it being inserted into the tree being
built. The $filter_function is expected to return the value desired
for inclusion into the tree.
setArrayTree ($array_tree)
This method is used to set the $array_tree that our Tree::Simple
heirarchy will be constructed from. It must be in the following
form:
[
'Root', [
'Child1', [
'GrandChild1',
'GrandChild2'
],
'Child2'
]
]
Basically each element in the array is considered a node, unless it
is an array reference, in which case it is interpreted as
containing the children of the node created from the previous
element in the array.
The tree is validated prior being accepted, if it fails validation
an execption will be thrown. The rules are as follows;
The array tree must not be empty.
It makes not sense to create a tree out of nothing, so it is
assumed that this is a sign of something wrong.
All nodes of the array tree must not be array references.
The root node is validated against this in this function, but
all subsequent nodes are checked as the tree is built. Any
nodes found to be array references are rejected and an
exception is thrown. If you desire your node values to be array
references, you can use the node filtering mechanism to acheive
this as the node is filtered after it is validated.
The array tree must be a single rooted tree.
If there is a second element in the array tree, it is assumed
to be the children of the root, and therefore must be in the
form of an array reference.
visit ($tree)
This is the method that is used by Tree::Simple's "accept" method.
It can also be used on its own, it requires the $tree argument to
be a Tree::Simple object (or derived from a Tree::Simple object),
and will throw and exception otherwise.
BUGS
None that I am aware of. Of course, if you find a bug, let me know, and
I will be sure to fix it.
CODE COVERAGE
See the CODE COVERAGE section in Tree::Simple::VisitorFactory for more
inforamtion.
SEE ALSO
These Visitor classes are all subclasses of Tree::Simple::Visitor,
which can be found in the Tree::Simple module, you should refer to that
module for more information.
AUTHOR
stevan little, <stevan@iinteractive.com>
COPYRIGHT AND LICENSE
Copyright 2004, 2005 by Infinity Interactive, Inc.
<http://www.iinteractive.com>
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
perl v5.14.1200Tree::Simple::Visitor::FromNestedArray(3)
