1Data::Grove::Parent(3)User Contributed Perl DocumentationData::Grove::Parent(3)
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6 Data::Grove::Parent - provide parent properties to Data::Grove objects
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9 use Data::Grove::Parent;
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11 $root = $object->root;
12 $rootpath = $object->rootpath;
13 $tied = $object->add_magic([ $parent ]);
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15 $node = Data::Grove::Parent->new($hash [, $parent]);
16 $node_list = Data::Grove::ParentList->new($array [, $parent]);
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19 Data::Grove::Parent is an extension to Data::Grove that adds `"Parent"'
20 and `"Raw"' properties to Data::Grove objects and methods for returning
21 the root node of a grove, a list of nodes between and including the
22 root node and the current node, and a method that creates parented
23 nodes.
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25 Data::Grove::Parent works by creating a Perl ``tied'' object that
26 contains a parent reference (`"Parent"') and a reference to the
27 original Data::Grove object (`"Raw"'). Tying-magic is used so that
28 every time you reference the Data::Grove::Parent object it actually
29 references the underlying raw object.
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31 When you retrieve a list or a property of the Raw object,
32 Data::Grove::Parent automatically adds magic to the returned list or
33 node. This means you only call `add_magic()' once to create the first
34 Data::Grove::Parent object and then use the grove objects like you
35 normally would.
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37 The most obvious use of this is so you don't have to call a `"delete"'
38 method when you want to release a grove or part of a grove; since
39 Data::Grove and Data::Grove::Parent objects have no cyclic references,
40 Perl can garbage collect them normally.
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42 A secondary use is to allow you to reuse grove or property set
43 fragments in multiple trees. WARNING: Data::Grove currently does not
44 protect you from creating your own cyclic references! This could lead
45 to infinite loops if you don't take care to avoid them.
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48 $object->root()
49 $object->rootpath()
50 `"root()"' returns the root node if `$object' is a
51 `"Data::Grove::Parent"' object. `"rootpath()"' returns an array of
52 all the nodes between and including the root node and `$object'.
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54 $tied = $object->add_magic([ $parent ])
55 `"add_magic()"' returns a "Data::Grove::Parent" object with
56 `$object' as it's `"Raw"' object. If `$parent' is given, that
57 becomes the tied object's parent object.
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60 Ken MacLeod, ken@bitsko.slc.ut.us
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63 perl(1), Data::Grove(3)
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67perl v5.16.3 2003-10-21 Data::Grove::Parent(3)